1. Identification of zener diodes in the circuit: zener diodes are commonly used in circuits with “ZD” plus digital representation, such as: ZD1 denotes a regulator with a number of 1.
2. Identification of zener diodes _ positive and negative electrode identification From the appearance point of view, the positive terminal of the metal package zener diode body has a planar shape, and the negative electrode end has a semicircular surface shape. One end of the plastic zener diode printed with a colored mark is a negative electrode, and the other end is a positive electrode. For undetermined zener diodes, the multimeter can also be used to determine its polarity. The measurement method is the same as that of ordinary diodes. That is, use a multimeter R×1k file to connect the two table pens to the two electrodes of the zener diode. After the results, the two pens were measured again. In the two measurement results, when the resistance is small, the black pen is connected to the anode of the zener diode, and the red pen is connected to the cathode of the zener diode.
3. The identification of zener diode _ color ring zener diode identification color ring zener diode Domestic products are rare, most of them from abroad, especially in Japan. General color ring voltage regulator diodes are marked with models and parameters, detailed information can be found in the component manual. The color ring zener diode is small, power is small, voltage regulation value is mostly within 10V, it is easy to breakdown damage. The appearance of the color ring zener diode is very similar to the color ring resistance, so it is easy to mistake. The color ring on the color ring zener diode represents two meanings: one is the number, and the second is the number of decimal places (usually the color ring voltage regulator diode is a decimal point, expressed in brown. It can also be understood as the magnification: ×10 (-1th power), the specific color corresponds to the same color ring resistance).
4. The identification of zener diodes - The difference between zener diodes and ordinary rectifier diodes.
First use the multimeter R×1K block to judge the positive and negative electrodes of the tube under test. Then put the multimeter to R×10K block, the black pen is connected to the negative pole of the tested tube, and the red pen is connected to the positive pole of the tested tube. If the measured reverse resistance value is greater than the reverse resistance measured with R×1K block, A lot less, indicating that the tube under test is a voltage regulator; conversely, if the measured reverse resistance is still very large, it means that the tube is a Rectifier Diode or a detection diode. The reason for this identification method is that the internal battery voltage of the multimeter R×1K block is 1.5V, and generally the reverse breakdown of the tested pipe will not occur, so that the measured resistance value is relatively large. When R×10K block is measured, the voltage of the internal battery of the multimeter is generally above 9V. When the tested pipe is a voltage regulator, the value of the cut-off voltage is lower than the battery voltage, it is reversed and the measured value is measured. The resistance value is greatly reduced. However, if the tube under test is a general rectification or detection diode, whether or not it is measured with R×1K or R×10K, the resulting resistance will not be very different. Note that when the voltage regulation value of the zener diode under test is higher than the voltage value of the R×10K block of the multimeter, it is impossible to distinguish between them by this method.
