Simple test method of Zener diode: This kind of method only needs a digital multimeter. The method is: put the digital multimeter in Rx15k block and adjust the zero accurately. The red DC ammeter is connected to the positive stage of the tested zener tube, and the black DC ammeter is connected to the negative stage of the tested tube. When the needle is moved to a certain position, read its stable data information from the 10V DC working voltage scale of the digital multimeter, and then Use the following formula to calculate the voltage regulator tube value: the measured voltage regulator tube value (V) = (10V-reading standard value) x 1.5. With this method, the Zener diode whose value is below 15V can be measured.
The test method of the external power supply of the Zener diode: Use a 0V~3V adjustable regulated power supply and a 1.5KΩ resistor to connect according to the following diagram. For accurate measurement, first adjust the output voltage of the adjustable stabilized power supply to 19V, and use the digital multimeter to measure the two DC voltage values immediately and accurately. The reading is the value of the Zener diode regulator tube. If the measured standard value is 15V, it is very likely that the diode has not penetrated in the reverse direction. At this time, the output voltage of the adjustable regulated power supply can be adjusted to 20V or above, and then accurately measured according to the described method.
The appearance design of common Zener diode is similar to the appearance design basis of general small output power rectifier diode. When the model specification mark on the cover is clear, it can be distinguished in many ways according to the model specification. When the model specification is marked down, the resistance bar of the digital multimeter can be used to accurately distinguish the Zener diode from the general rectifier diode. First distinguish the positive and negative electrodes of the tube under test. Then turn the digital multimeter to the Rx15k block, connect the black DC ammeter to the negative stage of the tube under test, and connect the red DC ammeter to the positive stage of the tube under test. If the measured resistance in the opposite direction is compared with the reverse of the precise measurement with the Rx1k block The directional resistance is much smaller, indicating that the tube under test is a Zener diode; on the contrary, if the measured resistance in the opposite direction is still very large, it indicates that the tube is a rectifier diode or a detection diode.
The basic principle of this type of identification method is that the internal battery voltage of the digital multimeter Rx1k block is 1.9V, and it is generally not easy to penetrate the tube under test in the reverse direction, so the measured resistance in the reverse direction is relatively large. When the Rx15k gear is used for accurate measurement, the working voltage of the internal rechargeable battery of the digital multimeter is generally above 9V. When the tested tube is a Zener diode and the value of the Zener tube is less than the battery voltage value, it will be penetrated in the opposite direction. The measured resistance is greatly reduced. But if the tube under test is a general rectifier or detector diode, no matter if the Rx1k block is used for accurate measurement or the Rx15k block is used for accurate measurement, the personal resistance value will not easily be very different. Note that when the voltage regulator tube value of the tested Zener diode is higher than the working voltage value of the Rx15k block of the digital multimeter, it is impossible to distinguish it in this way.
The above explained is the measurement method of the voltage stabilizer value of the Zener diode. I hope it will be helpful to you after reading it. If you want to know more about the Zener diode related information, please contact customer service online or call our company Service hotline (upper right corner of the website) for consultation, we will wholeheartedly provide you with quality service!