Zener diode is one of the common components in electronic circuits, especially power circuits. Unlike ordinary diodes, it usually works in the reverse breakdown zone of the PN junction, and as long as its power consumption does not exceed the maximum rating, it will not be damaged. Let us understand the identification and detection methods of Zener diodes below:
The identification method of the positive and negative poles of the Zener diode: The identification method of the positive and negative poles of the Zener diode is the same as that of the ordinary diode, and the different characteristics of the positive and negative resistance of the PN junction can be used to identify. In practice, the R×1k file of an analog multimeter is often used to measure the resistance value between two pins, and the red and black probes are exchanged before the measurement. The smaller of the two resistance measurements, the pin connected to the black test lead is the anode of the Zener diode, and the pin connected to the red test lead is the cathode. The three-pin Zener tube looks like a triode from the outside, but the inside is connected to two A positive Zener diode. The method for identifying the positive and negative electrodes of the Zener diode is the same as the Zener with two pins, only the common anode (ie the first pin) needs to be detected, and the remaining two pins are all negative electrodes.
Zener diode is tested by measuring its positive and negative resistance with a multimeter R×1k. Generally, the resistance of a negative resistance is relatively large. If the instrument pin swings or other abnormal phenomena are found, it indicates that the performance of the Zener diode is poor or even damaged. The quality of the Zener diode can also be measured simply by energizing the circuit. The method is to measure the DC voltage at both ends of the Zener tube with the DC voltage file of a multimeter. If the stabilized voltage value of the Zener diode is close to the stabilized value, it indicates that the Zener diode is intact. If the voltage deviates too much from the nominal regulation value or is unstable, it means that the Zener diode is damaged.