Improvements in audiometers
Реферат: 765,191. Audiometers. PATENT MAN. AGEMENT, Inc. Jan. 31, 1955 [March 8 1954], No. 2861/55. Class 81(2) An audiometer includes an oscillator capable of producing predetermined frequencies under the control of a first section of a frequency selector switch, the oscillator having a tapped output winding having its tappings connected to stationary contacts of a second section of the switch in such a way that as the switch is operated to adjust output frequency and also to connect a transducer through an attenuator to an appropriate one of the stationary contacts, the transducer is supplied at each selected frequency with a voltage corresponding to the desired acoustic output. The frequency produced by an oscillator including a pentode 10, a feedback winding 33 and a tuning winding 37 is controlled by parts 31, 39, 44 of a first section of a frequency selector switch, which parts contact appropriate stationary contacts connected with tappings of the feed back winding 33, tuning winding 37 and condensers 40, 41, 42 to form various tuned circuits. The inductance of the tuning winding 37 is varied by the provision of a coil 43 energized under the control of another part 48 of the first section of the frequency selector switch. The oscillator output winding 45 is provided with tappings 46 connected with groups of stationary contacts, each group being associated with a part 62, 63 or 64 of a second section of the frequency selection switch. A selector switch 61 is provided to connect either one of two airconducting receivers 51, 52 or a bone-conducting receiver 53 with an attenuator 54. When an air-conducting receiver 51 or 52 is selected for use, a part 57 of a third section of the frequency selector switch is connected by the selector switch 61 with a corresponding part 62 or 63 of the second section of the frequency selector switch so that according to the frequency used, the appropriate output voltage is applied to the receiver by way of the attenuator 54, the resulting audio-output being the same for all frequencies. Similarly when the bone-conducting receiver 53 is selected for use, another part 58 of the third section of the frequency selector switch connects a corresponding part 64 of the second section of the frequency selector switch to the bone-conducting receiver 53 by way of the attenuator 54 so that an appropriate output voltage is supplied. The tappings 46 of the output windings 45 are so connected to the groups of stationary contacts associated with the second section of the frequency selector switch according to the frequency characteristics of the receivers so that for all frequencies the same audiooutput is produced by each receiver. Specifications 638,649, 725,329 and 764,614 [both in Group XXXV] are referred to.
Improvement in cognitive function with fenfluramine
Номер патента: AU2018341331B2. Автор: Brooks M. Boyd,Glenn Morrison,Arnold Gammaitoni. Владелец: Zogenix International Ltd. Дата публикации: 2024-09-26.