| 摘要 |
1,163,293. Automatic voltage control. AUTOMATIC TIMING & CONTROLS Inc. Sept. 29, 1966 [Jan. 7, 1966], No. 43601 / 66. Heading G3R. An oscillator with a regulated output comprises: - input terminals 93, 95; an output terminal 94; output transistors 77, 83 associated with an oscillation -sustaining positive feedback network including a Wien bridge 65, 91, 63, 85; a circuit including a terminal 5 connected to a reference voltage source, transistors 7, 8, 9 and 21, capacitors 13, 17 and resistors 15, 19 for producing an error signal in dependence upon variations in the amplitude of the oscillator output; and a D. C. negative feedback circuit including a potentiometer 53, a resistor 49, and an optional temperaturecompensating thermistor 47, this circuit being connected to the base of a transistor 43, which base also receives an A. C. negative feedback signal by way of a resistor 41 and capacitor 39 to the emitter of which is applied the said error signal. The arrangement is such that the unijunction transistor 35 acts as a variable impedance, controlled by the magnitude of the error signal, in the negative feedback circuit so that the amplitude of the A. C. negative feedback signal applied to the input of the oscillator is correctively varied in a sense to maintain constant the amplitude of the oscillator output, the modified signal from uni-junction transistor 35 being applied to the output transistors 77 and 83 by way of the transistor 43 and further transistors 59, 69 and 87. The D. C. feedback signal serves to stabilize the mean D. C. level of the A. C. output. |
