Zener diode is one of the common components in electronic circuits, especially power supply circuits. Different from ordinary diodes, it often works in the reverse breakdown area of PN junction. As long as its power consumption does not exceed the maximum rated value, it will not be damaged.
1. Identification of Zener diode.
Common zener diodes have two pins, but a few zener diodes have three pins (such as 2dw7). In addition to being identified by the mark of the shell, beginners should learn to use a multimeter to distinguish zener diodes from ordinary diodes.
2. Detection of Zener diode.
Measure the forward and reverse resistance with the r-1k gear of the multimeter. The reverse resistance value is large under normal conditions. If the meter needle swings or other abnormal phenomena are found, it indicates that the regulator tube has poor performance or even damage. The method of energizing the circuit can also roughly measure the quality of the voltage stabilizing tube. The method is to use the DC voltage gear of the multimeter to measure the DC voltage at both ends of the voltage stabilizing tube. If it is close to the voltage stabilizing value of the voltage stabilizing tube, it indicates that the voltage stabilizing diode is basically intact; If the voltage deviates too much from the nominal voltage stabilizing value or is unstable, the voltage stabilizing tube is damaged.