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由中放电路输出的全电视信号经过4.43 MHz带通滤波器,进入色带通放大器,在色同步选通脉冲的控制下分离出色度信号和色同步信号。色度信号经过色饱和度控制电路后,送入主延时解调器,解调出FU和FV信号。色同步信号分成三路:一路送至ACC(自动色度控制)电路,产生ACC电压去控制从色带通放大器输出的色度信号的幅度;第二路送至消色电路,当没有或只有很微弱的色同步信号,并且没有副载波信号或相位不正确时产生消色电压,通过色饱和度控制电路关闭色度信号通道,使彩色电视机只显示黑白图像;第三路送至APC(自动相位控制)电路,用以控制副载波恢
The full TV signal output by the intermediate circuit passes through a 4.43 MHz band-pass filter and enters the bandpass amplifier to separate the chrominance signal and the color burst signal under the control of a burst gate. Chroma signal through the saturation control circuit, sent to the main delay demodulator, demodulation of the FU and FV signals. The color burst signal is divided into three channels: all the way to the ACC (automatic chrominance control) circuit to generate ACC voltage to control the amplitude of the chrominance signal output from the bandpass amplifier; the second channel to the achromatic circuit, when no or only A very weak color burst signal and no achromatic signal when there is no subcarrier signal or the phase is incorrect; the color signal channel is closed by the color saturation control circuit to make the color television display only the black-and-white image; the third is sent to the APC ( Automatic phase control) circuit to control subcarrier recovery