Remote cable control for colour saturation of TV receiver - has two potentiometers linked by resistor shunted by diode which is poled to allow back and white operation

摘要

The remote colour saturation cable control for a colour television receiver has a potentiometer setting a DC voltage used to a colour signal amplifier. The slider (10) of a second potentiometer (9) in the remote control unit (8) is connected to a dividing point (14) on the first potentiometer (4) via a resistor (11) shunted by a diode (12). The resistor value is chosen so that the current passing into the first potentiometer at most causes an increase in colour saturation of the required maximum (20%). The diode is poled so that it conducts down to the lowest colour saturation level, thus allowing black and white operation.