Color temperature control circuit

A color temperature control circuit for use in a color television receiver for changing the ratio of blue, red and green chrominance signals obtained from a chrominance signal demodulator in relation to a luminance signal obtained from a video amplifier, said color temperature control circuit comprising:

• a reference voltage generator for generating a predetermined reference voltage;
• a first differential amplifier connected to said chrominance signal demodulator for defining a first current path for said green chrominance signal to ground, said first differential amplifier also connected to said reference voltage generator and said video amplifier for comparing said luminance signal with said reference voltage such that when said luminance signal drops below said reference voltage, said first current path actuates to conduct said green chrominance signal to ground with a conductivity determined by the degree of said voltage drop of luminance signal below said reference voltage to reduce the green chrominance signal level;
• and
• a second differential amplifier connected to said chrominance signal demodulator for defining a second current path for said red chrominance signal to ground, said second differential amplifier also connected to said reference voltage generator and said video amplifier for comparing said luminance signal with said reference voltage such that when said luminance signal drops below said reference voltage, said second current path actuates to conduct said red chrominance signal to ground with a conductivity determined by the degree of said voltage drop of luminance signal below said reference voltage to reduce the red chrominance signal level.