Digital encoder and digital-to-analog converter using same

A digital encoder having a dynamic element matching (DEM) processor is divided into a master DEM circuit and N slave DEM circuits. The master DEM circuit encodes a multibit digital input signal (IN 0 ) into parallel codes (C 1 ) corresponding to the coefficient of a plurality of output nodes on the basis of a prescribed DEM algorithm. Each of the N slave DEM means ( 2 ) has 3 or more output nodes. Code (C 1 ) from the master DEM circuit is encoded into parallel codes (C 2 ) with the same weighting for each code and corresponding to the configuration of the 3 or more output nodes on the basis of a prescribed DEM algorithm, and the obtained parallel codes are output in parallel from 3 or more output nodes.

CROSSTALK MITIGATION

This application describes methods and apparatus for mitigating the effects of crosstalk in multichannel audio. An audio driver circuit () for driving first and second audio loads () having a common return path (R), has first and second signal paths (Left and Right). A crosstalk compensation block () is configured to add a first compensation signal to the first signal path and add a second compensation signal to the second signal path. The first compensation signal is generated based on the second audio signal and a first compensation function and the second compensation signal is generated based on the first audio signal and a second compensation function. Each of the first and second compensation functions is based on a predetermined impedance value for at least part of the common return path (R) and is also based on a determined DC impedance value (Z, Z) for one of the first and second audio loads which is modified by a band correction factor (γ). The band correction factor modifies the DC impedance value so it is a better estimate of impedance across the frequency band of interest. 1. An audio driver circuit for driving first and second audio loads having a common return path , the circuit comprising:a first signal path for receiving a first audio signal and outputting a first driving signal for driving the first audio load;a second signal path for receiving a second audio signal and outputting a second driving signal for driving the second audio load;a crosstalk compensation block configured to add a first compensation signal to the first signal path and add a second compensation signal to the second signal path;the crosstalk compensation block being configured to generate the first compensation signal based on the second audio signal and a first compensation function and to generate the second compensation signal based on the first audio signal and a second compensation function;wherein each of the first and second compensation functions is based on a ...

CLASS D AMPLIFIER CIRCUIT

This application relates to Class D amplifier circuits (). A modulator () controls a Class D output stage () based on a modulator input signal (Dm) to generate an output signal (Vout) which is representative of an input signal (Din). An error block (), which may comprise an ADC (), generates an error signal (ε) from the output signal and the input signal. In various embodiments the extent to which the error signal (ε) contributes to the modulator input signal (Dm) is variable based on an indication of the amplitude of the input signal (Din). The error signal may be received at a first input () of a signal selector block (). The input signal may be received at a second input () of the signal selector block (). The signal selector block may be operable in first and second modes of operation, wherein in the first mode the modulator input signal is based at least in part on the error signal; and in the second mode the modulator input signal is based on the digital input signal and is independent of the error signal. The error signal can be used to reduce distortion at high signal levels but is not used at low signal levels and so the noise floor at low signal levels does not depend on the component of the error block (). 121.-. (canceled)22. A Class D amplifier circuit for receiving a digital input signal and outputting an analogue output signal comprising:a class-D output stage;a digital modulator for generating at least one control signal for controlling said class-D output stage based on a modulator input signal;an error block for generating an error signal, said error block comprising an analogue to digital converter for receiving an indication of said analogue output signal and a subtractor for generating said error signal based on the output of the analogue to digital converter and the digital input signal; a selector module;', 'a first signal path between a first input for receiving the error signal and the selector module; and', 'a second signal path between a ...

AMPLIFIER AND AMPLIFICATION METHOD

PROBLEM TO BE SOLVED: To provide an amplifier capable of increasing the upper limit of amplitude in a stereo signal generated between one common terminal and the output terminal of left and right channels without increasing a supply voltage. SOLUTION: The level of the common terminal C is changed according to the average of input audio signals ViL, ViR to increase the amplitude of output audio signals VL, VR, thus increasing the amplitude of the audio signals VL, VR to be supplied to headphones as compared with when the level of the common terminal C is kept constant. COPYRIGHT: (C)2007,JPO&INPIT ...

FRACTURING FLUID VISCOSITY-CONTROLLING AGENT TO BE USED IN HYDRAULIC FRACTURING

... [Problem] To provide: a fracturing fluid viscosity-controlling agent, which is capable of maintaining the high viscosity of the fracturing fluid during fracture formation in hydraulic fracturing and of reducing the viscosity during recovery of the fracturing fluid; a fracturing fluid comprising said viscosity-controlling agent; and a crude oil or natural gas drilling method using said fracturing fluid. [Solution] This viscosity-controlling agent, which is used for controlling viscosity changes of a fracturing fluid used in hydraulic fracturing, comprises polyalkylene oxide and a viscosity-reducing agent and is a tablet.

METHOD FOR PRODUCING MEDIUM-MOLECULAR-WEIGHT POLYALKYLENEOXIDE

A method for producing a medium-molecular weight polyalkylene oxide having a viscosity-average molecular weight of from 100,000 to 2,500,000, including heat-treating a polyalkylene oxide having a viscosity-average molecular weight of 3,000,000 or more at a temperature of from 30° to 70° C. in an aliphatic hydrocarbon solvent having a dissolved oxygen concentration of 0.5 mg/L or more, in the presence of a radical initiator in an amount of from 0.001 to 1 part by mass, based on 100 parts by mass of the polyalkylene oxide, and thereafter adding an antioxidant to a mixture in an amount of from 0.001 to 5 parts by mass, based on 100 parts by mass of the polyalkylene oxide to remove the solvent. According to the method of the present invention, a medium-molecular weight polyalkylene oxide having a viscosity-average molecular weight of from 100,000 to 2,500,000 which has excellent storage stability can be industrially obtained without subjecting to a gamma-ray irradiation treatment.

Method for producing medium-molecular-weight polyalkyleneoxide

Provided is a method for producing medium-molecular-weight polyalkyleneoxide having a viscosity-average molecular weight of 100,000 to 2,500,000, by subjecting polyalkyleneoxide having a viscosity-average molecular weight of 3,000,000 or more to heat treatment at 30 to 70 C in an aliphatic hydrocarbon solvent having a dissolved oxygen concentration of 0.5 mg/L or more, in the presence of 0.001 to 1 parts by mass of a radical generator with respect to 100 parts by mass of the polyalkyleneoxide, and thereafter adding 0.001 to 5 parts by mass of an antioxidant with respect to 100 parts by mass of the polyalkyleneoxide thereby removing the solvent. According to the method of the present invention, medium-molecular-weight polyalkyleneoxide having a viscosity-average molecular weight of 100,000 to 2,500,000 which has excellent storage stability can be industrially obtained without carrying out a gamma-irradiation treatment.

METHOD AND APPARATUS FOR FORMING TRANSIENT RESPONSE CHARACTERISTIC

PROBLEM TO BE SOLVED: To provide an apparatus for forming a transient response characteristic suitable for reducing a transient response error. SOLUTION: A transient response generating circuit A is provided with: a first circuit 3 for generating a transient response OUT1 in a first polarity direction; a second circuit 4 for generating a transient response OUT2 in a second polarity direction reverse to the first polarity; and a transient response composite circuit 6 for combining the first polarity direction transient response OUT1 with a second polarity direction transient response OUT2 to produce a composite transient response OUTC. COPYRIGHT: (C)2006,JPO&NCIPI ...

Class D amplifier circuit

Class-D Amplifier Circuits

Switching losses in a class-D audio amplifier are reduced by decreasing the switching frequency at low input signal amplitudes. The required minimum of the ratio of the switching frequency to the signal frequency for stable operation has been found to be lower at low signal amplitudes. The amplitude of the ramp or sawtooth waveform generated by circuit 302 is maintained invariant with frequency by altering the magnitude of the switched currents (figure 6) and/or integrating capacitors (figure 10) with respect to the selected switching frequency. Output signal transients caused by the frequency change may be reduced by using gradual and smooth frequency transitions (figure 9) and by changing frequency only at the peaks of the sawtooth waveform (figure 7). Where only discrete frequencies are available a sigma-delta modulator (1101, figure 11) may transition repeatedly between the frequencies to approximate the required smooth frequency transition. The loop filter bandwidth may be programmable ...

Fracturing fluid viscosity-controlling agent to be used in hydraulic fracturing

... [Problem] To provide: a fracturing fluid viscosity-controlling agent, which is capable of maintaining the high viscosity of the fracturing fluid during fracture formation in hydraulic fracturing and of reducing the viscosity during recovery of the fracturing fluid; a fracturing fluid comprising said viscosity-controlling agent; and a crude oil or natural gas drilling method using said fracturing fluid. [Solution] This viscosity-controlling agent, which is used for controlling viscosity changes of a fracturing fluid used in hydraulic fracturing, comprises polyalkylene oxide and a viscosity-reducing agent and is a tablet.

PWM DRIVER AND CLASS-D AMPLIFIER USING THE SAME

PROBLEM TO BE SOLVED: To provide a class-D amplifier in which generation of foldover noise is reduced. SOLUTION: A class-D amplifier comprises a D/A converter 10 which operates at a first sampling frequency, and a PWM driver which receives an output from the D/A converter 10. The PWM driver 3 operates at a second sampling frequency synchronized with the first sampling frequency. The second sampling frequency can be related to the triangular wave frequency of the PWM driver. Furthermore, the first sampling frequency and the second sampling frequency can be synchronized by relating these frequencies so that one frequency becomes an integer multiple of the other. COPYRIGHT: (C)2006,JPO&NCIPI ...

Signal processing for MEMS capacitive transducers

PAPERMAKING METHOD AND PAPERMAKING MACHINE

A papermaking method conducted using a papermaking machine which includes a pump (1), a screen (2) located downstream from the pump (1), and a head box (3) disposed downstream from the screen (2). Downstream from the pump (1), an aqueous papermaking thickener solution having a concentration of 0.1-3.0 wt.% is added to a feed pulp slurry from which impurities are to be removed with the screen (2). © KIPO & WIPO 2009 ...

Fracturing fluid viscosity-controlling agent to be used in hydraulic fracturing

... [Problem] To provide: a fracturing fluid viscosity-controlling agent, which is capable of maintaining the high viscosity of the fracturing fluid during fracture formation in hydraulic fracturing and of reducing the viscosity during recovery of the fracturing fluid; a fracturing fluid comprising said viscosity-controlling agent; and a crude oil or natural gas drilling method using said fracturing fluid. [Solution] This viscosity-controlling agent, which is used for controlling viscosity changes of a fracturing fluid used in hydraulic fracturing, comprises polyalkylene oxide and a viscosity-reducing agent and is a tablet.

CLASS D AMPLIFIERS

The present disclosure relates to Class D amplifier circuitry comprising: an input for receiving an input signal; first and second output nodes for driving a load connected between the first and second output nodes. A first driver stage is provided for switching the first node between a first supply rail and a second supply rail, and a second driver stage is provided for switching the second node between the first supply rail and the second supply rail. The Class D amplifier circuitry also includes first driver control circuitry configured to receive a first carrier wave and control the switching of the first driver stage based in part on the first carrier wave; second driver control circuitry configured to receive a second carrier wave and control the switching of the second driver stage based in part on the second carrier wave; and a carrier wave generator configured to provide the first carrier wave and the second carrier wave. A phase shift between the first carrier wave and the second ...

Signal processing for MEMS capacitive transducers

The circuitry processes sense signals generated by MEMS capacitive transducers, particularly microphones, to compensate for distortion in the sense signals, possibly due to large-value input signals. The circuitry has a signal path between an input 204 for receiving the sense signal and an output 205. Compensation circuitry 206, 207 is configured to monitor the signal at a first point along the signal path and generate a correction signal Scoff; and modify the signal at at least a second point along said signal path based on said correction signal. The correction signal is a function of the value of the signal at the first point so as to introduce compensation components into the output signal that compensate for distortion components in the sense signal. The first point may be before or after the second point. The monitoring may be performed in an analogue or a digital part of the signal path the modification may be applied in an analogue or a digital part of the signal path.

Class D amplifier circuit

WEIGHT LEVEL GENERATING METHOD AND DEVICE

A weight level generator is provided. Weight level generator W has plural weight generators 5 - 1 - 5 -j. At least one of said plural weight generators is used at at least two different time rates. Also, a digital-to-analog converter (DAC) using said weight generators is equipped with a digital signal source, a weight controller, and a weight generator.

Class D amplifiers

The present disclosure relates to Class D amplifier circuitry comprising: an input for receiving an input signal; first and second output nodes for driving a load connected between the first and second output nodes. A first driver stage is provided for switching the first node between a first supply rail and a second supply rail, and a second driver stage is provided for switching the second node between the first supply rail and the second supply rail. The Class D amplifier circuitry also includes first driver control circuitry configured to receive a first carrier wave and control the switching of the first driver stage based in part on the first carrier wave; second driver control circuitry configured to receive a second carrier wave and control the switching of the second driver stage based in part on the second carrier wave; and a carrier wave generator configured to provide the first carrier wave and the second carrier wave. A phase shift between the first carrier wave and the second ...

Class D amplifier circuit

A modulator 201 controls a Class D output stage 202 based on a modulator input signal Dm to generate an output signal Vout representative of digital input signal Din. The error block 205, which may comprise an ADC 207, generates an error signal E from the input and output signals, and the degree to which the error signal E contributes to the modulator input signal Dm depends on an indication of the amplitude of the input signal Din. The error signal E and the input signal Din are received at first and second inputs 204,206 of a block 203. The error signal is filtered by a loop filter 211, scaled by a variable multiplier 213, then added to the input signal Din. The multiplier 213 scales the feedback signal in dependence on the detected envelope of the input signal. The feedback reduces distortion at high signal levels but is reduced or disabled at low signal levels so that the noise floor depends less on the components of the error block 205 or is independent of these components.

Class D amplifier circuit

A modulator 201 controls a Class D output stage 202 based on a modulator input signal Dm. An error block 205, which may comprise a feedback ADC 207, generates an error signal from the output signal and the input signal Din. At high signal amplitudes the modulator input signal is based at least in part on the error signal, but at low signal amplitudes the modulator input signal is based only on the digital input signal. Distortion at high signal levels is reduced by feedback, while noise generated in the feedback ADC 207 has no effect at low signal levels. The noise performance requirement of the ADC may be relaxed, allowing use of a smaller ADC using less power.

Papermaking method and papermaking machine

A papermaking method conducted using a papermaking machine which includes a pump (1), a screen (2) located downstream from the pump (1), and a head box (3) disposed downstream from the screen (2). Downstream from the pump (1), an aqueous papermaking thickener solution having a concentration of 0.1-3.0 wt.% is added to a feed pulp slurry from which impurities are to be removed with the screen (2).

Pulse-width modulation

This application relates to digital PWM modulation. A PWM modulator (400, 1100) has a PWM generator (402) configured to receive pulse width data (PWidth) and to output a PWM signal (SPWM) comprising a plurality of repeating PWM cycle periods, in which the duration of any pulse of the PWM signal in each PWM cycle period is based on the pulse width data. The PWM generator is configured to synchronise the PWM cycle periods, and the start and end of any PWM pulse, to a received first clock signal. The PWM generator is operable to generate pulses that have a positional error from a centred position within the PWM cycle period and a pulse position controller (403) is configured to control the position of a pulse in a PWM cycle period so as to at least partly compensate for the positional error of one or more preceding pulses.

Fracturing fluid viscosity-controlling agent to be used in hydraulic fracturing

A fracturing fluid viscosity-controlling agent maintains the high viscosity of the fracturing fluid during fracture formation in hydraulic fracturing and reduces the viscosity during recovery of the fracturing fluid. A fracturing fluid which includes the viscosity-controlling agent is provided as well as a crude oil or natural gas drilling method using the fracturing fluid with the viscosity-controlling agent. This viscosity-controlling agent contains polyalkylene oxide and a viscosity-reducing agent and is in the form of a tablet.

Class-D amplifier circuits

Methods and apparatus for Class-D amplifier circuits with improved power efficiency. The circuit has an output stage with at least first and second switches and a modulator that receives an input signal to be amplified, SIN, and a first clock signal fSW. The modulator controls the duty cycles of the first and second switches, within a switching cycle based on the input signal, wherein the switching cycle has a switching frequency based on the first clock signal. A frequency controller controls the frequency of the first clock signal in response to an indication of the amplitude of the input signal so as to provide a first switching frequency at a first input signal amplitude and a second, lower, switching frequency at a second, lower, input signal amplitude. A lower switching frequency can be tolerated at low signal amplitudes and varying the switching frequency in this way thus maintains stability whilst reducing switching power losses.

Water-soluble metal working oil agent

... [Problem] To provide: a water-soluble metal working oil agent which can be prevented from being scattered in the form of mists for a long period when used for the cutting processing, grinding processing and the like of metallic materials; and a method for producing the water-soluble metal working oil agent. [Solution] The water-soluble metal working oil agent according to the present invention comprises a polyalkylene oxide having a weight average molecular weight of 100,000 to 1,000,000 and water.

Polyalkylene oxide particles and method for producing the same

This invention is related to a method for producing polyalkylene oxide particles, including a step of polymerizing a polyalkylene oxide to form polyalkylene oxide particles in a polymerization solution containing a polymerization solvent and catalysts dispersed in the polymerization solvent. An average particle size of the catalysts is 25 m or less.

D-class amplifier

A D-class amplifier that can suppress noise generated when a D-class amplification operation is started/stopped. When a D-class amplification operation is started/stopped, the pulse widths and pulse interval of output signals Pout1, Pout2 are gradually changed, so it is possible to prevent a large variation in the signal fed as a differential signal of output signals Pout1, Pout2 to the load, and it is possible to reduce noise. That is, by gradually changing the pulse interval while keeping the pulse widths of output signals Pout1, Pout2 constant, it is possible to suppress variation in the relatively high frequency component corresponding to the component of the pulse signal. Also, by gradually changing the widths of output signals Pout1, Pout2 while keeping the pulse interval constant, it is possible to suppress variation in the relatively low frequency component corresponding to the average value of the pulse signal.

CLASS-D AMPLIFIER CIRCUITS

Methods and apparatus for Class-D amplifier circuits with improved power efficiency. The circuit has an output stage with at least first and second switches and a modulator that receives an input signal to be amplified, S, and a first clock signal f. The modulator controls the duty cycles of the first and second switches, within a switching cycle based on the input signal, wherein the switching cycle has a switching frequency based on the first clock signal. A frequency controller controls the frequency of the first clock signal in response to an indication of the amplitude of the input signal so as to provide a first switching frequency at a first input signal amplitude and a second, lower, switching frequency at a second, lower, input signal amplitude. A lower switching frequency can be tolerated at low signal amplitudes and varying the switching frequency in this way thus maintains stability whilst reducing switching power losses. 1. A Class-D amplifier circuit for amplifying an input signal comprising:an output stage comprising at least first and second switches;a modulator comprising a signal input for receiving said input signal and a clock input for receiving a first clock signal, the modulator being configured to generate a switch control signal to control the duty cycles of said first and second switches within a switching cycle based on said input signal, wherein said switching cycle has a switching frequency based on said first clock signal; anda frequency controller configured to control the frequency of said first clock signal based on said switch control signal.2. A Class-D amplifier circuit as claimed in claim 1 , wherein the frequency controller is configured to control the frequency of said first clock signal so as to provide a first switching frequency at a first value of duty cycle of said first and second switches and a second switching frequency at a second value of duty cycle of said first and second switches claim 1 , wherein said second value ...

POLYALKYLENE OXIDE COMPOSITION

An aqueous solution and an aqueous dispersion of a composition that contains a polyalkylene oxide, a phenolic antioxidant and a sulfur-containing amine compound are less likely to impair the stability of the polyalkylene oxide even in the case of containing an alkali. In the above composition, the content of each of the phenolic antioxidant and the sulfur-containing amine compound is preferably set to 0.001 to 5 parts by mass based on 100 parts by mass of the polyalkylene oxide, and the ratio of the sulfur-containing amine compound relative to 100 parts by mass of the phenolic antioxidant is preferably set to 20 to 200 parts by mass.

Class D amplifier circuit

This application relates to Class D amplifier circuits. A modulator controls a Class D output stage based on a modulator input signal (Dm) to generate an output signal (Vout) which is representative of an input signal (Din). An error block, which may comprise an ADC, generates an error signal (ε) from the output signal and the input signal. In various embodiments the extent to which the error signal (ε) contributes to the modulator input signal (Dm) is variable based on an indication of the amplitude of the input signal (Din). The error signal may be received at a first input of a signal selector block. The input signal may be received at a second input of the signal selector block. The signal selector block may be operable in first and second modes of operation, wherein in the first mode the modulator input signal is based at least in part on the error signal; and in the second mode the modulator input signal is based on the digital input signal and is independent of the error signal.

Friction resistance reducing agent and fire-extinguishing agent

本發明係提供在使對水性介質等的降低摩擦阻力之效果上優異的摩擦阻力降低劑，及含有該摩擦阻力降低劑之滅火劑。 本發明摩擦阻力降低劑含有聚環氧烷水性分散液，該聚環氧烷水性分散液含有聚環氧烷、氧化鋁、電解質及水，且前述聚環氧烷是分散在該聚環氧烷水性分散液。依據上述摩擦阻力降低劑，在使對水性介質等的降低摩擦阻力之效果上是優異的。

PULSE-WIDTH MODULATION

This application relates to digital PWM modulation. A PWM modulator ( 400, 1100 ) has a PWM generator ( 402 ) configured to receive pulse width data (P Width ) and to output a PWM signal (S PWM ) comprising a plurality of repeating PWM cycle periods, in which the duration of any pulse of the PWM signal in each PWM cycle period is based on the pulse width data. The PWM generator is configured to synchronise the PWM cycle periods, and the start and end of any PWM pulse, to a received first clock signal. The PWM generator is operable to generate pulses that have a positional error from a centred position within the PWM cycle period and a pulse position controller ( 403 ) is configured to control the position of a pulse in a PWM cycle period so as to at least partly compensate for the positional error of one or more preceding pulses.

DYNAMIC ELEMENT MATCHING METHOD AND DEVICE

The invention provides an improved dynamic element matching (DEM) device. The DEM device performs dynamic element matching processing at a second timing rate different from the first timing rate for the digital input. As an embodiment, the DEM device is composed of encoder 10 and feedback circuit 12 . Said encoder 10 has two inputs and one output. Of the two inputs, one receives the digital input as the object for the DEM processing, and the other input receives the output of feedback circuit 12 . Then, the digital output of the encoded result is generated. Said feedback circuit 12 has sampling rate converter 120 and loop filter 122 in order to perform DEM processing at a timing rate different from the timing rate for the digital input as the DEM processing object.

WATER ABSORBENT RESIN DISPERSION LIQUID, WATER ABSORBENT RESIN COATING FILM AND METHOD FOR PRODUCING SAME

Provided is a water-absorbent resin dispersion that is capable of maintaining the dispersibility of a water-absorbent resin more readily than conventional dispersions. 1. A water-absorbent resin dispersion comprising a water-absorbent resin , a thickener , and an organic solvent , the thickener being dissolved in the organic solvent , the water-absorbent resin being dispersed in the organic solvent.2. The water-absorbent resin dispersion according to claim 1 , wherein the organic solvent is at least one member selected from the group consisting of Calcohol compounds claim 1 , benzene claim 1 , toluene claim 1 , xylene claim 1 , ethylene carbonate claim 1 , propylene carbonate claim 1 , tetrahydrofuran claim 1 , 1 claim 1 ,4-dioxane claim 1 , acetone claim 1 , methyl ethyl ketone claim 1 , acetonitrile claim 1 , 1 claim 1 ,2-dichloroethane claim 1 , chloroform claim 1 , and dimethylformamide.3. The water-absorbent resin dispersion according to claim 1 , wherein the thickener is present in an amount of 0.5 to 50 parts by mass claim 1 , per 100 parts by mass of the organic solvent.4. The water-absorbent resin dispersion according to claim 1 , wherein the water-absorbent resin is present in an amount of 5 to 50 parts by mass claim 1 , per 100 parts by mass of the organic solvent.5. The water-absorbent resin dispersion according to claim 1 , wherein the thickener has a viscosity of 200 to 10000 mPa·s when dissolved in the organic solvent.6. A water-absorbent resin coating film comprising the water-absorbent resin dispersion according to that is dried.7. A method for producing a water-absorbent resin coating film claim 1 , comprising drying the water-absorbent resin dispersion according to to form a coating film. The present invention relates to a water-absorbent resin dispersion, a water-absorbent resin coating film, and a method for producing the film.In recent years, water-absorbent resins have been widely used in various fields, including hygienic materials such as ...

CLASS D AMPLIFIERS

The present disclosure relates to Class D amplifier circuitry comprising: an input for receiving an input signal; first and second output nodes for driving a load connected between the first and second output nodes. A first driver stage is provided for switching the first node between a first supply rail and a second supply rail, and a second driver stage is provided for switching the second node between the first supply rail and the second supply rail. The Class D amplifier circuitry also includes first driver control circuitry configured to receive a first carrier wave and control the switching of the first driver stage based in part on the first carrier wave; second driver control circuitry configured to receive a second carrier wave and control the switching of the second driver stage based in part on the second carrier wave; and a carrier wave generator configured to provide the first carrier wave and the second carrier wave. A phase shift between the first carrier wave and the second carrier wave is adjustable responsive to a mode control signal.

Crosstalk mitigation

This application describes methods and apparatus for mitigating the effects of crosstalk in multichannel audio. An audio driver circuit (200) for driving first and second audio loads (103) having a common return path (RC), has first and second signal paths (Left and Right). A crosstalk compensation block (205) is configured to add a first compensation signal to the first signal path and add a second compensation signal to the second signal path. The first compensation signal is generated based on the second audio signal and a first compensation function and the second compensation signal is generated based on the first audio signal and a second compensation function. Each of the first and second compensation functions is based on a predetermined impedance value for at least part of the common return path (RH1) and is also based on a determined DC impedance value (ZL, ZR) for one of the first and second audio loads which is modified by a band correction factor (γ). The band correction factor ...

METHOD AND APPARATUS FOR GENERATING WEIGHT LEVEL

PROBLEM TO BE SOLVED: To increase the number of weight levels by using at least a weight generator in at least two different time rates. SOLUTION: The weight level generator W is provided with a plurality of weight level generators 5-1 to 5-j, and uses at least one of the weight generators in at least two different time rates. Further, a digital-analog converter (DAC) employing such weight generators is provided with a digital signal source, a weight controller, and a weight generator. COPYRIGHT: (C)2008,JPO&INPIT ...

Method for producing medium-molecular-weight polyalkyleneoxide

本發明係一種黏度平均分子量為100,000~2,500,000之中分子量聚氧化伸烷之製造方法，其係於溶氧濃度為0.5mg/L以上之脂肪族烴溶劑中，相對於聚氧化伸烷100質量份而於0.001~1質量份之自由基產生劑之存在下，於30~70℃下對黏度平均分子量300萬以上之聚氧化伸烷進行加熱處理後，相對於聚氧化伸烷100質量份而添加0.001~5質量份之抗氧化劑後去除溶劑。藉由本發明之方法，無需進行伽馬射線照射處理，而可自工業途徑獲得保存穩定性優異之黏度平均分子量10萬~250萬之中分子量聚氧化伸烷。

DETECTION OF LIVE SPEECH

A method of detecting live speech comprises: receiving a signal containing speech; obtaining a first component of the received signal in a first frequency band, wherein the first frequency band includes audio frequencies; and obtaining a second component of the received signal in a second frequency band higher than the first frequency band. Then, modulation of the first component of the received signal is detected; modulation of the second component of the received signal is detected; and the modulation of the first component of the received signal and the modulation of the second component of the received signal are compared. It may then be determined that the speech may not be live speech, if the modulation of the first component of the received signal differs from the modulation of the second component of the received signal. 1. A method of detecting live speech , the method comprising:receiving a signal containing speech;obtaining a first component of the received signal in a first frequency band, wherein the first frequency band includes audio frequencies;obtaining a second component of the received signal in a second frequency band higher than said first frequency band;detecting modulation of the first component of the received signal;detecting modulation of the second component of the received signal;comparing the modulation of the first component of the received signal and the modulation of the second component of the received signal; anddetermining whether the speech is live speech, depending on a result of comparing the modulation of the first component of the received signal and the modulation of the second component of the received signal.2. A method according to claim 1 , wherein obtaining the first component of the received signal comprises low-pass filtering the received signal.3. A method according to claim 1 , wherein obtaining the second component of the received signal comprises high-pass filtering the received signal.4. A method according to ...

Papermaking method and papermaking machine

Alkylene oxide polymer production method

Provided is an alkylene oxide polymer production method, whereby it becomes possible to produce an alkylene oxide polymer having a high polymerization degree on an industrial scale and with high reproducibility. An alkylene oxide polymer production method comprising carrying out a polymerization reaction of an alkylene oxide in an inert hydrocarbon solvent in the presence of a zinc catalyst to produce an alkylene oxide polymer, wherein the zinc catalyst is produced by reacting an organozinc compound with a monohydric alcohol in an amount of 12-fold equivalent or less relative to the amount of the organozinc compound and an aliphatic polyhydric alcohol in an amount of 0.2- to 1.1-fold equivalent relative to the amount of the organozinc compound, and the polymerization reaction is carried out under such a condition that the amount of the monohydric alcohol in the polymerization reaction system becomes 0.01-fold equivalent or less relative to the amount of the organozinc compound.

Dynamic element matching method and device

The invention provides an improved dynamic element matching (DEM) device. The DEM device performs dynamic element matching processing at a second timing rate different from the first timing rate for the digital input. As an embodiment, the DEM device is composed of encoder 10 and feedback circuit 12. Said encoder 10 has two inputs and one output. Of the two inputs, one receives the digital input as the object for the DEM processing, and the other input receives the output of feedback circuit 12. Then, the digital output of the encoded result is generated. Said feedback circuit 12 has sampling rate converter 120 and loop filter 122 in order to perform DEM processing at a timing rate different from the timing rate for the digital input as the DEM processing object.

Pulse-width modulation

This application relates to digital PWM modulation. A PWM modulator (400, 1100) has a PWM generator (402) configured to receive pulse width data (PWidth) and to output a PWM signal (SPWM) comprising a plurality of repeating PWM cycle periods, in which the duration of any pulse of the PWM signal in each PWM cycle period is based on the pulse width data. The PWM generator is configured to synchronise the PWM cycle periods, and the start and end of any PWM pulse, to a received first clock signal. The PWM generator is operable to generate pulses that have a positional error from a centred position within the PWM cycle period and a pulse position controller (403) is configured to control the position of a pulse in a PWM cycle period so as to at least partly compensate for the positional error of one or more preceding pulses.

PULSE-WIDTH MODULATION

This application relates to digital PWM modulation. A PWM modulator () has a PWM generator () configured to receive pulse width data (P) and to output a PWM signal (S) comprising a plurality of repeating PWM cycle periods, in which the duration of any pulse of the PWM signal in each PWM cycle period is based on the pulse width data. The PWM generator is configured to synchronise the PWM cycle periods, and the start and end of any PWM pulse, to a received first clock signal. The PWM generator is operable to generate pulses that have a positional error from a centred position within the PWM cycle period and a pulse position controller () is configured to control the position of a pulse in a PWM cycle period so as to at least partly compensate for the positional error of one or more preceding pulses. 1. A PWM (pulse-width-modulation) modulator comprising:a PWM generator configured to receive pulse width data and to output a PWM signal comprising a plurality of repeating PWM cycle periods, in which the duration of any pulse of the PWM signal in each PWM cycle period is based on the pulse width data,wherein the PWM generator is configured to receive a first clock signal and to synchronise the PWM cycle periods and the start and end of any pulse of the PWM signal to the first clock signal;wherein the PWM generator is operable to generate pulses that have a positional error from a centred position within the PWM cycle period; andwherein the pulse-width modulator comprises a pulse position controller configured to control the position of a pulse in a PWM cycle period so as to at least partly compensate for the positional error of one or more preceding pulses.2. A PWM modulator as claimed in wherein the pulse position controller is configured to receive the pulse width data and comprises:an error block for determining a positional error for a pulse based on the pulse width data;a loop filter for filtering the positional error; anda quantizer configured to output pulse ...

CLASS D AMPLIFIER CIRCUIT

This application relates to Class D amplifier circuits. A modulator controls a Class D output stage based on a modulator input signal (Dm) to generate an output signal (Vout) which is representative of an input signal (Din). An error block, which may comprise an ADC, generates an error signal (ε) from the output signal and the input signal. In various embodiments the extent to which the error signal (ε) contributes to the modulator input signal (Dm) is variable based on an indication of the amplitude of the input signal (Din). The error signal may be received at a first input of a signal selector block. The input signal may be received at a second input of the signal selector block. The signal selector block may be operable in first and second modes of operation, wherein in the first mode the modulator input signal is based at least in part on the error signal; and in the second mode the modulator input signal is based on the digital input signal and is independent of the error signal. The error signal can be used to reduce distortion at high signal levels but is not used at low signal levels and so the noise floor at low signal levels does not depend on the component of the error block. 1. A Class-D amplifier circuit for amplifying an input signal comprising:a controller configured to control the Class-D amplifier circuit to selectively transition between an open-loop operational mode and a closed-loop operational mode based on indication of amplitude of said input signal;a class-D output stage;a modulator for generating at least one control signal for controlling switching of a said class-D output stage wherein the controller comprises a signal selector configured such that in the closed-loop operational mode an input to the modulator is based on the input signal combined with a feedback signal and in the open-loop operational mode the input to the modulator is based on the input signal with no contribution from the feedback signal; andan error block for ...

Digital encoder and digital-to-analog converter using same

A digital encoder having a dynamic element matching (DEM) processor is divided into a master DEM circuit and N slave DEM circuits. The master DEM circuit encodes a multibit digital input signal (INO) into parallel codes (C 1 ) corresponding to the coefficient of a plurality of output nodes on the basis of a prescribed DEM algorithm. Each of the N slave DEM means ( 2 ) has 3 or more output nodes. Code (C 1 ) from the master DEM circuit is encoded into parallel codes (C 2 ) with the same weighting for each code and corresponding to the configuration of the 3 or more output nodes on the basis of a prescribed DEM algorithm, and the obtained parallel codes are output in parallel from 3 or more output nodes.

DIGITAL ENCODER AND D/A CONVERTER USING THE SAME

PROBLEM TO BE SOLVED: To relieve the tradeoff between a mounting area and noise suppression performance, and to propose a configuration for increasing the degree of freedom in design to increase the noise suppression performance while suppressing the mounting area for a digital encoder. SOLUTION: A dynamic element matching (DEM) processing means is divided into a master DEM means 1 and N slave DEM means 2. The master DEM means 1 encodes a multibit digital input signal IN0 to a parallel code C1 corresponding to the array of a plurality of output nodes, based on a prescribed DEM algorithm. The N slave DEM means 2 have at least three output codes each. A code C1 from the master DEM means 1 is encoded to a parallel code C2 in which weighting is the same in each code corresponding to the array of at least three output nodes, based on a prescribed DEM algorithm before outputting in parallel from at least three output nodes. COPYRIGHT: (C)2006,JPO&NCIPI ...

COMPUTING CIRCUITRY

This application relates to computing circuitry () for analogue computing. A plurality of current generators () are each configured to generate a defined current (I, I, . . . I) based on a respective input data value (D, D, . . . D). A memory array (), having at least one set () of programmable-resistance memory cells (), is arranged to receive the defined currents from each of the current generators at a respective signal line (). Each set () of programmable-resistance memory cells () includes a memory cell associated with each signal line that, in use, can be connected between the relevant signal line and a reference voltage so as to generate a voltage on the signal line. An adder module () is coupled to each of the signal lines to generate a voltage at an output node () based on the sum of the voltages on each of the signal lines. 1. Computing circuitry comprising:a plurality of current generators, each current generator being configured to generate a defined current based on a respective input data value;a memory array configured to, in use, receive the defined current from each of the current generators at a respective signal line, wherein the memory array comprises at least one set of programmable-resistance memory cells, wherein a set of programmable-resistance memory cells comprises a memory cell associated with each signal line that, in use, can be connected between the relevant signal line and a reference voltage so as to generate a voltage on the signal line;an adder module coupled to each of said signal lines to generate a voltage at an output node based on the sum of the voltages on each of the signal lines.2. Computing circuitry as claimed in wherein the memory array comprises a plurality of sets of programmable-resistance memory cells that can be individually selected to receive the defined currents from the current generators.3. Computing circuitry as claimed in wherein the computing circuitry is configured to operate in a sequence of computing ...

Polyalkylene oxide particles and production method for the same

The present invention relates to a production method of polyalkylene oxide particles including a step of forming the polyalkylene oxide particles by polymerization of an alkylene oxide in a polymerization solution containing a polymerization solvent and a catalyst dispersed in the polymerization solvent. The average particle diameter of the catalyst is more than 25 μm.

CLASS-D AMPLIFIER CIRCUITS

Methods and apparatus for Class-D amplifier circuits with improved power efficiency. The circuit has an output stage with at least first and second switches and a modulator that receives an input signal to be amplified, S, and a first clock signal f. The modulator controls the duty cycles of the first and second switches, within a switching cycle based on the input signal, wherein the switching cycle has a switching frequency based on the first clock signal. A frequency controller controls the frequency of the first clock signal in response to an indication of the amplitude of the input signal so as to provide a first switching frequency at a first input signal amplitude and a second, lower, switching frequency at a second, lower, input signal amplitude. A lower switching frequency can be tolerated at low signal amplitudes and varying the switching frequency in this way thus maintains stability whilst reducing switching power losses. 1. A Class-D amplifier circuit for amplifying an input signal comprising:an output stage comprising at least first and second switches;a modulator comprising a signal input for receiving said input signal and a clock input for receiving a first clock signal, the modulator being configured to control the duty cycles of said first and second switches within a switching cycle based on said input signal, wherein said switching cycle has a switching frequency based on said first clock signal; anda frequency controller for controlling the frequency of said first clock signal in response to an indication of the amplitude of the input signal so as to provide a first switching frequency at a first input signal amplitude and a second, lower, switching frequency at a second, lower, input signal amplitude.2. A class-D amplifier circuit as claimed in wherein said frequency controller comprises a comparator for comparing said indication of signal amplitude to at least one threshold and wherein said frequency controller is configured to control the ...

Polyalkylene oxide particles and method for producing the same

Class D amplifier circuit

This application relates to Class D amplifier circuits (200). A modulator (201) controls a Class D output stage (202) based on a modulator input signal (Dm) to generate an output signal (Vout) which is representative of an input signal (Din). An error block (205), which may comprise an ADC (207), generates an error signal (ε) from the output signal and the input signal. In various embodiments the extent to which the error signal (ε) contributes to the modulator input signal (Dm) is variable based on an indication of the amplitude of the input signal (Din). The error signal may be received at a first input (204) of a signal selector block (203). The input signal may be received at a second input (206) of the signal selector block (203). The signal selector block may be operable in first and second modes of operation, wherein in the first mode the modulator input signal is based at least in part on the error signal; and in the second mode the modulator input signal is based on the digital ...

PWM driver and class D amplifier using same

The objective of the invention is to provide a class D amplifier that can reduce aliasing noise. The class D amplifier has D/A converter 10 that operates at the first sampling frequency, and PWM driver 3 that receives the output from D/A converter 10 . Said PWM driver 3 operates at the second sampling frequency synchronized to the first sampling frequency. The second sampling frequency can be correlated to the delta wave frequency of the PWM driver. Also, synchronization of said first sampling frequency and said second sampling frequency can be carried out with one of said frequencies being an integer multiple of the other.

SIGNAL PROCESSING FOR MEMS CAPACITIVE TRANSDUCERS

This application relates to circuitry for processing sense signals generated by MEMS capacitive transducers for compensating for distortion in such sense signals. The circuitry has a signal path between an input () for receiving the sense signal and an output () for outputting an output signal based on said sense signal. Compensation circuitry () is configured to monitor the signal at a first point along the signal path and generate a correction signal (Scorr); and modify the signal at at least a second point along said signal path based on said correction signal. The correction signal is generated as a function of the value of the signal at the first point along the signal path so as to introduce compensation components into the output signal that compensate for distortion components in the sense signal. The first point in the signal path may be before or after the second point in the signal path. The monitoring may be performed in an analogue or a digital part of the signal path and in either case the modification may be applied in an analogue or a digital part of the signal path. 154-. (canceled)55. A signal processing circuit for a MEMS capacitive transducer , the transducer producing , in use when biased by a bias voltage , a sense signal in response to an input stimulus , the signal processing circuit comprising:a signal path between an input for receiving said sense signal and an output for outputting an output signal based on said sense signal; and monitor the signal at a first point along the signal path and generate a correction signal; and', 'modify the signal at at least a second point along said signal path based on said correction signal;', 'wherein said correction signal is generated as a function of the instantaneous value of the signal at the first point along the signal path so as to introduce compensation components into the output signal that compensate for distortion components present in the sense signal at a given bias voltage., 'compensation ...

D-CLASS AMPLIFIER

A D-class amplifier that can suppress noise generated when a D-class amplification operation is started/stopped. When a D-class amplification operation is started/stopped, the pulse widths and pulse interval of output signals Pout1, Pout2 are gradually changed, so it is possible to prevent a large variation in the signal fed as a differential signal of output signals Pout1, Pout2 to the load, and it is possible to reduce noise. That is, by gradually changing the pulse interval while keeping the pulse widths of output signals Pout1, Pout2 constant, it is possible to suppress variation in the relatively high frequency component corresponding to the component of the pulse signal. Also, by gradually changing the widths of output signals Pout1, Pout2 while keeping the pulse interval constant, it is possible to suppress variation in the relatively low frequency component corresponding to the average value of the pulse signal.

Alkylene oxide polymer production method

Provided is a method to produce an alkylene oxide polymer having a high polymerization degree on an industrial scale and with high reproducibility. The method includes the step of carrying out a polymerization reaction of an alkylene oxide in an inert hydrocarbon solvent in the presence of a zinc catalyst to produce an alkylene oxide polymer. The zinc catalyst is produced by reaction of an organozinc compound with a monohydric alcohol in an amount of 12-fold equivalent or less relative to the amount of the organozinc compound and an aliphatic polyhydric alcohol in an amount of 0.2- to 1.1-fold equivalent relative to the amount of the organozinc compound. The polymerization reaction is carried out under such a condition that the amount of the monohydric alcohol in the polymerization reaction system becomes 0.01-fold equivalent or less relative to the amount of the organozinc compound.

ALKYLENE OXIDE POLYMER PRODUCTION METHOD

Provided is a method to produce an alkylene oxide polymer having a high polymerization degree on an industrial scale and with high reproducibility. The method includes the step of carrying out a polymerization reaction of an alkylene oxide in an inert hydrocarbon solvent in the presence of a zinc catalyst to produce an alkylene oxide polymer. The zinc catalyst is produced by reaction of an organozinc compound with a monohydric alcohol in an amount of 12-fold equivalent or less relative to the amount of the organozinc compound and an aliphatic polyhydric alcohol in an amount of 0.2- to 1.1-fold equivalent relative to the amount of the organozinc compound. The polymerization reaction is carried out under such a condition that the amount of the monohydric alcohol in the polymerization reaction system becomes 0.01-fold equivalent or less relative to the amount of the organozinc compound. 1. A method for the production of an alkylene oxide polymer comprising polymerizing an alkylene oxide in the presence of a zinc catalyst in an inert hydrocarbon solvent to produce an alkylene oxide polymer , wherein the method comprises:(a) preparing a zinc catalyst by reacting an organozinc compound with a monohydric alcohol in an amount of 12 equivalents or less relative to the organozinc compound and an aliphatic polyhydric alcohol in an amount of 0.2 to 1.1 equivalents relative to the organozinc compound,(b) distilling the zinc catalyst obtained by step (a) at a temperature not exceeding 100° C. such that the amount of the monohydric alcohol in the polymerization reaction is 0.01 equivalents or less relative to the organozinc compound, and(c) polymerizing the alklyene oxide in the presence of the zinc catalyst in which the amount of the monohydric alcohol has been adjusted to 0.01 equivalents or less relative to the organozinc compound.2. The method for the production of an alkylene oxide polymer according to claim 1 , wherein the organozinc compound is a dialkylzinc.3. The method ...

Class D amplifier circuit

This application relates to Class D amplifier circuits (200). A modulator (201) controls a Class D output stage (202) based on a modulator input signal (Dm) to generate an output signal (Vout) which is representative of an input signal (Din). An error block (205), which may comprise an ADC (207), generates an error signal (ε) from the output signal and the input signal. In various embodiments the extent to which the error signal (ε) contributes to the modulator input signal (Dm) is variable based on an indication of the amplitude of the input signal (Din). The error signal may be received at a first input (204) of a signal selector block (203). The input signal may be received at a second input (206) of the signal selector block (203). The signal selector block may be operable in first and second modes of operation, wherein in the first mode the modulator input signal is based at least in part on the error signal; and in the second mode the modulator input signal is based on the digital ...

AUDIO AMPLIFIERS

This application relates to methods and apparatus for amplification of audio signals with improved audio performance. An audio driving circuit ( 200 ) has an amplifier module ( 102 ) in a forward signal path between an input ( 103 ) for receiving an input audio signal (S IN ) and an output for outputting an audio driving signal (V OUT ). A pre-distortion module ( 202 ) is operable to apply a first transfer function to the signal in the forward signal path upstream of the amplifier module, wherein the first transfer function comprises a non-linear distortion function based on at least one distortion setting. An error block ( 203 ) is arranged to receive a first signal (S FF ) derived from the input signal and a second signal (S FB ) indicative of the voltage of the audio driving signal and determine a first error signal (ε 1 ) indicative of a difference between the first and second signals. The pre-distortion module ( 202 ) is operable to control the distortion setting(s) based on the first error signal.

Class D amplifier circuit

This application relates to Class D amplifier circuits (200). A modulator (201) controls a Class D output stage (202) based on a modulator input signal (Dm) to generate an output signal (Vout) which is representative of an input signal (Din). An error block (205), which may comprise an ADC (207), generates an error signal (ε) from the output signal and the input signal. In various embodiments the extent to which the error signal (ε) contributes to the modulator input signal (Dm) is variable based on an indication of the amplitude of the input signal (Din). The error signal may be received at a first input (204) of a signal selector block (203). The input signal may be received at a second input (206) of the signal selector block (203). The signal selector block may be operable in first and second modes of operation, wherein in the first mode the modulator input signal is based at least in part on the error signal; and in the second mode the modulator input signal is based on the digital ...

POLYALKYLENE OXIDE PARTICLES AND PRODUCTION METHOD FOR THE SAME

The present invention relates to a production method of polyalkylene oxide particles including a step of forming the polyalkylene oxide particles by polymerization of an alkylene oxide in a polymerization solution containing a polymerization solvent and a catalyst dispersed in the polymerization solvent. The average particle diameter of the catalyst is 25 μm or less. 1. A production method of polyalkylene oxide particles , comprising:forming polyalkylene oxide particles by polymerization of an alkylene oxide in a polymerization solution containing a polymerization solvent and a catalyst dispersed in the polymerization solvent,wherein the average particle diameter of the catalyst is 25 μm or less.2. The production method according to claim 1 ,wherein the catalyst is an organozinc catalyst.3. The production method according to claim 2 ,wherein the organozinc catalyst is a particulate reaction product obtainable by a method including: reacting an organozinc compound with an aliphatic polyhydric alcohol and a monohydric alcohol, thereby forming a particulate reaction product.4. The production method according to claim 1 ,wherein the polymerization solution contains 0.00005 mol or more of the catalyst with respect to 1 mol of the alkylene oxide.5. Polyalkylene oxide particles obtainable by the production method according to claim 1 , comprising:10% by mass or more of particles having a particle diameter of less than 150. The present invention relates to polyalkylene oxide particles and a production method for the same.A polyalkylene oxide is water-soluble and thermoplastic, therefore, the polyalkylene oxide is used for uses such as a viscous agent for papermaking, a ceramic binder, a polymerization stability assistant and a material for a pharmaceutical preparation. When the polyalkylene oxide is used as a thickener such as a viscous papermaking and the like, generally, the polyalkylene oxide having a high molecular weight is preferable from the viewpoint of a viscosity ...

Weight level generating method and device utilizing plural weights at different time rates

A weight level generator is provided. Weight level generator W has plural weight generators 5 - 1 - 5 - j. At least one of said plural weight generators is used at at least two different time rates. Also, a digital-to-analog converter (DAC) using said weight generators is equipped with a digital signal source, a weight controller, and a weight generator.

Polyalkylene oxide particles and method for producing the same

Method and apparatus for forming transient response characteristics

Transient response generating circuit A has a first circuit 3 that generates transient response OUT 1 in a first polarity direction, a second circuit 4 that generates transient response OUT 2 in a second polarity direction opposite to the first polarity, and a transient response synthesizing circuit 6 that combines the transient response OUT 1 in the first polarity direction and the transient response OUT 2 in the second polarity direction to generate composite transient response OUTC.

Class-D amplifier circuits

Methods and apparatus for Class-D amplifier circuits with improved power efficiency. The circuit has an output stage with at least first and second switches and a modulator that receives an input signal to be amplified, SIN, and a first clock signal fSW. The modulator controls the duty cycles of the first and second switches, within a switching cycle based on the input signal, wherein the switching cycle has a switching frequency based on the first clock signal. A frequency controller controls the frequency of the first clock signal in response to an indication of the amplitude of the input signal so as to provide a first switching frequency at a first input signal amplitude and a second, lower, switching frequency at a second, lower, input signal amplitude. A lower switching frequency can be tolerated at low signal amplitudes and varying the switching frequency in this way thus maintains stability whilst reducing switching power losses.

Class D amplifiers

The present disclosure relates to Class D amplifier circuitry comprising: an input for receiving an input signal; first and second output nodes for driving a load connected between the first and second output nodes. A first driver stage is provided for switching the first node between a first supply rail and a second supply rail, and a second driver stage is provided for switching the second node between the first supply rail and the second supply rail. The Class D amplifier circuitry also includes first driver control circuitry configured to receive a first carrier wave and control the switching of the first driver stage based in part on the first carrier wave; second driver control circuitry configured to receive a second carrier wave and control the switching of the second driver stage based in part on the second carrier wave; and a carrier wave generator configured to provide the first carrier wave and the second carrier wave. A phase shift between the first carrier wave and the second ...

Water-soluble metal working oil agent

A water-soluble metal working oil agent which can be prevented from being scattered in the form of mists for a long period when used for the cutting processing, grinding processing and the like of metallic materials is provided. A method for producing the water-soluble metal working oil agent is described. The water-soluble metal working oil agent includes a polyalkylene oxide having a weight average molecular weight of 100,000 to 1,000,000 and water.

Polyalkylene oxide particles and production method for the same

The present invention relates to a production method of polyalkylene oxide particles including a step of forming the polyalkylene oxide particles by polymerization of an alkylene oxide in a polymerization solution containing a polymerization solvent and a catalyst dispersed in the polymerization solvent. The average particle diameter of the catalyst is 25 μm or less.

Water-soluble metal working oil agent

To provide: a water-soluble metal working oil agent which can be prevented from being scattered in the form of mists for a long period when used for the cutting processing, grinding processing and the like of metallic materials; and a method for producing the water-soluble metal working oil agent. The water-soluble metal working oil agent according to the present invention comprises a polyalkylene oxide having a weight average molecular weight of 100,000 to 1,000,000 and water.

POLYALKYLENE OXIDE PARTICLES AND PRODUCTION METHOD FOR THE SAME

The present invention relates to a production method of polyalkylene oxide particles including a step of forming the polyalkylene oxide particles by polymerization of an alkylene oxide in a polymerization solution containing a polymerization solvent and a catalyst dispersed in the polymerization solvent. The average particle diameter of the catalyst is more than 25 μm. 1. A production method of polyalkylene oxide particles , comprising:forming polyalkylene oxide particles by polymerization of an alkylene oxide in a polymerization solution containing a polymerization solvent and a catalyst dispersed in the polymerization solvent,wherein the average particle diameter of the catalyst is more than 25 μm.2. The production method according to claim 1 ,wherein the catalyst is an organozinc catalyst.3. The production method according to claim 2 ,wherein the organozinc catalyst is a particulate reaction product obtainable by a method including: reacting an organozinc compound with an aliphatic polyhydric alcohol and a monohydric alcohol, thereby forming a particulate reaction product.4. The production method according to claim 1 ,wherein the polymerization solution contains 0.00005 mol or more of the catalyst with respect to 1 mol of the alkylene oxide.5. Polyalkylene oxide particles obtainable by the production method according to claim 1 ,wherein the proportion of particles having a particle diameter less than 150 μm is less than 40% by mass. The present invention relates to polyalkylene oxide particles and a production method for the same.A polyalkylene oxide is water-soluble and thermoplastic, therefore, the polyalkylene oxide is used for uses such as a viscous agent for papermaking, a ceramic binder, a polymerization stability assistant and a material for a pharmaceutical preparation. When the polyalkylene oxide is used as a thickener such as a viscous agent for papermaking and the like, generally, the polyalkylene oxide having a high molecular weight is preferable from ...

Audio amplifiers

This application relates to methods and apparatus for amplification of audio signals with improved audio performance. An audio driving circuit has an amplifier module in a forward signal path between an input for receiving an input audio signal (SIN) and an output for outputting an audio driving signal (VOUT). A pre-distortion module is operable to apply a first transfer function to the signal in the forward signal path upstream of the amplifier module, wherein the first transfer function comprises a non-linear distortion function based on at least one distortion setting. An error block is arranged to receive a first signal (SFF) derived from the input signal and a second signal (SFB) indicative of the voltage of the audio driving signal and determine a first error signal (ε1) indicative of a difference between the first and second signals. The pre-distortion module is operable to control the distortion setting(s) based on the first error signal.

SIGNAL PROCESSING FOR MEMS CAPACITIVE TRANSDUCERS

This application relates to circuitry for processing sense signals generated by MEMS capacitive transducers for compensating for distortion in such sense signals. The circuitry has a signal path between an input () for receiving the sense signal and an output () for outputting an output signal based on said sense signal. Compensation circuitry () is configured to monitor the signal at a first point along the signal path and generate a correction signal (S); and modify the signal at at least a second point along said signal path based on said correction signal. The correction signal is generated as a function of the value of the signal at the first point along the signal path so as to introduce compensation components into the output signal that compensate for distortion components in the sense signal. The first point in the signal path may be before or after the second point in the signal path. The monitoring may be performed in an analogue or a digital part of the signal path and in either case the modification may be applied in an analogue or a digital part of the signal path. 1. A signal processing circuit for a MEMS capacitive transducer , the transducer producing , in use , a sense signal in response to an input stimulus , the signal processing circuit comprising:a signal path between an input for receiving said sense signal and an output for outputting an output signal based on said sense signal; and monitor the signal at a first point along the signal path and generate a correction signal; and', 'modify the signal at at least a second point along said signal path based on said correction signal;', 'wherein said correction signal is generated as a function of the value of the signal at the first point along the signal path so as to introduce compensation components into the output signal that compensate for distortion components in the sense signal., 'compensation circuitry configured to2. A signal processing circuit as claimed in wherein the first point in ...

Polyalkylene oxide particles and production method for same

The present invention pertains to a production method for polyalkylene oxide particles, comprising a step in which alkylene oxide is polymerized in a polymerization solution including a polymerization solvent and a catalyst dispersed in said polymerization solvent, and polyalkylene oxide particles are generated. The average particle diameter of the catalyst is no more than 25 [mu]m.

Drag reducer and fire-extinguishing agent

The invention provides a drag reducer having an excellent frictional drag-reducing effect on an aqueous medium and the like and also provides a fire-extinguishing agent including this drag reducer. The drag reducer according to the present invention includes a polyalkylene oxide aqueous dispersion that includes a polyalkylene oxide, aluminum oxide, an electrolyte, and water, and that has the polyalkylene oxide dispersed therein. The drag reducer has an excellent frictional drag-reducing effect on an aqueous medium and the like.

Papermaking method and papermaking machine

A papermaking method conducted using a papermaking machine which includes a pump (1), a screen (2) located downstream from the pump (1), and a head box (3) disposed downstream from the screen (2). Downstream from the pump (1), an aqueous papermaking thickener solution having a concentration of 0.1-3.0 wt.% is added to a feed pulp slurry from which impurities are to be removed with the screen (2).

Polyalkylene oxide particles and production method for same

The present invention pertains to a production method for polyalkylene oxide particles, comprising a step in which alkylene oxide is polymerized in a polymerization solution including a polymerization solvent and a catalyst dispersed in said polymerization solvent, and polyalkylene oxide particles are generated. The average particle diameter of the catalyst is greater than 25 micrometer.

DYNAMIC ELEMENT MATCHING METHOD AND DEVICE

PROBLEM TO BE SOLVED: To reduce a switching quantity of an analog segment functioning as a weight generator, to reduce distortion, and to improve distortion performance by allowing the processing speed of DEM (dynamic element matching) to be a speed lower than input of a DEM processing application target. SOLUTION: The DEM device executes dynamic matching processing for digital input at a second time rate different from a first time rate of the digital input. In one embodiment, the DEM device consists of an encoder 10 and a feedback circuit 12. The encoder 10 is provided with two inputs and one output. In the encoder 10, the digital input as a target of the DEM processing is received in one of the two inputs, the output of the feedback circuit 12 is received to the other input, and digital output of a result of encoding is generated on the output. The feedback circuit 12 is provided with a sampling rate converter 120, and a loop filter 122 in order to execute the DEM processing at a time ...

Pop noise suppression technique

A voltage supply circuit and a circuit device can reduce the noise in the output of the circuit when the power to the circuit is turned on and off and can shorten the time required to start or stop the operation of the circuit. When the supply of power to signal processing part 10 is started or stopped, reference voltage Vref supplied to signal processing part 10 is varied continuously to reduce the high-frequency noise in the output of signal processing part 10. Also, when the setpoint value of the waveform of reference voltage Vref is generated by digital signal processing in voltage setting part 30, the desired waveform can be generated without being limited by the values of the circuit elements or the circuit configuration. The output noise of signal processing part 10 can be reduced, and the time that reference time Vref varies can be shortened.

COMPUTING CIRCUITRY

This application relates to methods and apparatus for computing, especially to circuitry for performing computing, at least partly, in the analogue domain. The circuitry (200) comprises a plurality of memory cells (201), each memory cell having first and second paths between an electrode (202) for receiving an input current and respective positive and negative electrodes (203) for outputting a differential-current output. Memristors (101) are located in the first and second paths. The memory cells are configured into sets (205) of memory cells, the memory cells of each said set being connected so as to provide a differential current set output that corresponds to a combination of the cell outputs of all of the memory cells of that set. For each set, at least some of the memory cells of that set are configured to receive a different input current to other memory cells of that set.

NEW THIOPHENE CARBOXAMIDE DERIVATIVE AND MEDICAL USE THEREOF

PROBLEM TO BE SOLVED: To provide a compound having glucokinase activating action. SOLUTION: A medical composition containing a compound expressed by general formula (I) (wherein X denotes a nitrogen atom or CR6, R6 denotes a hydrogen atom; R1 denotes a hydrogen atom, a 1-6C alkyl group, a 1-6C alkoxy group or a 1-6C alkylthio group, R2 denotes a hydrogen atom or a fluorine atom; R3 denotes a hydrogen atom or a 1-6C alkyl group; and one of R4 and R5 denotes a hydrogen atom or a 1-6C alkyl group, and another thereof denotes a 1-6C alkylene carboxylic acid, a 1-6C alkylsulfonyl group, 1-6C alkylcarbonyl group or CONH2), a prodrug or a pharmacologically permitted salt as an active ingredient is provided. COPYRIGHT: (C)2011,JPO&INPIT ...

Method and apparatus for forming transient response characteristics

Transient response generating circuit A has a first circuit 3 that generates transient response OUT 1 in a first polarity direction, a second circuit 4 that generates transient response OUT 2 in a second polarity direction opposite to the first polarity, and a transient response synthesizing circuit 6 that combines the transient response OUT 1 in the first polarity direction and the transient response OUT 2 in the second polarity direction to generate composite transient response OUTC.

CLASS D AMPLIFIER CIRCUIT

PROBLEM TO BE SOLVED: To provide a class D amplifier circuit capable of suppressing noise that occurs when a class D amplification operation starts and ends. SOLUTION: A signal to be supplied to a load as a differential signal of output signals Pout1 and Pout2 is prevented from changing rapidly by gradually changing the pulse width and pulse interval of the output signals Pout1 and Pout2 and a reduction in noise can be achieved when a class D amplification operation starts and ends. Namely, the pulse width of the output signals Pout1 and Pout2 are made constant and the pulse interval is gradually changed to thereby be able to suppress a change in a relatively high frequency component that corresponds to a pulse signal component. The pulse interval of the output signals Pout1 and Pout2 are made constant and the pulse width is gradually changed, thereby suppressing a change in a relatively low frequency component that corresponds to the average value of the pulse signals. COPYRIGHT: (C)2009 ...

VOLTAGE SUPPLY CIRCUIT AND CIRCUIT DEVICE

A voltage supply circuit and a circuit device can reduce the noise in the output of the circuit when the power to the circuit is turned on and off and can shorten the time required to start or stop the operation of the circuit. When the supply of power to signal processing part 10 is started or stopped, reference voltage Vref supplied to signal processing part 10 is varied continuously to reduce the high-frequency noise in the output of signal processing part 10 . Also, when the setpoint value of the waveform of reference voltage Vref is generated by digital signal processing in voltage setting part 30 , the desired waveform can be generated without being limited by the values of the circuit elements or the circuit configuration. The output noise of signal processing part 10 can be reduced, and the time that reference time Vref varies can be shortened.

Class-D amplifier circuits

Methods and apparatus for Class-D amplifier circuits with improved power efficiency. The circuit has an output stage with at least first and second switches and a modulator that receives an input signal to be amplified, S IN , and a first clock signal f SW . The modulator controls the duty cycles of the first and second switches, within a switching cycle based on the input signal, wherein the switching cycle has a switching frequency based on the first clock signal. A frequency controller controls the frequency of the first clock signal in response to an indication of the amplitude of the input signal so as to provide a first switching frequency at a first input signal amplitude and a second, lower, switching frequency at a second, lower, input signal amplitude. A lower switching frequency can be tolerated at low signal amplitudes and varying the switching frequency in this way thus maintains stability while reducing switching power losses.

Method for producing medium-molecular-weight polyalkyleneoxide

A method for producing a medium-molecular weight polyalkylene oxide having a viscosity-average molecular weight of from 100,000 to 2,500,000, including heat-treating a polyalkylene oxide having a viscosity-average molecular weight of 3,000,000 or more at a temperature of from 30° to 70° C. in an aliphatic hydrocarbon solvent having a dissolved oxygen concentration of 0.5 mg/L or more, in the presence of a radical initiator in an amount of from 0.001 to 1 part by mass, based on 100 parts by mass of the polyalkylene oxide, and thereafter adding an antioxidant to a mixture in an amount of from 0.001 to 5 parts by mass, based on 100 parts by mass of the polyalkylene oxide to remove the solvent. According to the method of the present invention, a medium-molecular weight polyalkylene oxide having a viscosity-average molecular weight of from 100,000 to 2,500,000 which has excellent storage stability can be industrially obtained without subjecting to a gamma-ray irradiation treatment.

ALKYLENE OXIDE POLYMER PRODUCTION METHOD

Provided is an alkylene oxide polymer production method, whereby it becomes possible to produce an alkylene oxide polymer having a high polymerization degree on an industrial scale and with high reproducibility. An alkylene oxide polymer production method comprising carrying out a polymerization reaction of an alkylene oxide in an inert hydrocarbon solvent in the presence of a zinc catalyst to produce an alkylene oxide polymer, wherein the zinc catalyst is produced by reacting an organozinc compound with a monohydric alcohol in an amount of 12-fold equivalent or less relative to the amount of the organozinc compound and an aliphatic polyhydric alcohol in an amount of 0.2- to 1.1-fold equivalent relative to the amount of the organozinc compound, and the polymerization reaction is carried out under such a condition that the amount of the monohydric alcohol in the polymerization reaction system becomes 0.01-fold equivalent or less relative to the amount of the organozinc compound.

PWM driver and class D amplifier using same

The objective of the invention is to provide a class D amplifier that can reduce aliasing noise. The class D amplifier has D/A converter 10 that operates at the first sampling frequency, and PWM driver 3 that receives the output from D/A converter 10. Said PWM driver 3 operates at the second sampling frequency synchronized to the first sampling frequency. The second sampling frequency can be correlated to the delta wave frequency of the PWM driver. Also, synchronization of said first sampling frequency and said second sampling frequency can be carried out with one of said frequencies being an integer multiple of the other.

Driver circuit for capacitive transducer

The present disclosure relates to a circuit for driving a capacitive transducer based on an input signal. The circuit includes: a primary driver circuit configured to receive the input signal and output a primary drive signal to the capacitive transducer based on the input signal; and a secondary driver circuit configured to receive an error signal indicative of an error between the input signal and the primary drive signal and to output a secondary drive signal to the capacitive transducer based on the error signal, wherein both the primary driver circuit and the secondary driver circuit include a switching converter circuit.

NEW THIOPHENECARBOXAMIDE DERIVATIVE AND MEDICINAL USE THEREOF

PROBLEM TO BE SOLVED: To provide a compound having glucokinase activation action. SOLUTION: The compound is represented by general formula (I) [wherein X is a nitrogen atom or CR6; R6 is a hydrogen atom or halogen atom; R1 is a hydrogen atom, 1C-6C alkyl, 1C-6C alkoxy or 1C-6C alkylthio; R2 is a hydrogen atom or fluorine atom; R3 is a hydrogen atom or 1C-6C alkyl; one of R4 and R5 is a hydrogen atom or 1C-6C alkyl and the other is a 1C-6C alkylenecarboxylic acid, 1C-6C alkylsulfonyl, 1C-6C alkylcarbonyl or CONH2]. COPYRIGHT: (C)2012,JPO&INPIT ...

VOLTAGE SUPPLY CIRCUIT AND CIRCUIT DEVICE

PROBLEM TO BE SOLVED: To provide a voltage supply circuit and a circuit device for reducing a time required for starting and finishing the operation of a circuit while reducing noise generated in the output of the circuit when the power source of the circuit is turned on or off. SOLUTION: When starting or stopping power supply to a signal processing part 10, a reference voltage Vref to be supplied to the signal processing part 10 is continuously changed, and a high-frequency noise to be generated in the output of the signal processing part 10 is reduced. Also, the set value of the waveform of the reference voltage Vref is generated by digital signal processing in a voltage setting part 30 to generate desired waveform without restriction on the value of the circuit element or circuit configurations, thereby reducing the changing time of the reference voltage Vref while reducing the output noise of the signal processing part 10. COPYRIGHT: (C)2009,JPO&INPIT ...

DIGITAL ENCODER, DYNAMIC ELEMENT MATCHING METHOD, DIGITAL/ANALOG CONVERTER, AND ANALOG/DIGITAL CONVERTER

PROBLEM TO BE SOLVED: To provide a digital encoder which enhances equalization in use frequency among a plurality of dynamic element matching circuits disposed in one stage. SOLUTION: The digital encoder (DEM circuit) 12 has a plurality of DEM circuits 12a and 12b disposed like a multi-stage tree and outputs a digital signal to each digital/analog conversion element 13a of a digital/analog conversion circuit 13. A master DEM circuit 12a divides an input value which a digital signal inputted to the circuit itself has, by the number of slave DEM circuits 12b and determines a slave DEM circuit 12b for use for expressing a remainder of the division. When the remainder is 0, the master DEM circuit 12a reduces a use priority of a slave DEM circuit 12b having the highest use priority and raises a use priority of a slave DEM circuit 12b having the lowest use priority. COPYRIGHT: (C)2010,JPO&INPIT ...

VOLTAGE SUPPLY CIRCUIT AND CIRCUIT DEVICE

PROBLEM TO BE SOLVED: To provide a voltage supply circuit and a circuit device capable of shortening a period of time required for the start and end of the operation of a circuit while reducing noise caused in the output of the circuit in the case of turning on or off the power source of the circuit. SOLUTION: In the case of starting or stopping power supply to a signal processing part 10, a reference voltage Vref to be supplied to the signal processing part 10 is continuously changed, and a noise with a high frequency to be generated in the output of the signal processing part 10 is reduced. Also, the set value of the waveform of the reference voltage Vref is generated by digital signal processing in a voltage setting part 30 so that it is possible to generate desired waveform without receiving the constraint of the value of the circuit element or circuit configurations. Therefore, it is possible to shorten the changing time of the reference voltage Vref while reducing the output noise ...

Driver circuitry for piezoelectric transducers

The present disclosure relates to circuitry for driving a piezoelectric transducer based on an input signal. The circuitry comprises: primary driver circuitry configured to receive the input signal and to output a primary driving signal to the piezoelectric transducer based on the input signal; and secondary driver circuitry configured to receive an error signal indicative of an error between the input signal and the primary driving signal and to output a secondary driving signal to the piezoelectric transducer based on the error signal, wherein the primary driver circuitry and the secondary driver circuitry both comprise switching converter circuitry.

CLASS D AMPLIFIER CIRCUIT

This application relates to Class D amplifier circuits (). A modulator () controls a Class D output stage () based on a modulator input signal (Dm) to generate an output signal (Vout) which is representative of an input signal (Din). An error block (), which may comprise an ADC (), generates an error signal (ε) from the output signal and the input signal. In various embodiments the extent to which the error signal (ε) contributes to the modulator input signal (Dm) is variable based on an indication of the amplitude of the input signal (Din). The error signal may be received at a first input () of a signal selector block (). The input signal may be received at a second input () of the signal selector block (). The signal selector block may be operable in first and second modes of operation, wherein in the first mode the modulator input signal is based at least in part on the error signal; and in the second mode the modulator input signal is based on the digital input signal and is independent of the error signal. The error signal can be used to reduce distortion at high signal levels but is not used at low signal levels and so the noise floor at low signal levels does not depend on the component of the error block (). 1. A Class D amplifier circuit for receiving a digital input signal and outputting an analog output signal comprising:a class-D output stage;a digital modulator for generating at least one control signal for controlling said class-D output stage based on a modulator input signal;an error block for generating an error signal based on said output signal and said digital input signal; in the first mode the modulator input signal is based at least in part on the error signal; and', 'in the second mode the modulator input signal is based on the digital input signal and is independent of the error signal; and, 'said signal selector block is operable in a first mode and a second mode of operation, wherein, 'a signal selector block configured to receive the ...

COUGH DETECTION

A method of cough detection in a headset, the method comprising: receiving a first signal from an external transducer of the headset; receiving a second signal from an in-ear transducer of the headset; and detecting a cough of a user of the headset based on the first and second signals. 121.-. (canceled)22. An apparatus for cough detection , comprising:a first input for receiving a first signal from an first transducer of a personal audio device;a second input for receiving a second signal from an second transducer of the personal audio device; andone or more processors configured to:detect a cough of a user of the personal audio device based on the first and second signals.23. The apparatus of claim 22 , wherein the first transducer is an external transducer and the second transducer is an in-ear transducer.24. The apparatus of claim 22 , wherein detecting the cough comprises:detecting a cough event in the first signal;detecting a cough event in the second signal.25. The apparatus of claim 23 , wherein detecting the cough comprises:determining a correlation between the cough event in the first audio signal and a cough event in the second signal.26. The apparatus of claim 22 , wherein detecting the cough comprises:determining a first energy in a first frequency band of the first signal;determining a second energy in a second frequency band of the first signal; anddetermining an third energy in a third frequency band of the second signal, wherein the first frequency band has a higher centre frequency than the second frequency band and the third frequency band.27. The apparatus of claim 25 , wherein:determining the first energy comprises high pass filtering the first signal;determining the second energy comprises low pass filtering the first signal; anddetermining the third energy comprises low pass filtering the second signal.28. The apparatus of claim 27 , further comprising:determining a change of orientation of the personal audio device; anddetecting the cough ...

WATER-SOLUBLE METAL WORKING OIL AGENT

A water-soluble metal working oil agent which can be prevented from being scattered in the form of mists for a long period when used for the cutting processing, grinding processing and the like of metallic materials is provided. A method for producing the water-soluble metal working oil agent is described. The water-soluble metal working oil agent includes a polyalkylene oxide having a weight average molecular weight of 100,000 to 1,000,000 and water. 1. A water-soluble metal working oil comprising a polyalkylene oxide having a weight average molecular weight of 100 ,000 to 1 ,000 ,000 , a base oil and water.2. The water-soluble metal working oil according to claim 1 , wherein the carbon number of a monomer unit that forms the polyalkylene oxide is 2 to 4.3. The water-soluble metal working oil according to claim 1 , wherein the polyalkylene oxide comprises at least one monomer unit selected from the group consisting of an ethylene oxide unit claim 1 , a propylene oxide unit and a butylene oxide unit.4. The water-soluble metal working oil according to claim 1 , wherein the polyalkylene oxide is at least one selected from the group consisting of a polyethylene oxide claim 1 , a polypropylene oxide claim 1 , a polybutylene oxide claim 1 , an ethylene oxide-propylene oxide copolymer claim 1 , an ethylene oxide-butylene oxide copolymer and a propylene oxide-butylene oxide copolymer.5. The water-soluble metal working oil according to claim 1 , wherein the content of the polyalkylene oxide is 0.1 to 5% by mass.6. The water-soluble metal working oil according to claim 1 , wherein the viscosity is 5 to 10 claim 1 ,000 mPa·s.7. The water-soluble metal working oil according to claim 1 , wherein the water-soluble metal working oil is used for cutting processing or grinding processing of a metallic material.8. A method for producing the water-soluble metal working oil according to claim 1 , the method comprising the mixing a polyalkylene oxide with water claim 1 , wherein the ...

Driver circuitry

The present disclosure relates to circuitry for driving a load. The circuitry comprises driver circuitry configured to generate a drive signal, based on an input signal to the driver circuitry, for driving the load, and commutator circuitry for coupling the driver circuitry to the load. The commutator circuitry is configured to alternate between commutation states in response to a level of the drive signal meeting a drive signal threshold or in response to a level of the input signal meeting a first input signal threshold. The circuitry is configured to apply an offset to the input signal when the input signal is below a second input signal threshold so as to increase a minimum level of the drive signal above the drive signal threshold or to increase a minimum level of the input signal above the first input signal threshold.

FRACTURING FLUID VISCOSITY-CONTROLLING AGENT TO BE USED IN HYDRAULIC FRACTURING

A fracturing fluid viscosity-controlling agent is described. The fracturing fluid viscosity-controlling agent is capable of maintaining the high viscosity of the fracturing fluid during fracture formation in hydraulic fracturing and of reducing the viscosity during recovery of the fracturing fluid. A fracturing fluid which includes the viscosity-controlling agent is provided as well as a crude oil or natural gas drilling method using the fracturing fluid with the viscosity-controlling agent. This viscosity-controlling agent contains polyalkylene oxide and a viscosity-reducing agent and is in the form of a tablet. 1. A viscosity controlling agent for controlling a change in viscosity of a fracturing fluid to be used in hydraulic fracturing ,wherein the viscosity controlling agent comprises a polyalkylene oxide and a viscosity reducing agent and being in the form of a tablet.2. The viscosity controlling agent according to claim 1 , wherein the ratio of the polyalkylene oxide in the viscosity controlling agent is 30 to 99.99% by mass.3. The viscosity controlling agent according to claim 1 , wherein the mass of the tablet is 0.2 g or more.4. The viscosity controlling agent according to claim 1 , wherein the polyalkylene oxide has a viscosity of 20 to 1 claim 1 ,500 mPa·s in the form of a 0.5 mass % aqueous solution at 25° C. claim 1 , or a viscosity of 50 to 80 claim 1 ,000 mPa·s in the form of a 5 mass % aqueous solution at 25° C.5. The viscosity controlling agent according to claim 1 , wherein the viscosity reducing agent is at least one selected from the group consisting of a radical generator claim 1 , an acid and an enzyme.6. The viscosity controlling agent according to claim 1 , wherein the carbon number of a monomer unit that forms the polyalkylene oxide is 2 to 4.7. The viscosity controlling agent according to claim 1 , wherein the polyalkylene oxide contains at least one monomer unit selected from the group consisting of an ethylene oxide unit claim 1 , a ...

DRIVER CIRCUITRY

The present disclosure relates to circuitry for driving a piezoelectric transducer. The circuitry comprises amplifier circuitry configured to receive a drive signal and to output an output signal, based on the drive signal, to the piezoelectric transducer, a variable capacitor configured to be coupled in series with the piezoelectric transducer, and control circuitry. The control circuitry is configured to control a capacitance of the variable capacitor to compensate for hysteresis in the piezoelectric transducer and to control a gain of the amplifier circuitry to compensate for signal attenuation caused by the variable capacitor. 1. Circuitry for driving a piezoelectric transducer , the circuitry comprising:amplifier circuitry configured to receive a drive signal and to output an output signal, based on the drive signal, to the piezoelectric transducer;a variable capacitor configured to be coupled in series with the piezoelectric transducer; andcontrol circuitry, wherein the control circuitry is configured to control a capacitance of the variable capacitor to compensate for hysteresis in the piezoelectric transducer and to control a gain of the amplifier circuitry to compensate for signal attenuation caused by the variable capacitor.2. Circuitry according to claim 1 , wherein the control circuitry is configured to control the gain of the amplifier circuitry and the capacitance of the variable capacitor based at least in part on a parameter of the drive signal received by the amplifier circuitry.3. Circuitry according to claim 2 , wherein the parameter comprises one or more of:a volume of an audio signal represented by the drive signal;an envelope of the drive signal; andan instantaneous value of the drive signal.4. Circuitry according to wherein the control circuitry is configured to monitor a signal at a node coupled to the piezoelectric transducer and to control the gain of the amplifier circuitry and the capacitance of the variable capacitor based at least in ...

METHOD FOR PRODUCING MEDIUM-MOLECULAR-WEIGHT POLYALKYLENEOXIDE

A method for producing a medium-molecular weight polyalkylene oxide having a viscosity-average molecular weight of from 100,000 to 2,500,000, including heat-treating a polyalkylene oxide having a viscosity-average molecular weight of 3,000,000 or more at a temperature of from 30° to 70° C. in an aliphatic hydrocarbon solvent having a dissolved oxygen concentration of 0.5 mg/L or more, in the presence of a radical initiator in an amount of from 0.001 to 1 part by mass, based on 100 parts by mass of the polyalkylene oxide, and thereafter adding an antioxidant to a mixture in an amount of from 0.001 to 5 parts by mass, based on 100 parts by mass of the polyalkylene oxide to remove the solvent. According to the method of the present invention, a medium-molecular weight polyalkylene oxide having a viscosity-average molecular weight of from 100,000 to 2,500,000 which has excellent storage stability can be industrially obtained without subjecting to a gamma-ray irradiation treatment. 1. A method for producing a medium-molecular weight polyalkylene oxide , the method comprisingheat-treating a polyalkylene oxide having a viscosity-average molecular weight of 3,000,000 or more at a temperature of from 30° to 70° C. in an aliphatic hydrocarbon solvent comprising dissolved oxygen at a concentration of 0.5 mg/L or more, in the presence of a radical initiator in an amount of from 0.001 to 1 part by mass, based on 100 parts by mass of the polyalkylene oxide, andthereafter adding an antioxidant in an amount of from 0.001 to 5 parts by mass, based on 100 parts by mass of the polyalkylene oxide to remove the solvent, thereby obtaining the medium-molecular weight polyalkylene oxide, which has a viscosity-average molecular weight of from 100,000 to 2,500,000.2. The method according to claim 1 , wherein the radical initiator is a radical initiator whose 10-hour half-life temperature is 70° C. or lower.3. The method according to claim 1 , wherein the antioxidant is at least one selected ...

Class d amplifier circuit

This application relates to Class D amplifier circuits ( 200 ). A modulator ( 201 ) controls a Class D output stage ( 202 ) based on a modulator input signal (Dm) to generate an output signal (Vout) which is representative of an input signal (Din). An error block ( 205 ), which may comprise an ADC ( 207 ), generates an error signal (ϵ) from the output signal and the input signal. In various embodiments the extent to which the error signal (ϵ) contributes to the modulator input signal (Dm) is variable based on an indication of the amplitude of the input signal (Din). The error signal may be received at a first input ( 204 ) of a signal selector block ( 203 ). The input signal may be received at a second input ( 206 ) of the signal selector block ( 203 ). The signal selector block may be operable in first and second modes of operation, wherein in the first mode the modulator input signal is based at least in part on the error signal; and in the second mode the modulator input signal is based on the digital input signal and is independent of the error signal. The error signal can be used to reduce distortion at high signal levels but is not used at low signal levels and so the noise floor at low signal levels does not depend on the component of the error block ( 205 ).

CLASS D AMPLIFIERS

The present disclosure relates to Class D amplifier circuitry comprising a mode controller configured to dynamically adjust an operational switching mode of the Class D amplifier over a range between a Class AD mode and a Class BD mode. 1. A Class D amplifier comprising a controller configured to dynamically adjust an operational switching mode of the Class D amplifier over a range between a Class AD mode and a Class BD mode.2. A Class D amplifier according to claim 1 , wherein the controller is configured to dynamically adjust the operational switching mode in dependence on an indication of a characteristic claim 1 , parameter or feature of an input signal to be amplified.3. A Class D amplifier according to claim 2 , wherein the indication of a characteristic claim 2 , parameter or feature comprises an indication of a level or an envelope of the input signal.4. A Class D amplifier according to claim 1 , wherein the range between the Class AD mode and the Class BD mode has a first end point at which the operational switching mode is 100% Class AD and a second end point at which the operational switching mode is 100% Class BD.5. A Class D amplifier according to claim 1 , wherein the range between the class AD mode and the Class BD mode has a first point at which the operational switching mode is less than 100% class AD or a second end point at which the operational switching mode is less than 100% class BD.6. A Class D amplifier according to claim 1 , wherein the controller is operative to adjust a relative phase between first and second carrier signals to adjust the operational switching mode.7. A Class D amplifier according to claim 6 , wherein the Class D amplifier further comprises carrier wave generator circuitry configured to provide the first and second carrier signals.8. A Class D amplifier according to claim 7 , wherein the carrier wave generator comprises:a source carrier wave input for receiving a source carrier wave;a first carrier wave output for ...

Drag reducer and fire-extinguishing agent

The invention provides a drag reducer having an excellent frictional drag-reducing effect on an aqueous medium and the like and also provides a fire-extinguishing agent including this drag reducer. The drag reducer according to the present invention includes a polyalkylene oxide aqueous dispersion that includes a polyalkylene oxide, aluminum oxide, an electrolyte, and water, and that has the polyalkylene oxide dispersed therein. The drag reducer has an excellent frictional drag-reducing effect on an aqueous medium and the like.

CLASS D AMPLIFIERS

The present disclosure relates to Class D amplifier circuitry comprising: an input for receiving an input signal; first and second output nodes for driving a load connected between the first and second output nodes. A first driver stage is provided for switching the first node between a first supply rail and a second supply rail, and a second driver stage is provided for switching the second node between the first supply rail and the second supply rail. The Class D amplifier circuitry also includes first driver control circuitry configured to receive a first carrier wave and control the switching of the first driver stage based in part on the first carrier wave; second driver control circuitry configured to receive a second carrier wave and control the switching of the second driver stage based in part on the second carrier wave; and a carrier wave generator configured to provide the first carrier wave and the second carrier wave. A phase shift between the first carrier wave and the second carrier wave is adjustable responsive to a mode control signal. 166.-. (canceled)67. Class D amplifier circuitry comprising:an input for receiving an input signal;first and second output nodes for driving a load connected between the first and second output nodes;a first driver stage for switching the first node between a first supply rail and a second supply rail;a second driver stage for switching the second node between the first supply rail and the second supply rail;first driver control circuitry configured to receive a first carrier wave and control the switching of the first driver stage based in part on the first carrier wave;second driver control circuitry configured to receive a second carrier wave and control the switching of the second driver stage based in part on the second carrier wave; anda carrier wave generator configured to provide the first carrier wave and the second carrier wave, wherein a phase shift between the first carrier wave and the second carrier wave ...

Fracturing fluid viscosity-controlling agent in tablet form and containing a polyalkylene oxide and a viscosity reducing agent

[Problem] To provide: a fracturing fluid viscosity-controlling agent, which is capable of maintaining the high viscosity of the fracturing fluid during fracture formation in hydraulic fracturing and of reducing the viscosity during recovery of the fracturing fluid; a fracturing fluid comprising said viscosity-controlling agent; and a crude oil or natural gas drilling method using said fracturing fluid. [Solution] This viscosity-controlling agent, which is used for controlling viscosity changes of a fracturing fluid used in hydraulic fracturing, comprises polyalkylene oxide and a viscosity-reducing agent and is a tablet.

Class-D Amplifier Circuits

Fracturing fluid viscosity-controlling agent to be used in hydraulic fracturing

Class-D Amplifier circuits

A class-D amplifier circuit includes an output stage 101 having at least first and second switches, a modulator 104 and a frequency controller 301. The modulator has a switching cycle frequency based on a received first clock signal FIN, and controls the duty cycles of the first and second switches within the switching cycle based on a received input signal, e.g. audio. In response to an indication of the amplitude of the input signal, which may be from the input signal SIN, volume control VOL, envelope value, or modulator output (Fig.16), the frequency controller controls the first clock signal to provide first and second switching frequencies fSW, where a lower switching frequency is provided at the second, lower, input signal amplitude. The controller implements the transition between switching frequencies over a period of time (Fig. 9a), applying a gradual rate of change of switching frequency at the beginning and end of a transition and an increased rate in the middle, e.g. sinusoidal (Fig. 9b). Switching losses in a class-D audio amplifier are reduced by reducing the switching frequency at low signal amplitudes, and output signal transients caused by a switching frequency transition are reduced using a gradual or smoothed rate of change.

Cell balancing

Cell balancing

Cough detection

A method of cough detection in a headset, the method comprising: receiving a first signal from an external transducer of the headset; receiving a second signal from an in-ear transducer of the headset; and detecting a cough of a user of the headset based on the first and second signals.

Cell balancing

Driver circuitry

The present disclosure relates to circuitry for driving a capacitive load. The circuitry comprises amplifier circuitry configured to receive a drive signal and to output an output signal, based on the drive signal, to the capacitive load, a variable capacitor configured to be coupled in series with the capacitive load, and control circuitry. The control circuitry is configured to control a capacitance of the variable capacitor to compensate for hysteresis in the capacitive load and to control a gain of the amplifier circuitry to compensate for signal attenuation caused by the variable capacitor.

Detection of live speech

A method of detecting live speech comprises: receiving a signal containing speech; obtaining a first component of the received signal in a first frequency band, wherein the first frequency band includes audio frequencies; and obtaining a second component of the received signal in a second frequency band higher than the first frequency band. Then, modulation of the first component of the received signal is detected; modulation of the second component of the received signal is detected; and the modulation of the first component of the received signal and the modulation of the second component of the received signal are compared. It may then be determined that the speech may not be live speech, if the modulation of the first component of the received signal differs from the modulation of the second component of the received signal.

Controlled drug release preparation composition and controlled drug release preparation

Provided is a controlled drug release preparation composition that can control the initial drug dissolution speed of a controlled drug release preparation by simple means, and the controlled drug release preparation.The osmotic pump controlled drug release preparation composition of the present invention comprises polyalkylene oxide particles D, and polyalkylene oxide particles D comprise 40 mass% or less of polyalkylene oxide particles having a particle size of 300 µm or more.

Driver circuitry

The present disclosure relates to circuitry for driving a load. The circuitry comprises driver circuitry configured to generate a drive signal, based on an input signal to the driver circuitry, for driving the load, and commutator circuitry for coupling the driver circuitry to the load. The commutator circuitry is configured to alternate between commutation states in response to a level of the drive signal meeting a drive signal threshold or in response to a level of the input signal meeting a first input signal threshold. The circuitry is configured to apply an offset to the input signal when the input signal is below a second input signal threshold so as to increase a minimum level of the drive signal above the drive signal threshold or to increase a minimum level of the input signal above the first input signal threshold.

Class D amplifiers

The invention relates to Class D amplifier circuitry 202 configured to adjust its operational switching mode between a Class AD mode and a Class BD mode in dependence on an indication of a characteristic, parameter or feature of an input signal to be amplified, e.g. on an input signal level or on a characteristic of the envelope. It is also disclosed that a mode controller 204 may dynamically adjust an operational switching mode of the Class D amplifier over a range between a Class AD mode and a Class BD mode (fig.1). The amplifier circuit may operate in multiple different modes ranging from 100% class AD to 100% class BD, e.g. in one or more intermediate ‘ADBD’ modes. The invention allows the most appropriate operating mode of a class D amplifier to be selected, thus enabling the benefits of each operating mode to be realised in a single amplifier.

Class d amplifiers

The present disclosure relates to Class D amplifier circuitry comprising: an input for receiving an input signal; first and second output nodes for driving a load connected between the first and second output nodes. A first driver stage is provided for switching the first node between a first supply rail and a second supply rail, and a second driver stage is provided for switching the second node between the first supply rail and the second supply rail. The Class D amplifier circuitry also includes first driver control circuitry configured to receive a first carrier wave and control the switching of the first driver stage based in part on the first carrier wave; second driver control circuitry configured to receive a second carrier wave and control the switching of the second driver stage based in part on the second carrier wave; and a carrier wave generator configured to provide the first carrier wave and the second carrier wave. A phase shift between the first carrier wave and the second carrier wave is adjustable responsive to a mode control signal.

Apparatus and methods for transferring charge

Apparatus for delivering power from a battery node of a battery to an output node, the output node coupled to an analyte monitoring device, the apparatus comprising: a slow charging path between the battery node and the output node; a fast charging path parallel to the slow charging path, the fast charging path switchably coupled between the battery node and the output node; and control circuitry configured to: selectively couple the fast charging path between the battery node and the output node to allow faster transfer of charge between the battery node and the output node than the slow charging path.

薬物放出制御製剤用組成物及び薬物放出制御製剤

【課題】簡便な手段によって薬物放出制御製剤の初期の薬物溶出速度を制御することができる薬物放出制御製剤用組成物及び薬物放出制御製剤を提供する。【解決手段】本発明の浸透圧ポンプ型の薬物放出制御剤用組成物は、ポリアルキレンオキシド粒子Ｄを含有し、ポリアルキレンオキシド粒子Ｄは、１８０μｍ以上の粒子径を有するポリアルキレンオキシド粒子を５０質量％以上含有する。本発明の薬物放出制御剤は、前記薬物放出制御製剤用組成物を含み、コア部と、該コア部を被覆する被覆層を備える浸透圧ポンプ型の構造を有し、前記コア部は、薬物を含む薬物層と、浸透圧誘起剤を含むポンプ層とを有し、前記被覆層は、少なくとも一部が半透膜であり、前記薬物を外部に放出するための開口部を被覆層に備え、前記薬物層は、前記薬物放出制御製剤用組成物を含有する。【選択図】なし

Driver circuitry for piezoelectric transducers

The present disclosure relates to circuitry for driving a piezoelectric transducer based on an input signal. The circuitry comprises: primary driver circuitry configured to receive the input signal and to output a primary driving signal to the piezoelectric transducer based on the input signal; and secondary driver circuitry configured to receive an error signal indicative of an error between the input signal and the primary driving signal and to output a secondary driving signal to the piezoelectric transducer based on the error signal, wherein the primary driver circuitry and the secondary driver circuitry both comprise switching converter circuitry.

Cell balancing

Balancing circuitry for balancing a set of N cells in a battery, the balancing circuitry comprising: a switch network configured to be coupled to the cells; and a set of capacitors coupled in parallel between the switch network and a common node, wherein the switch network is controllable such that: during a first phase of operation of the balancing circuitry the set of capacitors is coupled to a first subset comprising N−1 adjacent cells of the set of N cells; and during a second phase of operation the set of capacitors is coupled to a second subset comprising N−1 adjacent cells of the set of N cells, wherein the second subset is different from the first subset, and wherein, in use of the balancing circuitry, the common node is coupled intermittently, periodically or permanently to a reference voltage.

Cell balancing

Circuitry for balancing cells in a battery pack, the circuitry comprising: cell balancing circuitry configured to transfer energy between cells of the battery pack in synchronisation with a clock signal; and control circuitry configured to control a parameter of the clock signal based on a monitored parameter or information associated with the battery pack.

Circuitry for analyte measurement

Circuitry for measuring a characteristic of an electrochemical cell, the circuitry comprising: a comparator having a first comparator input, a second comparator input and a comparator output; a feedback path between the comparator output and the second comparator input configured to provide a feedback signal to the second comparator input; and a loop filter configured to apply filtering to the feedback path to generate the feedback signal, wherein the loop filter comprises the electrochemical cell.

Driver circuitry

The present disclosure relates to circuitry for driving a load. The circuitry comprises driver circuitry configured to generate a drive signal, based on an input signal to the driver circuitry, for driving the load, and commutator circuitry for coupling the driver circuitry to the load. The commutator circuitry is configured to alternate between commutation states in response to a level of the drive signal meeting a drive signal threshold or in response to a level of the input signal meeting a first input signal threshold. The circuitry is configured to apply an offset to the input signal when the input signal is below a second input signal threshold so as to increase a minimum level of the drive signal above the drive signal threshold or to increase a minimum level of the input signal above the first input signal threshold.

Computing circuitry

This application relates to computing circuitry ( 200, 500, 600 ) for analogue computing. A plurality of current generators ( 201 ) are each configured to generate a defined current (I D1 , I D2 , . . . I Dj ) based on a respective input data value (D 1 , D 2 , . . . D j ). A memory array ( 202 ), having at least one set ( 204 ) of programmable-resistance memory cells ( 203 ), is arranged to receive the defined currents from each of the current generators at a respective signal line ( 206 ). Each set ( 204 ) of programmable-resistance memory cells ( 203 ) includes a memory cell associated with each signal line that, in use, can be connected between the relevant signal line and a reference voltage so as to generate a voltage on the signal line. An adder module ( 207 ) is coupled to each of the signal lines to generate a voltage at an output node ( 210 ) based on the sum of the voltages on each of the signal lines.

Controlled drug release preparation composition and controlled drug release preparation

Class D amplifier circuit

This application relates to Class D amplifier circuits. A modulator controls a Class D output stage based on a modulator input signal (Dm) to generate an output signal (Vout) which is representative of an input signal (Din). An error block, which may comprise an ADC, generates an error signal (ε) from the output signal and the input signal. In various embodiments the extent to which the error signal (ε) contributes to the modulator input signal (Dm) is variable based on an indication of the amplitude of the input signal (Din). The error signal may be received at a first input of a signal selector block. The input signal may be received at a second input of the signal selector block. The signal selector block may be operable in first and second modes of operation, wherein in the first mode the modulator input signal is based at least in part on the error signal; and in the second mode the modulator input signal is based on the digital input signal and is independent of the error signal. The error signal can be used to reduce distortion at high signal levels but is not used at low signal levels and so the noise floor at low signal levels does not depend on the component of the error block.

Electrochemical cell characterisation

Circuitry 400 for determining an impedance of an electrochemical cell 402 comprising at least one first electrode and a second electrode, the circuitry comprising: drive circuitry configured to apply a stimulus V to the electrochemical cell; sense circuitry 404 configured to measure a response of the electrochemical cell to the stimulus; and processing circuitry 406 configured to: determine an estimated transfer function of the electrochemical cell based on the stimulus and the response; determine a score for the estimated transfer function; and adjust the stimulus or circuitry used to measure the response based on the score. The processing circuitry may be configured to determine the impedance of the electrochemical cell based on the estimated transfer function and the impedance of the cell may be determined based on the estimated transfer function if the score is above a first confidence threshold

Apparatus and method for discharging a battery with improved efficiency

Apparatus for delivering power from a battery node of a battery to an output node, the apparatus comprising: a slow charging path between the battery node and the output node; a fast charging path parallel to the slow charging path, the fast charging path switchably coupled between the battery node and the output node; and control circuitry configured to: selectively couple the fast charging path between the battery node and the output node to allow faster transfer of charge between the battery node and the output node than the slow charging path.

Driver circuitry for capacitive transducers

The present disclosure relates to driver circuitry (200) for driving a capacitive transducer (210), e.g., a piezoelectric transducer or an electrostatic transducer. The circuitry (200) comprises: a power supply (260); a reservoir capacitance (220); switch network circuitry (240); and control circuitry (270). The control circuitry (270) is configured to control operation of the switch network circuitry (240) so as to charge the reservoir capacitance (220) from the power supply (260) and to transfer charge between the reservoir capacitance (220) and the capacitive transducer (210).

Pulse-width modulation

This application relates to PWM modulation. A PWM modulator 400 comprises an input Sin for receiving an input signal; a clock input CLK1 for receiving a first clock signal; and a pulse generator for generating pulses in PWM cycle periods wherein the pulses and the PWM cycle periods are synchronised to the first clock signal and a duration of a pulse in a PWM cycle period is controlled based on the input signal. The pulse generator is operable to generate pulses that are not centred within a PWM cycle period and the position of a pulse in a PWM cycle period is controlled so as to compensate for non-centred pulses in one or more previous PWM cycle periods.

Class D amplifiers

The present disclosure relates to Class D amplifier circuitry comprising: an input for receiving an input signal; first and second output nodes for driving a load connected between the first and second output nodes. A first driver stage is provided for switching the first node between a first supply rail and a second supply rail, and a second driver stage is provided for switching the second node between the first supply rail and the second supply rail. The Class D amplifier circuitry also includes first driver control circuitry configured to receive a first carrier wave and control the switching of the first driver stage based in part on the first carrier wave; second driver control circuitry configured to receive a second carrier wave and control the switching of the second driver stage based in part on the second carrier wave; and a carrier wave generator configured to provide the first carrier wave and the second carrier wave. A phase shift between the first carrier wave and the second carrier wave is adjustable responsive to a mode control signal.

Computing circuitry for configuration and operation of cells and arrays comprising memristor elements

This application relates to methods and apparatus for computing, especially to circuitry for performing computing, at least partly, in the analogue domain. The circuitry ( 200 ) comprises a plurality of memory cells ( 201 ), each memory cell having first and second paths between an electrode ( 202 ) for receiving an input current and respective positive and negative electrodes ( 203 ) for outputting a differential-current output. Memristors ( 101 ) are located in the first and second paths. The memory cells are configured into sets ( 205 ) of memory cells, the memory cells of each said set being connected so as to provide a differential current set output that corresponds to a combination of the cell outputs of all of the memory cells of that set. For each set, at least some of the memory cells of that set are configured to receive a different input current to other memory cells of that set.

Amplifier and amplification method

An amplifier for a headphone is provided that can increase an upper limit on the amplitude of an audio signal generated between one common terminal and the output terminals of left and right channels, without raising the power supply voltage. The level at a common terminal C is changed corresponding to the average of the input audio signals (ViL, ViR) to increase the amplitudes of the output audio signals (VL, VR). In this way, the amplitudes of audio signals (VL, VR) supplied to the headphone can be increased compared with the case when the level at terminal C is kept constant. Also, the upper limit on the amplitudes of audio signals (VL, VR) can be increased without raising the power supply

Cell balancing

Balancing circuitry for balancing cells in first and second modules of a battery pack, wherein the first module comprises a first plurality of cells and the second module comprises a second plurality of cells, the balancing circuitry comprising: first cell balancing circuitry operative to balance the first plurality of cells of the first module; and second cell balancing circuitry operative to balance the second plurality of cells of the second module, wherein the second cell balancing circuitry is further operative to balance at least one cell of the first plurality of cells of the first module with at least one cell of the second plurality of cells of the second module.

Cell balancing

Balancing circuitry for balancing a set of N cells 812-816 in a battery 810, the balancing circuitry comprising: a switch network 842-852 configured to be coupled to the cells; and a set of capacitors 822-826 coupled in parallel between the switch network and a common node 828, wherein the switch network is controllable such that: during a first phase of operation of the balancing circuitry the set of capacitors is coupled to a first subset comprising N-1 adjacent cells of the set of N cells; and during a second phase of operation the set of capacitors is coupled to a second subset comprising N-1 adjacent cells of the set of N cells, wherein the second subset is different from the first subset, and wherein, in use of the balancing circuitry, the common node is coupled intermittently, periodically or permanently to a reference voltage.

Pulse-width modulation

Electrochemical cell characterisation

Circuitry for determining an impedance of an electrochemical cell comprising at least one first electrode and a second electrode, the circuitry comprising: drive circuitry configured to apply a stimulus to the electrochemical cell; sense circuitry configured to measure a response of the electrochemical cell to the stimulus; and processing circuitry configured to: determine an estimated transfer function of the electrochemical cell based on the stimulus and the response; determine a score for the estimated transfer function; and adjust the stimulus or circuitry used to measure the response based on the score.

Circuitry for measurement of electrochemical cells

Circuitry for characterising an electrochemical cell having a first electrode, a second electrode and a non-linear response characteristic, the circuitry comprising: difference circuitry configured to measure a potential difference across the electrochemical cell and output a difference voltage proportional to the measured potential difference; compensation circuitry configured to linearise the difference voltage and output a linearised difference signal; and a first analog-to-digital converter (ADC) configured to convert the linearised difference signal to a digital output.

Electrochemical cell characterisation

Circuitry for determining an impedance of an electrochemical cell comprising at least one first electrode and a second electrode, the circuitry comprising: drive circuitry configured to apply a stimulus to the electrochemical cell, the stimulus having a stimulation frequency and a stimulation amplitude; and measurement circuitry configured to: sample an output of the electrochemical cell at a sampling frequency to generate an output signal; determine an output amplitude of output signal at one or more alias frequencies, the one or more alias frequency based on the stimulation frequency and the sampling frequency; and determine the impedance of the cell at the stimulation frequency based on the output amplitude at the one or more alias frequencies and the stimulation amplitude; and control circuitry configured to: control the sampling frequency and the stimulation frequency such that a Nyquist rate of the sampling frequency is greater than stimulation frequency.

Cough detection

A method of cough detection in a headset, the method comprising: receiving a first signal from an external transducer of the headset; receiving a second signal from an in-ear transducer of the headset; and detecting a cough of a user of the headset based on the first and second signals.

Friction resistance reducing agent and fire-extinguishing agent

Cell balancing

Circuitry for balancing cells in a battery pack, the circuitry comprising: cell balancing circuitry configured to transfer energy between cells of the battery pack in synchronisation with a clock signal; and control circuitry configured to control a parameter of the clock signal based on a monitored parameter or information associated with the battery pack.

Driver circuitry

The present disclosure relates to circuitry for driving a capacitive load. The circuitry comprises amplifier circuitry configured to receive a drive signal and to output an output signal, based on the drive signal, to the capacitive load, a variable capacitor configured to be coupled in series with the capacitive load, and control circuitry. The control circuitry is configured to control a capacitance of the variable capacitor to compensate for hysteresis in the capacitive load and to control a gain of the amplifier circuitry to compensate for signal attenuation caused by the variable capacitor.

Circuitry for analyte measurement

Circuitry for and methods of analyte measurement Circuitry for measuring a characteristic of an electrochemical cell, the circuitry comprising: a hysteretic comparator having a first comparator input, a second comparator input and a comparator output; a feedback path between the comparator output and the second comparator input configured to provide a feedback signal to the second comparator input; and a loop filter configured to apply filtering to the feedback path to generate the feedback signal, wherein the loop filter comprises the electrochemical cell.

Circuitry for analyte measurement

Circuitry for and methods of analyte measurement Circuitry for measuring a characteristic of an electrochemical cell, the circuitry comprising: a hysteretic comparator having a first comparator input, a second comparator input and a comparator output; a feedback path between the comparator output and the second comparator input configured to provide a feedback signal to the second comparator input; and a loop filter configured to apply filtering to the feedback path to generate the feedback signal, wherein the loop filter comprises the electrochemical cell.

Pulse-width modulation

Driver circuitry for piezoelectric transducers

The present disclosure relates to driver circuitry for driving a piezoelectric transducer. The circuitry comprises: a power supply; a reservoir capacitance; switch network circuitry; and control circuitry. The control circuitry is configured to control operation of the switch network circuitry so as to charge the reservoir capacitance from the power supply and to transfer charge between the reservoir capacitance and the piezoelectric transducer.

Pulse-width modulation

Circuitry for Analyte Measurement

Circuitry for measuring a characteristic of an electrochemical cell, the circuitry comprising: a comparator having a first comparator input, a second comparator input and a comparator output; a feedback path between the comparator output and the second comparator input configured to provide a feedback signal to the second comparator input; and a loop filter configured to apply filtering to the feedback path to generate the feedback signal, wherein the loop filter comprises the electrochemical cell.

Pulse-width modulation

Pulse Width Modulation This application relates to digital PWM modulation. A PWM modulator (400, 1100) has a PWM generator (402) configured to receive pulse width data (P Width ) and to output a PWM signal (S PWM ) comprising a plurality of repeating PWM cycle periods, in which the duration of any pulse of the PWM signal in each PWM cycle period is based on the pulse width data. T he PWM generator is configured to synchronise the PWM cycle periods, and the start and end of any PWM pulse, to a received first clock signal. T he PWM generator is operable to generate pulses t hat have a positional error from a centred position within the PWM cycle period and a pulse position controller (403) is configured to control the position of a pulse in a PWM cycle period so as to at least partly compensate for the positional error of one or more preceding pulses.

Pulse-width modulation

This application relates to a PWM modulator 400 operable to generate a digital PWM signal wherein signal transitions in the PWM signal are synchronised to a first clock signal CLK 1. It is disclosed that the pulse generator may generate pulses that are not centred within a PWM cycle period. Therefore, the PWM modulator comprises a pulse position controller 403 configured to monitor any positional error arising from pulses that are not centred within the PWM cycle period and to control the position of a pulse in a subsequent PWM cycle period to compensate for this error.

Pulse-width modulation

Pulse Width Modulation This application relates to digital PWM modulation. A PWM modulator (400, 1100) has a PWM generator (402) configured to receive pulse width data (P Width ) and to output a PWM signal (S PWM ) comprising a plurality of repeating PWM cycle periods, in which the duration of any pulse of the PWM signal in each PWM cycle period is based on the pulse width data. T he PWM generator is configured to synchronise the PWM cycle periods, and the start and end of any PWM pulse, to a received first clock signal. T he PWM generator is operable to generate pulses t hat have a positional error from a centred position within the PWM cycle period and a pulse position controller (403) is configured to control the position of a pulse in a PWM cycle period so as to at least partly compensate for the positional error of one or more preceding pulses.

Electrochemical cell characterisation

Electrochemical cell 100, perhaps in a continuous glucose monitor, has first and second electrodes CE, WE. Drive circuitry applies stimulus VSTIM, with a stimulation frequency and amplitude, to the cell. A cell output is sampled at a sampling frequency, generating an output signal having an amplitude that is determined at one or more alias frequencies based on the stimulation frequency and sampling frequency. Cell impedance at the stimulation frequency is determined from the output amplitude at the alias frequencies and the stimulation amplitude. The stimulation and sampling frequencies are controlled so that the Nyquist rate of the sampling frequency is greater than the stimulation frequency. In an aspect, digital-to-analogue converter 306 converts digital input signal DSTIM into analogue VSTIM at a conversion frequency, and applies it to the second electrode. Analogue-to-digital converter 304 converts a first electrode signal into a digital output signal. The sampling frequency is controlled to be lower than the stimulation frequency.

Cough detection

A method of cough detection in a headset, the method comprising: receiving a first signal from an external transducer of the headset; receiving a second signal from an in-ear transducer of the headset; and detecting a cough of a user of the headset based on the first and second signals.

Driver circuitry for piezoelectric transducers

The present disclosure relates to driver circuitry for driving a piezoelectric transducer. The circuitry comprises: a power supply; a reservoir capacitance; switch network circuitry; and control circuitry. The control circuitry is configured to control operation of the switch network circuitry so as to charge the reservoir capacitance from the power supply and to transfer charge between the reservoir capacitance and the piezoelectric transducer.

Method for producing medium-molecular-weight polyalkyleneoxide