| 摘要 |
The circuit generates an AGC voltage. It has a circuit generating a composite video signal including a synchronisation signal, and a source generating periodic pulses normally coinciding with the synchronisation pulses. The AGC voltage generator has a filter capacitor. A signal converter (20) has a first signal path (350, 30, 360) which responds to the periodic pulses and the composite video signal and charges the filter capacitor. It has a second path (372, 380) which responds to the same signals and discharges the filter capacitor whose net charge generates the AGC voltage related to the level of the synchronisation signal in the video signal.
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