Multimeter to test the quality of LED lamp beads
A pointer type multimeter, rotate to the 10K resistance range, and use the red and black probes to measure the LED beads separately. Cross measure the positive and negative directions. When the parallel group of two beads are fluorescent at the same time, the pointer will move. If the reverse measurement does not light up, the meter pointer will not move, and the positive and negative phases of the LED beads can be determined at once. The red probe is the negative terminal. If you apply DC power to the LED beads, it is exactly opposite to the probe used to measure the 10K range, and the red probe is the positive terminal.
The advantages of using a pointer type multimeter to test LED lights can be achieved by the movement of the pointer, causing the light beads to flash and look directly at it. I think it is not inferior to the efficacy of other meters, and you can also give it a try!
The 10k resistor range uses a battery with a voltage of 9-15V. When a large resistor is connected in series, make sure the pointer returns to zero to measure the resistance above 10k.
Because LED beads only light up with a few milliamps of current, when measuring resistance, the small current creates a circuit for the LED light, which performs work and emits light.
By the way, I would like to share a small production: because the battery equipped with this multimeter is not durable, I found two mobile phone batteries connected in series at 8V. This way, the voltage is not enough and the pointer cannot return to zero. So, I changed the resistor and selected a positive type resistor from a large number of resistors. After changing it, it still works well. After using it for a year, I found that the pointer cannot return to zero at 10k gear, indicating that the battery needs to be charged, which is very convenient and convenient.
A digital multimeter can usually measure the quality of LED light beads quickly. Previously, I sent a method of using a multimeter to measure the quality of LED light beads. The diode mode of the multimeter can be used. Nowadays, almost every type of digital multimeter has this mode, so no matter which type of multimeter is used, it can be measured relatively quickly (only for digital, pointer type).
Series connection method
This detection method is also very simple. First, open the lampshade of the LED light to be tested and expose the LED beads. Generally, the LED beads inside are connected in series, so using a diode gear can supply power to this LED bead. If the polarity is not reversed, the normal LED bead will light up, and the damaged LED bead will definitely not light up. Due to the diode gear we choose, the difference in display content between the bad LED bead and the good LED bead can also be clearly displayed on the screen.
