How to measure the leakage of voltage regulator diodes

How to measure the leakage of voltage regulator diodes

The voltage regulator diode is usually used to measure leakage on an oscilloscope. Gradually apply reverse voltage at both ends of the voltage regulator diode, and when the critical point is reached, the leakage current of the voltage regulator diode gradually increases. The higher the voltage, the greater the leakage current. Using a multimeter to measure the forward and reverse resistance of a voltage regulator diode can only roughly determine its quality.

We all know that the voltage regulator diode operates in a breakdown state, so this characteristic can be used to distinguish whether it is a regular diode or a voltage regulator tube. Using a 500V megger, connect the output end of the megger to a multimeter in parallel, either a digital meter or a pointer meter. Adjust the voltage range of the multimeter to 500V, shake the megger to make the needle deflect in the positive direction, and the red lead is the positive electrode.

Overlap the two probes on the two electrodes of the tested tube. If the positive and negative electrodes of the tested tube are known beforehand, connect the red probe to the negative electrode of the tested tube and shake the meter. The voltage value measured on the meter is the stabilized voltage value of the stabilized voltage tube. If the positive and negative electrodes of the tested tube are not known, shake and check the voltage first. If there is no voltage (0.5 volts), switch the probe before measuring. This method is suitable for detecting voltage regulators below 200V. If the measured voltage exceeds 200V, the possibility of a diode is high. However, it should be ruled out that this transistor is a low back voltage diode.