Date:2025-07-30 Categories:Product knowledge Hits:270 From:Guangdong Youfeng Microelectronics Co., Ltd
The positive and negative polarity can also be determined by measuring the forward and reverse resistance values of the light-emitting diode using the R × lOk range of a multimeter. When the pointer of the multimeter deviates significantly in the positive direction, the black probe is connected to the positive terminal.diode
(2) Judgment of performance quality. When measuring the forward and reverse resistance of a light-emitting diode using the R × lOk range of a multimeter, it should have the measurement characteristics of a regular diode. When measuring the forward resistance value, a faint light will be emitted inside the tube.diode
Attention: Do not measure the forward and reverse resistance values of the light-emitting diode using the R × lk range of the multimeter, otherwise it will be found that the forward and reverse resistance values are close to infinity. This is because the forward conduction voltage of the light-emitting diode is greater than 1.8V, which is higher than the voltage value of the 1.5V battery when the multimeter is in the R × lk range and cannot be made conductive. At this point, the performance of the light-emitting diode can be judged by connecting an external battery. Measure the schematic diagram, and if the diode can emit light normally, it indicates that the light-emitting diode is intact.diode
Two multimeters, both placed in the R × 10 range, can be connected in series to test the light-emitting diode. If the diode can emit light normally, it indicates that the light-emitting diode is intact.diode
There is also a color changing light-emitting diode that can emit three colors. It consists of two light-emitting diodes connected by a common cathode, with K being the common cathode (negative electrode), R being the positive electrode of the red light-emitting diode LED1, and G being the positive electrode of the green light-emitting diode LED2. The detection method is the same as that of a regular light-emitting diode.
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