Auxiliary video gain control apparatus e.g. for a television receiver.

摘要

In a television receiver, an output signal from a binary rate multiplier (BRM) (24) is used to control the amplitude of a video signal and thereby the contrast of a displayed image. Contrast control in response to ambient lighting conditions is accomplished by means of a light dependent resistor (52) which modifies the output pull-up voltage of the BRM (24) at an output node (A).