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彩色电视机的开关电源、行场扫描电路中所用的二极管要求较高,如有损坏,决不能随便代换,否则就有可能导致新器件再次损坏,甚至造成故障的进一步扩大。本文介绍这部分电路中所用二极管的选择代换方法,供初学者参考。 1.串联及开关型稳压电源中整流二极管的选择 串联型稳压电源不存在开关干扰问题,故它所用的整流二极管就是普通整流二极管。但是,开关型稳压电源如果使用普通整流二极管,则会因普通整流二极管反向恢复时间太长,而造成开关干扰。因此,开关型稳压电源中的整流管,要选用快恢复型整流二极管。不过,从电网直接整流的二极管也可用普通整流二极管。而负载端(即开关电源输出端)的整流二极管,则必须要用快恢复整流二极管。 整流二极管的选择代换,一般只要考虑最高反向工作电压(峰值)Vmax和额定正向整流电流(平均值)I_D这两个
Color TV switching power supply, field scan circuit used in the diode higher, if damaged, must not be replaced, otherwise it may cause the new device again damaged, or even cause further expansion of the fault. This article describes the selection of diodes used in this part of the circuit substitution method for beginners. 1. Series and switching power supply rectifier diode in the choice of series-type power supply switching interference does not exist, so it is used in the rectifier diode is a common rectifier diode. However, the switching regulator power supply if the use of ordinary rectifier diodes, it will be due to the ordinary rectifier diode reverse recovery time is too long, resulting in switching interference. Therefore, the switching regulator power supply rectifier, to choose fast recovery type rectifier diode. However, diodes that are directly rectified from the grid are also available as normal rectifier diodes. The load side (ie switching power supply output) of the rectifier diode, you must use the fast recovery rectifier diode. Rectifier diode replacement, generally only consider the maximum reverse voltage (peak) Vmax and rated forward rectifier current (average) I_D these two