Inspection methods and alternatives for damaged rectifier diodes

First, remove all the rectifier diodes in the rectifier, and use the 100×R or 1000×R ohm gear of the multimeter to measure the two lead wires of the rectifier diode (the head and the tail are reversed once for each measurement). If the resistance values measured twice are very different, for example, the large resistance value is as high as several hundreds of KΩ to infinity, while the small resistance value is only a few hundred Ω or even smaller, indicating that the diode is good (soft breakdown has occurred). except diodes). If the resistance values measured twice are almost equal, and the resistance value is small, it means that the diode has been damaged by breakdown and cannot be used. If the resistance value of the two measurements is infinite, it means that the diode has been disconnected internally and cannot be used.

After the rectifier diode is damaged, it can be replaced with a rectifier diode of the same type or another type of rectifier diode with the same parameters.

Generally, rectifier diodes with high withstand voltage (reverse voltage) can replace rectifier diodes with low withstand voltage, while rectifier diodes with low withstand voltage cannot replace rectifier diodes with high withstand voltage. A diode with a high rectified current value can replace a diode with a low rectified current value, while a diode with a low rectified current value cannot replace a diode with a high rectified current value.