Check like a normal diode. In case of doubt, replace it with a new one, sometimes the measurement will show that the diode is ok, but in fact it was dead. Regards
A colleague is right, the zener diode cannot be checked with a meter 100%, because the zener effect is used - it conducts at a certain voltage, but normally, if it is good, it behaves like a normal diode. Regards.
You can check like this. Connect the diode in series with the resistor. Apply a voltage higher than the expected zener voltage. For a given zener and supply voltage, the resistor must be selected so that the current Iz flows (from the catalog). Now it is enough to measure the voltage across the zener diode. If at the current Iz (e.g. 5mA - for 0.5W diodes) we measure more or less the catalog Vz, then the diode is good.
For this I use a laboratory power supply with adjustable voltage and current limitation. I connect the diode to the flowing current, set the limiter to the minimum and slowly increase the voltage. At some point, the voltage stops rising, it is the zenner breakdown voltage.
Please suggest me too. The diode is located in the audio amplifier circuit to which the power supply is NOT connected. I set the diode test in the multimeter. I put the probe in one direction, it shows me about 0.5V and in the other direction the multimeter indication increases gradually to about 2.2V. What does it mean? How do I interpret it?
Hello, the diode is soldered into the circuit so you measure the influence of adjacent elements. One tip should be desoldered for a reliable measurement. Maybe show the diagram. Regards
Hello, without desoldering, you have the influence of the surrounding elements, you mentioned a slow increase in voltage - you probably have an electrolytic capacitor nearby. The measurements show that the element behaves as a diode but does not say anything about the zener effect, this cannot be measured directly with a multimeter. Regards
To test a Zener diode using a digital multimeter, it is recommended to first check it like a normal diode. However, due to the Zener effect, a multimeter may not provide a definitive test. A reliable method involves connecting the Zener diode in series with a resistor and applying a voltage higher than the expected Zener voltage, ensuring the current matches the specifications from the catalog. The voltage across the Zener should then be measured; if it aligns with the catalog value at the specified current, the diode is functioning correctly. For more accurate results, especially when the diode is part of a circuit, it is advisable to desolder one end to avoid interference from adjacent components. Observations of voltage readings can indicate the diode's condition, but the Zener breakdown voltage can only be accurately determined with a controlled power supply setup. Summary generated by the language model.
