CIRCUIT FOR REGULATING THE COLOR SUBCARRIER AMPLITUDE IN A VIDEO RECORDER

摘要

A circuit for regulating the color subcarrier amplitude in a video recorder used with a television receiver which employs overscanning of the electron beams for different modes of operation includes a regulating circuit for providing a regulating voltage representative of the amplitude of the color subcarrier. The regulating circuit includes a variable time constant circuit for switching from a short time constant during the overscanning to a long time constant immediately prior to ending the overscanning to change the regulating voltage in response to changes in the time constant. A variable amplifier is responsive to the regulating voltage to regulate the amplification of the color subcarrier in response to changes in the time constant.