AUTOMATIC CHROMINANCE CONTROL AND COLOR KILLER CIRCUITS

摘要

An automatic chrominance control and color killer circuit for use in a color television receiver having a gain controllable chrominance amplifier for selectively amplifying chrominance signals and a color burst signal transmitted with a composite television signal during a color television transmission. The circuit further has a burst level detector connected to the chrominance amplifier , a control circuit including a time constant circuit connected to the burst level detector for deriving a control signal, which is supplied to the chrominance amplifier for controlling the gain thereof in response to the level of the control signal during the presence of the burst signal and for activating and inactivating the chrominance amplifier when the level of the control signal goes over and below a predetermined level, and a circuit connected between the burst level detector and the time constant circuit for shortening the time constant of the latter when the level of an output signal of the former goes below a predetermined level.