Receiver (reception module) for an optical communications path

A receiver 1, 23 for an optical communications path has an input amplifier (transimpedance amplifier 2, 5; high-impedance amplifier 17, 20) whose transmission function can be set along with internal transmission features by means of an assigned external matching resistor (negative feedback resistor 5; resistor 20 connected in parallel with the amplifier input 26). An opto-electrical photodetector (photodiode 6, 16) interacts optically with the coupling-out end 7, 15 of the optical transmission medium (optical waveguide 8, 30) and its output signal is fed to the input 4, 26 of the amplifier 2, 17. In order to develop the receiver so that it can be used in simple fashion at any points in optical communications systems, so that it is designed in simple and robust form and can function without expensive optical attenuation components, the matching resistor (negative feedback resistor 5; resistor 20 connected in parallel with the amplifier input 26) is designed as a photosensitive component ...

Cct preventing switching clicks - designed esp. for amplifier switching on using voltage divider in amplifier

A voltage divider is brought within the amplifier to suppress switching clicks. The divider consists of a photoresistor and of an ordinary resistor; the photoresistor being placed in a light-tight chamber opposite a light source, e.g. a light emitting diode, connected to a voltage source switched together with the amplifier, provided wtih a delayed switching off; or the light source is connected through a switch to the amplifier voltage source. The above delay is produced by a capacitor connected to the amplifier supply wire. The circuit will be especially valued in tape recorder and sound film camera amplifier's where clicks are usually recorded with the desired sound.

Verfahren zur Beeinflussung des Verstaerkungsgrades eines verstaerkenden Halbleiter-Bauelementes

Schaltung zum Erzeugen eines ansteigenden und nach Erreichen eines vorgegebenen Wertes bis zum Durchfuehren einer Messung konstant bleibenden Stromes durch einen zur Messschaltung gehoerenden Verbraucher

Improvements in or relating to circuit arrangements employing photo-electric devices

... 1,022,307. Photo-electric communication devices. SIEMENS &HALSKE A. G. April 1, 1964 [April 1, 1963; Dec. 20, 1963 (2); Jan. 27, 1964, No. 13349/64. Heading G1A. The invention relates to amplifying, modulating, and signal transmission devices employing a radiation link. In a simple device a photo-emissive diode polarized in the forward direction and modulated by the input signal is used as the radiation source. It may emit substantially monochromatic light. A photo-diode biased in the reverse direction and feeding the output load is used as the receiver. Power gains greater than unity are possible so the device may be used as an amplifier. To avoid bias current flow through the input source or output load it is preferred to separate the bias and signal circuits as is shown for the radiation source side only in Fig. 4. The bias is conveniently made adjustable. Cooling of the photo-emissive diode to the temperature of liquid nitrogen may be arranged to increase the amplifcation. A structural ...

Improvements in or relating to tuned circuits employing transistors

1,119,708. Transistor amplifying and oscillating circuits; remote control of radio receivers. PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd. 15 Oct., 1965 [15 Oct., 1964; 13 Feb., 1965], No. 43799/65. Headings H3Q and H3T. An R.C. coupled transistor circuit which can be adjusted to act as either a high Q circuit or alternatively as an oscillator comprises a first transistor T 1 with its collector connected to the base of a second transistor T 2 . A phase-shifting feedback loop is provided between a further electrode of the second transistor and one of the first transistor, e.g. the network C, R 1 , R 2 connected between the emitters; the arrangement is characterized in that the collector circuit of the first transistor T 1 includes at least two semi-conductor diodes D 1 , D 2 connected in series and arranged in the same direction of conduction as transistor T 1 . The collector circuit also comprises phase-shifting elements, e.g. capacitor C 5 such as to cause a phase-shift equal to but of opposite sign to that of the feedback network at the resonance frequency of the circuit, which is also arranged so that at that frequency the loop gain is substantially equal to unity. The Specification gives mathematical expressions for the necessary conditions, which comprise the inclusion in the collector circuit of transistor T 1 of series resistor R 5 of value double the emitter input resistance of transistor T 2 : each of the diodes D 1 , D 2 should have the same value of differential resistance as the emitter input resistance of transistor T 1 , and this can be varied so as to change the resonance frequency of the circuit by adjustment of the emitter-collector current, by means of resistor R 1 . The value of capacitor C 5 determines the effective Q of the circuit; it is approximately half C, lesser values making Q negative, i.e. causing sustained oscillations to occur. The Specification describes numerous modifications to the circuit, including means for maintaining the ...

Amplifier circuit and recording and reproducing device incorporating the amplifier circuit

... 1,110,986. Gain control. INTERNATIONAL BUSINESS MACHINES CORPORATION. 7 Dec., 1966 [30 Dec., 19651, No. 54786/66. Heading H4R. An electro-luminescent device arranged to luminesce at a predetermined threshold value is connected to the output of an amplifier and a photo-electric device is arranged to receive light from the luminescent device and by its incorporation in the amplifier circuit to effect compression of the signal. In the dictation machine described the output from a threestage transistor amplifier is, during recording, applied to an electro-luminescent device which is coupled to control photo-conductors providing negative feed-back in two of the stages, and is extended outside of a light-tight housing to give an indication when the threshold is exceeded. More than one photo-conductor circuit may be provided for each stage. They may deal differently by reason of their time constants with different frequency ranges or they may be selectable to deal with either speech or music.

Improvement with the automatic control devices of profit of a transistor amplifier.

SWITCHING CONFIGURATION FOR A MEANS OF A STEUERGROESSE CONTROLLABLE ONE AN ELECTRONIC RESISTANCE

SIGNAL LEVEL AUTOMATIC CONTROLLER, IN PARTICULAR FOR THE STUDIO TECHNOLOGY AND FOR THE REMOTE CONTROL TECHNOLOGY

SCHALTUNGSANORDNUNG FUER EINEN MITTELS EINER STEUERGROESSE STEUERBAREN ELEKTRONISCHEN WIDERSTAND

SWITCHING CONFIGURATION FOR A MEANS OF A STEUERGROESSE CONTROLLABLE ONE AN ELECTRONIC RESISTANCE

Einrichtung zur Verstärkung und/oder Modulation, insbesondere für sehr kurze elektromagnetische Wellen

Schaltungsanordnung zum Erzeugen eines auf einen vorgegebenen konstanten Wert ansteigenden Stromes

Verstärkungsschaltungsanordnung zur Erzielung eines praktisch konstanten Wertes einer elektrischen Ausgangsgrösse

Aufzeichnungs- und/oder Wiedergabegerät für elektrische Signale

Photoelektrische Steuervorrichtung und Verwendung derselben

Frequenzmessgerät zur Anzeige von Momentanwerten der Frequenz einer Impulsreihe, insbesondere für medizinische Zwecke

Dispositif destiné à convertir un signal d'entrée en un signal électrique de sortie

Regelschaltung für elektrische Verstärker

SWITCHING CONFIGURATION FOR A CONTROLLABLE ELECTRONIC RESISTANCE.

Automatic control circuit of profit

Improvements in or relating to thermionic amplifiers and control means for use in connection therewith

... 380,499. Valve amplifying circuits. MARCONI'S WIRELESS TELEGRAPH CO., Ltd., Marconi House, Strand, and ROUND, H. J., Westfield, Muswell Hill, both in London. June 17,1931, No. 17614. [Class 40 (v).] The gain of a thermionic amplifier comprising a pentode valve is regulated by a control resistance in t h e screen-grid circuit, consisting wholly or in part of a photoelectric device activated by a controllable light source As shown in the Figure applied to an amplifier circuit similar to that described in Specification 378,950, a selenium cell S is connected in series with a resistance R3 across a supply battery B1. The junction of the cell S and the resistance R3 is connected to the screen-grid of the valve V1, so that the voltage on this grid, which determines the gain, is varied by varying the illumination of the cell S. For this purpose, a lamp EL may be used, and its brightness varied by a rheostat. When the amplifier is used for sound film reproduction, a volume-controlling record film ...

Arrangement for Controlling the Resistance Value of Environment Sensitive Resistance Devices

... 1,194,925. Magneto sensitive switching circuits. ELECTRONIX TEN Inc. 21 Sept., 1967, No. 43062/67. Heading H3T. [Also in Division G1] An arrangement for varying the resistance of a magneto-sensitive resistance device comprises means for generating an energy-field located to influence the resistance device and a power source for the field generator, and is characterized in having a resistor in series between the source and the generator for maintaining the field at a threshold value together with current control means shunted across the series resistor for raising the state of energization of the field generator to the degree required for setting the field-sensitive resistance device to a desired valve. A magnetizing winding producing a field through a magnetoresistance device is exemplified, the current control device across the series resistor comprising a short-circuiting switch or a switch in series with a resistor with a parallel capacitor to provide a surge to enhance the switching ...

Recording and/or Playback Apparatus

... 1,196,647. Automatic volume and tone concontrol. PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd. 29 Sept., 1967 [4 Oct., 1966], No. 44396/67. Heading H4R. A recording and/or playback amplifier Fig. 4 includes a low pass filter 12 having a circuit element, e.g. lamp 18, whose impedance depends on signal level so that the cut off frequency of the filter is reduced as the signal level reduces, to reduce the disturbing effects of high frequency noise components. The filter may alternatively be formed by a series negative temperature coefficient resistor and a shunt capacitor. As shown the lamp 18 is also used to provide automatic gain control by varying the resistance of the photo sensitive resistor 20 in the negative feedback path 19 of the amplifier.

SIGNALPEGELREGLER, INSBESONDERE FUER DIE STUDIOTECHNIK UND FUER DIE FERNSTEUERTECHNIK

CONTROLLABLE ELECTRONIC RESISTANCE

L'invention concerne une résistance électronique contrôlable. Le montage de l'invention comprend un diviseur de tension ST comportant une première résistance R1 et une deuxième résistance R2 commandée par une grandeur de commande S, la prise de ce diviseur étant raccordée à l'entrée d'un amplificateur V dont la sortie est raccordée, via une troisième résistance R3, à une extrémité du diviseur de tension ST dont les deux extrémités forment les bornes de la résistance électronique RS1. L'invention est utilisée pour élever la limite de puissance admissible et l'affaiblissement de distorsion harmonique d'une résistance électronique. The invention relates to a controllable electronic resistance. The assembly of the invention comprises a voltage divider ST comprising a first resistor R1 and a second resistor R2 controlled by a control quantity S, the tap of this divider being connected to the input of an amplifier V whose output is connected, via a third resistor R3, to one end of the voltage divider ST, the two ends of which form the terminals of the electronic resistor RS1. The invention is used to raise the allowable power limit and the harmonic distortion loss of an electronic resistor.

Magnetic verification system for bill acceptor

A magnetic verification system for bill acceptor including a magnetic induction circuit, a signal amplifying and regulating circuit, and a magnetic field generating circuit, the signal amplifying and regulating circuit having a D/A converter, the magnetic induction circuit having a magnetic device adapted for scanning the magnetic ink of the bill to be verified, the magnetic device being adapted to write a magnetic field reference value from the magnetic field generating circuit into the D/A converter, for enabling the D/A converter to adjust the intensity of light being emitted by a LED of the signal amplifying and regulating circuit onto a photoresistance of the signal amplifying and regulating circuit so as to cause the photoresistance to change the resistance thereof subject to the intensity of light from the LED, so that an operation amplifier at the output end of the magnetic induction circuit obtains the correct magnetic field signal value to verify the authenticity of the inserted bill.

A transresistance amplifier for a charged particle detector, possessing a photo-controlled continuously variable input resistance

A charged particle detector in an electron microscope comprises a preamplifier with a continuously variable current-to-voltage converting input resistance formed by a CdS or CdSe photoconductor, a photodiode, a phototransistor or a photoFET IC3. Optical control of the input resistance allows the use of a fixed gain buffer amplifier IC1 and eliminates step changes in bandwidth. The photo-FET opto-coupler may be cascaded after a photo-BJT to improve isolation of the particle detector (figure 2). The control circuit may possess a logarithmic response (IC6, figure 3) to overcome the exponential response of the photo-FET.

LOUD SPEAKING TELEPHONE CIRCUITS

... 1,207,339. Loud-speaking telephones. STANDARD TELEPHONES & CABLES Ltd. 7 Dec., 1967, No. 55740/67. Headings H4K and H4R. In a loud-speaking telephone in which the signal levels in the incoming and outgoing channels are compared and the gains in the two channels differentially varied to favour the channel with the greater signal level A.G.C. is provided over the loud-speaker amplifier by the circuit of Fig. 2 in which a lamp 25 is fed with the loud-speaker amplifier output and illuminates a photo-sensitive resistor 56 controlling the bias on the base of a transistor T2 connected as one element of a potentiometer in the amplifier input. A further transistor 52 provides a variable amount of negative feedback over transistor T1 in the amplifier, the control potential for the transistor 52 being derived from the switching circuit (8, Fig. 1, not shown). The loud-speaker switching amplifier (10, Fig. 1) is fed via lead 38 with the loud-speaker channel signal after its amplitude has been stabilized ...

SIGNAL LEVEL AUTOMATIC CONTROLLER, IN PARTICULAR FOR THE STUDIO TECHNOLOGY AND FOR THE REMOTE CONTROL TECHNOLOGY

METHOD AND APPARATUS FOR PROCESSING A DIGITAL SIGNAL FOR CONTROLLING AT LEAST ONE POTENTIOMETER

L'objet selon la présente invention concerne un circuit électronique de contrôle (100) permettant le traitement d'un signal numérique de contrôle (SN) afin de contrôler d'au moins un potentiomètre (P), ledit circuit électronique de contrôle (100) comportant : - un moyen de distorsion (10) configuré pour distordre le signal de contrôle (SN) en fonction d'au moins une donnée de distorsion (DD) prédéterminée, - un moyen de conversion (20) configuré pour convertir ledit au moins un signal numérique distordu (SN') en un signal analogique (SA), et - au moins un optocoupleur (30) configuré pour coupler ledit signal analogique (SA) afin d'isoler galvaniquement le circuit électronique de contrôle (100) et ledit au moins un potentiomètre (P).

Control device of an electronic amplifier in particular for accordions

Fittings of checking circuits of attenuation and profit

Verfahren zur Erzeugung von Abklingvorgaengen

GESTEUERTE WIDERSTANDSANORDNUNG

Frequenzmessgeraet zur Anzeige von Momentanwerten der Frequenz einer Impulsreihe,insbesondere fuer medizinische Zwecke

Improvements in transistor circuits

... 940,672. Transistor amplifiers. PYE Ltd. April 28, 1961 [May 13, 1960], No. 16962/60. Heading H3T. [Also in Division G1] The gain of a transistor amplifier is controlled from a remote point by connecting a lightsensitive or heat-sensitive resistive element in parallel with the emitter resistor R1 and controlling the value of the resistive element by means of an electric lamp or heating element energized by a voltage which is variable at the remote point. Adjustment of potentiometer R3 at the remote point varies the intensity of the lamp LP and hence the resistance value of the photo-conductor PC, thus varying the negative feedback provided in the emitter circuit of the transistor and hence the gain of the amplifier.

Compandor

... 967,152. Compandors operated photo-electrically. STANDARD TELEPHONES & CABLES Ltd. April 5, 1963 [April 11, 1962], No. 13691/63. Heading G1A. [Also in Division H4] The invention relates to an amplitude compression and/or expansion arrangement for voicefrequency electrical signals in a communication system, comprising a variable loss network including a photo-electric element, a source of light acting upon said element and means to modulate said source of light in accordance with the syllabic rate of said voice frequency signals. By "syllabic rate" is meant the rate at which the syllables of speed follow each other and is generally about 10 to 100 per second. In the embodiment shown in Fig. 7 speech signals to be sent from an OFFICE 1 to OFFICE 2, derived from a two wire line 51 are fed through a hybrid coil 54 with balancing network 55 to a transmitting amplifier 56 in a compressor circuit. The output of amplifier 56 is fed back through a summing circuit 61 and an amplifier 62 to a lamp ...

Frequency Measuring Apparatus

... 1,165,498. Frequency measurement. F. HOFFMANN-LA ROCHE & CO. A.G. 6 May, 1968 [12 May, 1967 (2)], No. 21377/68. Heading G4H. [Also in Division H3] Apparatus for measuring the instantaneous frequency of electrical pulses representing for example heart beat frequency includes an amplifier circuit 2 (see Division H3) delivering a constant amplitude output pulse for each input pulse, the first pulse enabling a gate 13 to pass clock pulses at, e.g. 1 kc/s. to a first counter 17, the second pulse closing gate 13 and enabling a gate 14 to pass clock pulses at e.g. 100 kc/s. to a second counter 18, the outputs of the counter being compared and a pulse fed to decade counter 27 at equality. This pulse resets counter 18 and the process is repeated until a predetermined number of pulses, e.g. 60,000 have been fed via gate 14, a counter-29 also receiving these pulses then closing gate 14. The number of times counter 18 is reset, i.e. the count in counter 27, represents the instantaneous frequency. This ...

Improvements in or relating to variable attenuators

... 1,096,665. Gain control; transistor circuits. MARCONI CO. Ltd. Feb. 8, 1966 [April 2, 1965], No. 14108/65. Headings H3T and H4R. [Also in Divisions G1 and H2] A variable attenuator comprises a photoresistor illuminated by a plurality of lamps controlled so that for decreasing attenuation one is brought substantially to full intensity before another is appreciably energized. The lamps 4, 5 are fed from a constant current source 6, 7, 8, the current supplied thereby being controlled by a potentiometer 9. At low currents, the Zener diode 17 blocks energization of lamp 5 and lamp 4 is only slightly energized through the transistor 15. As the current from source 6, 7, 8 increases the current through lamp 4 increases until the lamp is fully energized, further current increase being bled off by diodes 12 and 13. At this current level, too, the Zener diode 17 conducts, and as the current from source 6, 7, 8 further increases more and more current flows through lamp 5 until both lamps are fully ...

Improvements in electrical circuits

... 1,142,880. Measuring blood pressure. INTERNATIONAL BUSINESS MACHINES CORP. 19 Sept., 1966 [20 Oct., 1965], No. 41653/66. Heading ASK. [Also in Division G3] A blood pressure measuring system includes a circuit for periodically establishing a predetermined voltage for a predetermined period across a device such as a thermistor or, as shown, a photocell 12, the circuit comprising a series transistor Tl connected to control the photocell current, a capacitor C for applying a variable control voltage starting at a datum level to the transistor Tl, and a detector, e.g. a Schmitt trigger 20, operable when the voltage across the photocell 12 is equal to the said predetermined voltage to prevent further variation of the control voltage. In the embodiment shown the photoelectric cell 12 is incorporated in a blood pressure measuring transducer 10, 11 and the current in photocell 12 is set to give the desired voltage output prior to each blood pressure measurement. Thus, under the control of circuit ...

Frequency measuring instrument to the announcement of instantaneous values of the frequency of a train of impulses, in particular for medical purposes

HEADPHONE AUTOMATIC GAIN CONTROL SYSTEM

Adjustable impedance, in particular adjustable resistance

Device of compression or expansion of the dynamics of a signal

RECEIVER GAIN CONTROL SYSTEM PROVIDING NEGATIVE RESISTANCE STABILIZATION

Programmierbare Steuerungen für Vakuumröhrenverstärker

Patent DE3728616C2

Control circuit for setting predetermined resistance values and resistance value ratios in photoresistors (photoconductors, photoconductive cells)

The invention serves to set photoresistance values exactly. The resistance value is determined either by external circuit elements of the control circuit or by an electrical reference variable. As a result, it is possible to simulate by means of photoresistors a potentiometer which works in a potential-free manner and whose total resistance value is determined by a reference resistance of the same magnitude and whose part resistance ratio is determined by a reference voltage independently of the total resistance value. The photoresistance value is set by means of a filament lamp. The control is made possible by matching the controlled system. The matching is performed by a delogarithmising and inverting of the controlled system, as well as the displacement of the filament lamp voltage by a residual value, so that the light emission of the filament lamp cannot drop below a minimum.

Einrichtung zur Amplitudenmodulation von Tonfrequenzspannungen und ihre Anwendung bei einer Verstaerkerschaltung

Improvements in or relating to variable attenuators

... 1,074,668. Variable attenuator. TELEFUNKEN PATENTVERWERTUNGS G.m.b.H. Feb. 8, 1966 [Feb. 8, 1965], No. 5489/66. Heading H4R. A variable attenuator which includes a photoresistive element illuminated by a controlled light source to control the attenuation has a constant D.C. voltage applied to the attenuator in addition to the A.C. signal to be attenuated. The attenuated D.C. voltage is compared with a control voltage and the difference used to adjust the illumination from the light source. The Figure shows a system in which a D.C. voltage developed across Zener diode 8 is applied to the input of an attenuator I together with the alternating input signal. The output of the attenuator, together with a fixed D.C. bias from Zener diode 7, is applied to a D.C. amplifier, including transistors 10 to 13, which, due to its negative feedback connection, has a low A.C. input impedance so that the A.C. signal output of the attenuator I is attenuated in resistor 19 and does not affect the control function ...

Apparatus of recording and reproduction of electrical signals

FREQUENCY?MEASURING APPARATUS FOR THE INDICATION OF MOMENTARY VALUES OF THE FREQUENCY OF A SERIES OF IMPULSES, ESPECIALLY FOR MEDICAL PURPOSES

Resonant circuit to two transistors

Improvements with the automatic control devices of profit of a amplificateurà transistors

CIRCUIT FOR [...] OF aMPLITUDE OF A lOW FREQUENCY SIGNAL

Process allowing to vary automatically the amplification of one or more electron tubes according to variations of illumination

DIGITAL SIGNAL PROCESSING TO CONTROL AT LEAST ONE POTENTIOMETER

The present invention relates to an electronic control circuit (100) enabling a digital control signal (SN) to be processed in order to control at least one potentiometer (P), said electronic control circuit (100) electrically connected to said at least one potentiometer (P) comprising: a distortion circuit (10) configured to distort said signal (SN) in accordance with at least one predetermined distortion datum (DD) in order to obtain two distorted digital signals (SN1', SN2'); a conversion circuit (20) configured to convert each distorted digital signal (SN1', SN2') respectively into first (SA1) and second (SA2) analog signals; a filtering circuit (30) configured to apply a low-pass filter to each analog signal (SA1, SA2); a coupling circuit (30) including two optocouplers (OPT1, OPT2) configured to couple the filtered analog signals (SA1', SA2') and to galvanically insulate the electronic control circuit (100) and said at least one potentiometer (P).

Implementing enhanced CMOS inverter based optical transimpedance amplifier

A method and circuit are provided for implementing enhanced CMOS inverter based optical Transimpedance Amplifiers (TIAs). A transimpedance amplifier(TIA) includes a photo- detector, and the TIA is formed by a first TIA inverter and a second TIA inverter. The first TIA inverter has an input from a cathode side of the photo-detector and the second inverter has an input from an anode side of the photo-detector. A replica TIA is formed by two replica inverters, coupled to a respective input to a first operational amplifier and a second operational amplifier. The first operational amplifier and the second operational amplifier have a feedback configuration for respectively regulating a set voltage level at the cathode side of the photo-detector input of the first inverter and at the anode side of the photo- detector input of the second inverter ...

Improvements in or relating to Transistor Amplifiers for High Frequency

... 1,164,682. Automatic gain control of amplifiers. TELEFUNKEN PATENTVERWERTUNGS G.m.b.H. 8 March, 1967 [16 March, 1966], No. 10946/67. Heading H3T. The input signal of a tuned high frequency transistor amplifier is prevented from reaching an excessive level by means of a light sensitive damping device connected across the input circuit and illuminated by light controlled by the input signal. In the radio receiver shown a photo resistor is connected across the primary or secondary of the input transformer 12 or across the input of the frequency changer 15. If the input signal is excessive a lamp 10 controlled by the A.G.C. line reduces the resistance of the photo-resistor and thus the amplitude of the signal. An amplifier may be connected in the A.G.C. line and the photo-resistor may be connected in series with the tuned circuit in which case its resistance must increase when the signal is excessive.

ACTIVE APD GAIN CONTROL FOR AN OPTICAL RECEIVER

An active avalanche photo-diode, APD, gain control circuit for use in an optical receiver includes a bias generator for varying the bias on a variabl e gain APD in response to bias control values generated by a controller. The controller re ceives the output of the optical receiver and determines the system noise of the receiv er for the various bias control values. The system noise is compared to a threshold val ue for establishing the optimum bias for optimum gain of the APD. The gain control circuit is useable in an optical receiver in an optical time domain reflectometer, OTDR , for increasing the dynamic range of the OTDR.

Device of compression or expansion of the dynamics of a signal

Circuit having a dynamic ordering of level

Device allowing to obtain an adjustable tension partial starting from the tension of an electrical signal

LOUDSPEAKER TELEPHONE CIRCUIT ARRANGEMENT

Amplifier with ordering of automatic profit

Attenuator control arrangements

An attenuator control arrangement for use in a frequency multiplexed communications system includes a light-dependent attenuating resistance which is controlled in normal operation by the level of a pilot tone, in the multiplexed signal being attenuated, being used to control a light-emitting diode which illuminates the light-dependent resistance. A second light-dependent resistance also illuminated by the light-emitting diode is used to provide a control signal for the light-emitting diode in the event that the pilot tone is not detected, whereby a stable attenuation is provided in the absence of the pilot tone.

Implementing enhanced CMOS inverter based optical transimpedance amplifier

DUAL VOLUME CONTROL CIRCUIT

... 1,260,809. Gain control. WESTINGHOUSE ELECTRIC CORP. 22 May, 1970 [27 May, 1969], No. 24812/70. Headings H3Q -and H4R. A volume control system includes a first circuit with a master variable impedance element and a second circuit including a light responsive variable impedance element connected between a source of audio signals and an amplifier where the intensity of a light source is varied from a remote position to provide a volume control. The master variable impedance element is the variable resistor R2 forming part of the potential divider R1, R2 and will vary the signal applied to the control grid of pentode V1. The second circuit comprises a potential divider formed by resistor R3 and light sensitive resistor R4 which is housed together with lamp X1 in box 12. The intensity of illumination of the lamp is altered by means of resistor R8 to give a variation of resistance of R4 from 100 M# (dark) to less than 0À1 M# (light) thus altering the attenuation of the input circuit to a considerable ...

Improvements in or relating to photorheostats

... 1,128,593. Photo-electric variable resistors. COMPAGNIE INDUSTRIELLE FRANCAIS DES TUBES ELECTRONIQUES. Jan. 31, 1966 [Feb. 5, 1965], No.4112/66. Heading G1A. [Also in Division H1] A voltage controlled resistor comprises a discharge tube 5, a photo-resistor 2 and a screen 8. The tube 5 has filiform anode and cathode 6, 7 and is so designed that at the lowest voltage that will support a discharge the cathode glow extends along a length G1 and thus cannot illuminate the photo-resistor 2 directly, but only by diffusion. As the voltage increases the glow spreads over more of the cathode and more light falls directly on to the photo-resistor. In modifications the cathode may be longer than the anode, Fig. 2 (not shown) or the tube may be A.C. energized with the screen extending along only the middle of the tube 5, Fig. 3 (not shown). The characteristic of the resistor may be controlled by suitable shaping of the photo-resistor Figs. 4, 5 and 6 (not shown). A plurality of photo-resistors may be ...

Improvements in control arrangements for electrical amplifiers

... 904,031. Controlling gain photo-electrically. PHILIPS ELECTRICAL INDUSTRIES Ltd. Nov. 21, 1958 [Nov. 26, 1957; May 8, 1958], No. 37559/58. Class 40 (3). [Also in Group XL (a)] The output of an amplifier 2 controls a light source (a neon glow tube) 6 which reduces the impedance of a photo-sensitive semi-conductor (e.g. cadmium sulphide) shunting the input if the input signal is large enough to overdrive the amplifier. Glass envelopes containing the light source and resistor may be fused together to form a single-unit (Fig. 2, not shown), or they may be in a cylindrical envelope 31 provided with a mesh 30 which allows passage of light from the glow tube 6 to the photo-register 4 while preventing capacitive transfer of voltage pulses from the one to the other.

Improvements in or relating to electric control elements

... 879,949. Light controlled potentiometers. PHILIPS ELECTRICAL INDUSTRIES Ltd. March 6, 1958 [March 9, 1597], No. 7250/58. Class 40(3) [Also in Group XXXVI] In an adjustable voltage dividing device, the input voltage V1, Fig. 1, is applied across a fixed resistance 5 and a light sensitive resistance 6 (see Group XXXVI) connected in series and the output voltage Vu is varied by varying the light incident on the light sensitive resistor. Various methods of varying the light are described, e.g. varying the light source intensity, Fig. 5 (not shown), applying the light via a rotatable disc of varying density or applying the light via a fixed aperture and a rotatable aperture, Figs. 3 and 4, (not shown), which may be formed in various shapes to provide a variety of potentiometer laws. In a further arrangement, Fig. 6, the input is applied to two light sensitive resistors 6, 60 connected in series and the incident light is arranged so that one resistor receives more illumination when the other ...

System and method for varying low audio frequencies inversely with audio signal level

ACTIVE APD GAIN CONTROL FOR AN OPTICAL RECEIVER

An active avalanche photo-diode, APD, gain control circuit for use in an optical receiver includes a bias generator for varying the bias on a variable ga in APD in response to bias control values generated by a controller. The controller receiv es the output of the optical receiver and determines the system noise of the receiver f or the various bias control values. The system noise is compared to a threshold value f or establishing the optimum bias for optimum gain of the APD. The gain control circ uit is useable in an optical receiver in an optical time domain reflectometer, OTDR, fo r increasing the dynamic range of the OTDR.

PHOTOELECTRIC VOLTAGE CONTROL CIRCUIT

CONTROLLABLE ELECTRONIC RESISTANCE DEVICE

Control device of profit applicable in particular to the compressors-expanseurs

A method for causing processes of extinction

Device of cutting of electric quantities to continuous characteristic

Regulating device and separate regulating element, for electric amplifiers

Device to amplify and modulate electric waves

CIRCUIT FOR [...] OF aMPLITUDE OF A lOW FREQUENCY SIGNAL

Digital vol. adjustment circuit for audio amplifier - has photoresistor as vol. adjuster in input circuit of inverting operational amplifier

The amplifier is controlled via a D/A converter. In the input circuit of an inverting operational amplifier (OP2) is incorporated a photoresistor (PH) as adjusting element for the vol. setting. It is fitted in the effective range of at least one light emitting elementm (LED). Pref. the current for the LEDs is generated by a digital, current controlled current source, forming simultaneously the D/A converter. The digital current control may be carried out by current summation at the current source input. The circuit may contain an EPROM for correction values for the characteristic of an opto-coupler. -ADVANTAGE - No cracking noise and distortion of output signal.

Regelschaltung und Schaltelement fuer elektrische Verstaerker

Regelschaltung fuer seismische Verstaerker

Improvements in transistorised amplifiers

... 1,126,958. Transistor amplifying circuits. COMPAGNIE FRANCAISE THOMSON HOUSTON-HOTCHKISS BRANDT. 20 May, 1966 [21 May, 1965], No. 22584/66. Headings H3T and H4F. In a transistorized amplifier having at least two amplifier stages T1, T2 and a potentio. metric chain of impedances R1, R2 providing a negative feedback path from one stage to an earlier stage, a variable condition external to the amplifier causes a corresponding electrical signal to be produced which serves to vary the effective impedance of one of the impedances in the chain to vary the degree of feedback. As shown, resistor R1 is shunted for A.C by the collector-emitter impedance of an auxiliary transistor T3 which is varied by variation of the base bias by means of a potentiometer comprising resistor R6 and photo-diode D. The arrangement may be used for the automatic regulation of contrast and brilliance of the image in a television receiver in accordance with the ambient illumination.

RESISTANCE ELECTRONIQUE CONTROLABLE

L'invention concerne une résistance électronique contrôlable. Le montage de l'invention comprend un diviseur de tension ST comportant une première résistance R1 et une deuxième résistance R2 commandée par une grandeur de commande S, la prise de ce diviseur étant raccordée à l'entrée d'un amplificateur V dont la sortie est raccordée, via une troisième résistance R3, à une extrémité du diviseur de tension ST dont les deux extrémités forment les bornes de la résistance électronique RS1. L'invention est utilisée pour élever la limite de puissance admissible et l'affaiblissement de distorsion harmonique d'une résistance électronique.

Electric device of adjustment for seismic amplifiers

Stabilizing device of tension

Gain control for an optical receiver

An active avalanche photo-diode, APD, gain control circuit for use in an optical receiver includes a bias generator for varying the bias on a variable gain APD in response to bias control values generated by a controller. The controller receives the output of the optical receiver and determines the system noise of the receiver for the various bias control values. The system noise is compared to a threshold value for establishing the optimum bias for optimum gain of the APD. The gain control circuit is useable in an optical receiver in an optical time domain reflectometer, OTDR, for increasing the dynamic range of the OTDR.

TRANSRESISTANZVERSTÄRKER FÜR EINEN DETEKTOR FÜR GELADENE TEILCHEN

TRANSISTORISIERTER VIDEO VERSTERKER MIT SELBSTSTAENDIGER KONTRAST UND HELLIGKEITSREGELUNG IN ABHAENGIGKEIT VON DER RAUMHELLIGKEIT

Schaltungsanordnung fuer ein Photometer

BURST MODE TRANS-IMPEDANCE AMPLIFIER

The present invention provides a burst mode trans-impedance amplifier, comprising: a voltage input circuit, used for sensing an optical signal and converting the optical signal into an input voltage signal; a differential circuit, having two input ends and an output end, wherein one input end is coupled to the voltage input circuit and is used for receiving the input voltage signal, the other input end is coupled to a threshold voltage signal, and the output end is used for regulating and outputting a differential voltage signal according to the input voltage signal and the threshold voltage signal; and a feedback regulation circuit, having an input end and an output end, wherein the input end is coupled to the output end of the differential circuit and is used for receiving the differential voltage signal, and the output end is coupled to the voltage input circuit. 1. A burst mode trans-impedance amplifier , comprising:a voltage input circuit, sensing an optical signal and converting the optical signal into an input voltage signal;a differential circuit, having two input ends and an output end, wherein one input end is coupled to the voltage input circuit and is used for receiving the input voltage signal, the other input end is coupled to a threshold voltage signal, and the output end is used for regulating and outputting a differential voltage signal according to the input voltage signal and the threshold voltage signal; anda feedback regulation circuit, having an input end and an output end, the input end being coupled to the output end of the differential circuit and used for receiving the differential voltage signal, the output end being coupled to the voltage input circuit and used for outputting a voltage regulation signal to the voltage input circuit according to the differential voltage signal.2. The burst mode trans-impedance amplifier according to claim 1 , wherein the voltage input circuit comprises:an optical diode, used for receiving the optical ...

IMPLEMENTING ENHANCED CMOS INVERTER BASED OPTICAL TRANSIMPEDANCE AMPLIFIER

A method and circuit are provided for implementing enhanced CMOS inverter based optical Transimpedance Amplifiers (TIAs). A transimpedence amplifer (TIA) includes a photo-detector, and the TIA is formed by a first TIA inverter and a second TIA inverter. The first TIA inverter has an input from a cathode side of the photo-detector and the second inverter has an input from an anode side of the photo-detector. A replica TIA is formed by two replica inverters, coupled to a respective input to a first operational amplifier and a second operational amplifier. The first operational amplifier and the second operational amplifier have a feedback configuration for respectively regulating a set voltage level at the cathode side of the photo-detector input of the first inverter and at the anode side of the photo-detector input of the second inverter. 18-. (canceled)9. A circuit for implementing an enhanced bias configuration for CMOS inverter based optical Transimpedance Amplifiers (TIAs) comprising:a transimpedence amplifer (TIA) including a photo-detector, and the TIA being formed by a first TIA inverter and a second TIA inverter;said first TIA inverter having an input from a cathode side of said photo-detector and said second TIA inverter with an input from an anode side of said photo-detector;a respective output of said first TIA inverter and said second TIA inverter coupled to a respective input of a first operational amplifier and a second operational amplifier; andsaid first operational amplifier and said second operational amplifier in a feedback configuration for respectively biasing a set voltage level at said cathode side photo-detector input to said first TIA inverter and at said anode side photo-detector input of said second TIA inverter.1020-. (canceled)21. The circuit as recited in includes a P-channel field effect transistor (PFET) connected between a voltage rail VDD and the cathode side of the photo-detector input of said first TIA inverter.22. The circuit as ...

Implementing enhanced cmos inverter based optical transimpedence amplifer

A method and circuit are provided for implementing enhanced CMOS inverter based optical Transimpedance Amplifiers (TIAs). A transimpedence amplifer (TIA) includes a photo-detector, and the TIA is formed by a first TIA inverter and a second TIA inverter. The first TIA inverter has an input from a cathode side of the photo-detector and the second inverter has an input from an anode side of the photo-detector. A replica TIA is formed by two replica inverters, coupled to a respective input to a first operational amplifier and a second operational amplifier. The first operational amplifier and the second operational amplifier have a feedback configuration for respectively regulating a set voltage level at the cathode side of the photo-detector input of the first inverter and at the anode side of the photo-detector input of the second inverter.

AMPLIFIER CIRCUIT

An amplifier circuit includes: an operational amplifier that includes two input terminals and an output terminal; a voltage-dividing resistor circuit electrically connected to the output terminal and that includes a voltage-dividing terminal that outputs a potential obtained by voltage-dividing a potential of the output terminal and a feedback resistor circuit electrically connected to the voltage-dividing terminal and one of the two input terminals. The voltage-dividing resistor circuit includes a plurality of resistors that each include terminals and a switch. The plurality of resistors includes a first resistor and a second resistor. The first resistor includes a terminal that corresponds to the voltage-dividing terminal. The switch switches, from a first terminal of the first resistor to a second terminal of the second resistor, the terminal that corresponds to the voltage-dividing terminal. 1. An amplifier circuit , comprising:an operational amplifier that comprises two input terminals and an output terminal; 'a voltage-dividing terminal that outputs a potential obtained by voltage-dividing a potential of the output terminal; and', 'a voltage-dividing resistor circuit electrically connected to the output terminal and that comprisesa feedback resistor circuit electrically connected to the voltage-dividing terminal and one of the two input terminals, wherein a plurality of resistors that each comprise terminals; and', 'a switch,, 'the voltage-dividing resistor circuit comprisesthe plurality of resistors comprises a first resistor and a second resistor,the first resistor comprises a terminal that corresponds to the voltage-dividing terminal, andthe switch switches, from a first terminal of the first resistor to a second terminal of the second resistor, the terminal that corresponds to the voltage-dividing terminal.2. The amplifier circuit according to claim 1 , whereinthe voltage-dividing resistor circuit further comprises a first switch and a second switch, ...

Gear change, located in the crankset for cycles and cyclo-motors

Photorheostat

A resonant circuit provision that includes at least two transistors. (Machine-translation by Google Translate, not legally binding)

A resonant circuit arrangement that includes at least two transistors with emitters, bases and collectors, in which the collector of the first transistor is connected to the base of the second transistor, a phase shifter feedback coupling being provided between at least one of the remaining electrodes of the second transistor and that of the first transistor, characterized in that the collector circuit of the first transistor includes the series combination of at least two semiconductor diodes polarized in the direction of passage, serial combination to which phase shifting elements are connected such that the phase shift of the collector of the first transistor to the base of the second transistor and that of the phase-shifting feedback coupling are the same but of opposite sign to the resonance frequency of the circuit, while the product of the amplification and the Feedback is at least substantially equal to the unit. (Machine-translation by Google Translate, not legally binding)

Headphone automatic gain control system

An automatic gain control circuit for use with a motorcycle radio and headset features an adjustable control for setting the maximum signal allowed to reach the headset, while allowing normal signal levels below that point to be controlled at the motorcycle radio. The circuit may be easily incorporated for use with a previously installed radio as well as an enhancement for new radio designs. Isolation transformers on both the input and output of the circuit eliminate the necessity to ground the circuit. Bass boost and internal gain circuits compensate for internal losses and headphone loading characteristics to provide near-transparent signal transfer below the set maximum signal level.

Method and device for regulating the gain of an amplifier

Patent JPS4927991B1

Preamplifier gain switching circuit

Amplifier circuit

An amplifier circuit includes: an operational amplifier that includes two input terminals and an output terminal; a voltage-dividing resistor circuit electrically connected to the output terminal and that includes a voltage-dividing terminal that outputs a potential obtained by voltage-dividing a potential of the output terminal and a feedback resistor circuit electrically connected to the voltage-dividing terminal and one of the two input terminals. The voltage-dividing resistor circuit includes a plurality of resistors that each include terminals and a switch. The plurality of resistors includes a first resistor and a second resistor. The first resistor includes a terminal that corresponds to the voltage-dividing terminal. The switch switches, from a first terminal of the first resistor to a second terminal of the second resistor, the terminal that corresponds to the voltage-dividing terminal.

Multiplexed gain control for a synchro data transmission system

A synchro data repeater system is provided with a proportional gain control for compensating for undesirable transmitter signal amplitude variations, the system being particularly adapted for application in magnetic compass systems to compensate for changes in the field strength of the horizontal component of the earth''s magnetic field, especially in high latitude navigation.

Automatic volume control circuit

Transducer device

Controllable electronic resistance device

ABSTRACT An electronic resistance device comprising an amp-lifier having an input and an output and a voltage divider including a first resistor and a second resistor connected in series between a first and second terminal. The amp-lifier input is connected to the junction of the first and second resistors and a third resistor connects the amp-lifier output to the first terminal. The second resistance is adjustable in response to an applied control signal so as to thereby adjust the value of the electronic resistance device.

Amplifier for dictation machines with dynamic compression

Patent FR2212067A5

SYNCHRO DATA TRANSFER DEVICE

Patent JPH0137885B2

Average power limiter

(57)【要約】本公報は電子出願前の出願データであるた め要約のデータは記録されません。

Un aparato de grabacion yno reproduccion para senales elec-tricas.

Implementing enhanced cmos inverter based optical transimpedence amplifer

A method and circuit are provided for implementing enhanced CMOS inverter based optical Transimpedance Amplifiers (TIAs). A transimpedence amplifer (TIA) includes a photo-detector, and the TIA is formed by a first TIA inverter and a second TIA inverter. The first TIA inverter has an input from a cathode side of the photo-detector and the second inverter has an input from an anode side of the photo-detector. A replica TIA is formed by two replica inverters, coupled to a respective input to a first operational amplifier and a second operational amplifier. The first operational amplifier and the second operational amplifier have a feedback configuration for respectively regulating a set voltage level at the cathode side of the photo-detector input of the first inverter and at the anode side of the photo-detector input of the second inverter.

Implementing enhanced CMOS inverter based optical transimpedance amplifier

Implementing enhanced cmos inverter based optical transimpedance amplifier

A method and circuit are provided for implementing enhanced CMOS inverter based optical Transimpedance Amplifiers (TIAs). A transimpedence amplifer (TIA) includes a photo-detector, and the TIA is formed by a first TIA inverter and a second TIA inverter. The first TIA inverter has an input from a cathode side of the photo-detector and the second inverter has an input from an anode side of the photo-detector. A replica TIA is formed by two replica inverters, coupled to a respective input to a first operational amplifier and a second operational amplifier. The first operational amplifier and the second operational amplifier have a feedback configuration for respectively regulating a set voltage level at the cathode side of the photo-detector input of the first inverter and at the anode side of the photo-detector input of the second inverter.

Implementing enhanced cmos inverter based optical transimpedance amplifier

A method and circuit are provided for implementing enhanced CMOS inverter based optical Transimpedance Amplifiers (TIAs). A transimpedance amplifier(TIA) includes a photo- detector, and the TIA is formed by a first TIA inverter and a second TIA inverter. The first TIA inverter has an input from a cathode side of the photo-detector and the second inverter has an input from an anode side of the photo-detector. A replica TIA is formed by two replica inverters, coupled to a respective input to a first operational amplifier and a second operational amplifier. The first operational amplifier and the second operational amplifier have a feedback configuration for respectively regulating a set voltage level at the cathode side of the photo-detector input of the first inverter and at the anode side of the photo- detector input of the second inverter.

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Verstärkungssteuerung für einen optischen Empfänger

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Arrangement for deriving an adjustable partial voltage from an electric signal voltage

Verstärkungssteuerung für einen optischen Empfänger

Dispositivo de mando automatico de ganancia de un amplificador con transistores.

System and method for varying levels of low audio frequences inversely with audio signal level

The invention relates to an auto loudness circuit (350) for performing loudness compensation automatically depending on the signal level. When the signal level decreases, loudness compensation is slowly introduced and as the signal level increases, loudness compensation is quickly removed. To do so, the auto loudness circuit (350) utilizes a filter circuit (430, 530, 545) with the characteristic of a first order bass boost. The filter circuit (430, 530, 545) maintains a corner frequency which is proportional to the inverse of audio level in order to mimic the Fletcher-Munson curves. Because the circuit employs a capacitance-multiplier (530) with a first order resistance capacitance filter, the bass boost is inversely proportional to the signal level. Thus, bass boost is achieved automatically as the program content changes so that the listener is unaware of significant changes in program material as signal levels change either through increase or decrease in volume, crescendo or new material.

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増幅回路及び濁度計

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Schaltungsanordnung zum Schutz der Verstärker gegen Überlastungen in Lautsprecheranlagen

System and method for varying levels of low audio frequences inversely with audio signal level

Schaltungsanordnung zur Regelung der Bildhelligkeit eines Fernsehempfaengers

Anordnung zur Steuerung von Stromverbrauchern in Abhaengigkeit von einer Spannung

Einrichtung zur Modulation

Verstaerkereinrichtung fuer elektro-magnetische Schwingungen

Light-controlled attenuator

A light-controlled attenuator comprises a pair of photosensitive resistance cells mounted facing each other, a pair of spaced parallel optical shutters disposed between the cells, and a single light source situated between the shutters so as to illuminate each cell through a portion of its respective shutter. Each shutter may be opaque except for a transparent aperture of controlled dimensions, or may otherwise vary in optical transmissivity as a function of position on the shutter surface. Means are provided to change simultaneously the portion of the shutters interposed in the light paths to the two cells, the aperture width or density of the interposed shutter portion determining the effective resistance of each cell.

Volumensteuerschaltung

Schaltungsanordnung zum Schutz der Endstufen der Transistorverstärker gegen Überlastungen in Lautsprecheranlagen

Transresistance amplifier for a charged particle detector

Disclosed is a transresistance amplifier for a charged particle detector, comprising a variable input resistance, which may be a phototransistor (IC3), a voltage amplification stage (IC1) and control means (IC3), operable to vary the variable input resistance. The variable input resistance includes a first light-dependent resistance and the control means includes a first variable intensity light source that is optically coupled to the first light-dependent resistance. Also disclosed is a charged particle detector that includes such a transresistance amplifier and an electron microscope that includes such a charged particle detector.

Transresistance amplifier for a charged particle detector

Transresistance amplifier for a charged particle detector

Disclosed is a transresistance amplifier for a charged particle detector, comprising a variable input resistance, which may be a phototransistor (IC3), a voltage amplification stage (IC1) and control means (IC3), operable to vary the variable input resistance. The variable input resistance includes a first light-dependent resistance and the control means includes a first variable intensity light source that is optically coupled to the first light-dependent resistance. Also disclosed is a charged particle detector that includes such a transresistance amplifier and an electron microscope that includes such a charged particle detector.

Verstaerkeranordnung mit fotoelektrischen Koppelelementen

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Procede et dispositif de traitement d'un signal numerique pour le controle d'au moins un potentiometre

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연산증폭기의 이득제한회로

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Photo-electric bias control circuit

Photoelektrisches Potentiometer

Schaltungsanordnung fuer ein sprachgesteuertes Lautfernsprechgeraet

Photoelektrisches potentiometer

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Agencement de resistances commande.

放大器电路

本公开提供了一种放大器电路，包括：运算放大器，该运算放大器包括两个输入端子以及一个输出端子；分压电阻器电路，该分压电阻器电路电连接输出端子并且包括分压端子，该分压端子输出通过对输出端子的电位进行分压而获得的电位；以及反馈电阻器电路，该反馈电阻器电路电连接分压端子以及两个输入端子之一。分压电阻器电路包括多个电阻器以及开关，每个电阻器包括端子。所述多个电阻器包括第一电阻器和第二电阻器。第一电阻器包括与分压端子对应的端子。开关通过从第一电阻器的第一端子切换到第二电阻器的第二端子来切换与所述分压端子对应的端子。

Schaltungsanordnung zur elektronischen verstaerkungseinstellung

Implementing enhanced CMOS inverter based optical transimpedance amplifier

A method and circuit are provided for implementing enhanced CMOS inverter based optical Transimpedance Amplifiers (TIAs). A transimpedence amplifer (TIA) includes a photo-detector, and the TIA is formed by a first TIA inverter and a second TIA inverter. The first TIA inverter has an input from a cathode side of the photo-detector and the second inverter has an input from an anode side of the photo-detector. A replica TIA is formed by two replica inverters, coupled to a respective input to a first operational amplifier and a second operational amplifier. The first operational amplifier and the second operational amplifier have a feedback configuration for respectively regulating a set voltage level at the cathode side of the photo-detector input of the first inverter and at the anode side of the photo-detector input of the second inverter.

Implementing enhanced CMOS inverter based optical transimpedence amplifier

A method and circuit are provided for implementing enhanced CMOS inverter based optical Transimpedance Amplifiers (TIAs). A transimpedence amplifer (TIA) includes a photo-detector, and the TIA is formed by a first TIA inverter and a second TIA inverter. The first TIA inverter has an input from a cathode side of the photo-detector and the second inverter has an input from an anode side of the photo-detector. A replica TIA is formed by two replica inverters, coupled to a respective input to a first operational amplifier and a second operational amplifier. The first operational amplifier and the second operational amplifier have a feedback configuration for respectively regulating a set voltage level at the cathode side of the photo-detector input of the first inverter and at the anode side of the photo-detector input of the second inverter.

Implementing enhanced CMOS inverter based optical transimpedance amplifier

A method and circuit are provided for implementing enhanced CMOS inverter based optical Transimpedance Amplifiers (TIAs). A transimpedance amplifier (TIA) includes a photo-detector, and the TIA is formed by a first TIA inverter and a second TIA inverter. The first TIA inverter has an input from a cathode side of the photo-detector and the second inverter has an input from an anode side of the photo-detector. A replica TIA is formed by two replica inverters, coupled to a respective input to a first operational amplifier and a second operational amplifier. The first operational amplifier and the second operational amplifier have a feedback configuration for respectively regulating a set voltage level at the cathode side of the photo-detector input of the first inverter and at the anode side of the photo-detector input of the second inverter.

Photoconductive semiconductor amplifier and switch

A switch comprises two photoconductive semiconductors and two corresponding laser diodes driven by opposing voltage sources. The two photoconductive semiconductors are connected in series between a high and low voltage source with a radio frequency output at a center node between the photoconductive semiconductors. Each photoconductive semiconductor may include one ohmic contact and one schottky contact for superior bandwidth and efficiency.