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笔者在检修一些夏普彩电时,往往发现一种外形与普通二极管相似的二极管,用万用表R×1k档测量,正向电阻高达50～500kΩ。这种二极管与普通二极管有较大的区别,它是一种变阻硅晶体二极管,或称压敏二极管。在夏普彩电中,该二极管主要作用是过压保护和限幅。若其阻值变化或损坏,将会使电视机工作失常,甚至损坏电源部分的元器件。例如夏普C1803CK/DK型彩电的开关电源电路中D711就是一只变阻二极管,型
In the repair of some Sharp color TV, I often find a diode similar to the shape of a diode, measured with a multimeter R × 1k file, the forward resistance of up to 50 ~ 500kΩ. This diode and the general diode has a greater difference, it is a resistance of silicon crystal diodes, or pressure-sensitive diodes. In Sharp TV, the main role of the diode is over-voltage protection and limiting. If the resistance changes or damage, will make the TV work abnormal, or even damage the power supply components. For example, Sharp C1803CK / DK-type color TV switching power supply circuit D711 is a variable resistance diode, type