彩色电视机在使用过程中常因电源电压波动、机内温度升高等因素,使调谐好的频率发生漂移,造成图象、色彩和伴音不稳定现象。为此,在新型彩电上都加有一个AFC(自动频率)开关。 按下该开关(ON)接通后,电路中的自动频率跟踪系统将频率偏离量变成直流电压,去控制高频头的调谐频率,在一定的偏离范围内,使电视机始终保持在正 Color TV in the course of the power supply voltage fluctuations often occur, the temperature inside the machine and other factors, the tuned good frequency drift, resulting in images, colors and sound instability. To this end, in the new color TV are added an AFC (automatic frequency) switch. Press the switch (ON) is turned on, the automatic frequency tracking system in the circuit into a DC voltage frequency deviation, to control the tuner tuner frequency, within a certain deviation, so that the television is always in positive