| 摘要 |
1,009,064. Automatic volume control. TELEFUNKEN PATENTVERWERTUNGSGESELLSCHAFT, July 24, 1962 [July 29, 1961], No. 28401/62. Heading H4R. In a pilot-controlled automatic volume control system, particularly for multi-channel carrier systems, in which the amplified and rectified pilot is detected by a voltage discriminator which responds to over-level and underlevel and determines the stepping direction of a gain adjusting device 13 controlled by stepping pulses from a pulse generator 11, the voltage discriminator consists of two Schmitt triggers 7, 8 responding to over-level and underlevel respectively, and in so doing controlling a switching device 10 which passes the stepping pulses to the gain-adjusting device 13. The device 13 may change the current flow to an indirectly heated thermistor 14 or may control a motor-driven potentiometer in order to control the gain of the amplifier. Specification 992,663 is referred to. |
