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彩电中设有消磁电路,接于50Hz、220伏的交流电路中。它是利用交流电通过消磁电阻(PTC)作为控制元件,在与之串联的消磁线圈中产生一逐步衰减的50Hz交变磁场,消除显象管内金属部件的剩余磁化量,使电子束准确运动,保证色纯。 消磁电阻是一正温度系数的热敏电阻,具有常温下阻值低、加压后有很大的起始电流,并阻值随温度上升而急剧增大的特性。消磁电路在通电瞬间,起始大电流(彩电一般在3安以上)流过热敏电阻使之发热而电阻剧增,之后,消磁回路电流快速衰减(约3—4秒)至几十毫安乃至几毫安而趋于稳定,达到消磁的目的。
There is a degaussing circuit in the TV, connected to 50Hz, 220V AC circuit. It is the use of alternating current through the degaussing resistor (PTC) as a control element, in the degaussing coil connected in series to produce a gradually attenuated 50Hz alternating magnetic field to eliminate residual magnetization of metal components within the imaging tube, the electron beam accurate movement, to ensure Pure color. Degaussing resistance is a positive temperature coefficient of the thermistor, with a low temperature at room temperature, a large initial current after the pressure, and the resistance increases sharply with the temperature rise characteristics. Demagnetizing circuit in the moment, the initial high current (color TV generally above 3 amps) through the thermistor to heat and the resistance surge, after degaussing circuit current decay rapidly (about 3-4 seconds) to dozens of milliamperes Even a few milliliters and tends to be stable, to achieve the purpose of degaussing.