Substitution principles and methods of rectifier diode

Rectifier circuit fault and detection diode can be used a set of methods? How to troubleshoot and repair the fault of rectifier circuit? Rectifier circuit mainly uses rectifier diode, so the fault mechanism of rectifier circuit is related to rectifier diode, and a set of methods of detection diode can be used for troubleshooting of rectifier circuit.

There are two fundamental reasons for the failure of the rectifier circuit: one is the destructive effect of the external circuit on the rectifier diode, which is not the fault of the rectifier circuit itself; The second is the quality problem of the rectifier diode itself, because the working current of the rectifier diode is relatively large, it is easy to fail. The rectifier diode has two hard faults, open circuit and breakdown, and its soft fault is the increase of the forward resistance of the diode and the decrease of the reverse resistance, and the poor working stability. When the forward resistance of the rectifier diode increases, the voltage drop of the rectifier diode at both ends increases, and the DC voltage added to the load resistance of the rectifier circuit decreases, reducing the DC output voltage of the power supply circuit. The larger the rectifier DC working current, the greater the voltage drop of the diodee on the rectifier diode, and the rectifier diode itself is also hot, and the rectifier diode will be burned out in serious cases. After the rectifier diode reverse resistance is reduced, the unidirectional conductivity of the diode becomes worse, so that a part of the AC voltage in the other half cycle is added to the load resistance of the rectifier circuit through the rectifier diode, because this is the AC voltage, so the ripple voltage in the DC working voltage is increased, thereby increasing the burden of the filter circuit.