A simple testing method for led Lamp
1. Observe the appearance of the lamp bead and distinguish the anode and cathode of the lamp bead. A simple method for detection of led. Turn the multimeter gear and select the transistor file. During the test, a set of data is displayed on the multimeter, showing the bias of the diode PN junction. Of course, when measuring LED, you don’t need to look at any data.
2, use flashlight detection: connect the LED lamp to a flashlight, and then turn on the flashlight, if the LED lamp works normally, it means that the LED lamp is normal, otherwise it may be damaged or poorly wired.
3. The detection of LED lamp string is also relatively simple, which can be measured with the resistance file of the multimeter or the diode file. The diode gear of the digital meter can even make the normal LED glow slightly, directly observing whether it is normal or not. Confirm to the bad LED lamp beads and replace them with good ones.
How to measure led driver with multimeter, how to measure LED driver chip with multimeter? _ Baidu.
The voltage of non-isolated LED power supply under no-load condition is about 300V tested by multimeter and about 220V with current-by-current PFC. The isolated LED power supply, the voltage in the no-load state is tested with a multimeter, and the total voltage is about 3-5V more than the rated number of LED series.
It is impossible to measure the quality of LED with ordinary pointer multimeter, because the working voltage of LED is about 7V, while the internal voltage of ordinary pointer multimeter is only 5V, so when measuring LED with the resistance file of ordinary multimeter, its forward and reverse resistance is infinite.
I don’t know if you are talking about LED display unit board or full-color LED driver chip. Generally, you can compare the voltage of the same pin of the normal driver chip, the resistance parameters, and the on-off test to see if the short circuit, short circuit. The most important thing is to be familiar with the function and routing mode of each driver chip on the unit board.
The multimeter can not be measured, so we can only simply test whether the input and output are short-circuited. If it is the simplest resistance-capacitance constant current source, you can test whether the capacitor is short-circuited, as long as the capacitor is not short-circuited, connected to the led lamp string, the power will be on.
Tools: multimeter, LED light turns the knob on the multimeter to the diode (buzzing) file, and inserts the red and black meter pen in the correct position of the multimeter. Observation lamp, there are four-legged and two-legged, if the measurement is four-legged, the middle two feet are selected.
The LED power supply is usually DC, your father’s multimeter turns on the DC DC file, and then the two pens touch the two polar terminals of the LED power supply respectively. If a voltage is displayed on the multimeter, it is good.
How to measure the quality of LED lamp by multimeter
1. The red pen of the multimeter is in contact with the anode contact body of the lamp, and the black pen of the multimeter is in contact with the cathode contact body. See if the lights are on. If the light is on, it means that the function of the lamp bead is basically all right. If the lamp is not lit, swap the red and black watch pen and test it again. Lest the cathode and anode of some lamp beads are opposite to the general ones.
2, the multimeter measures the quality of LED lamp beads in the following ways: 1, the multimeter chooses the diode file, the red meter pen connects the lamp bead anode, the black meter pen connects the lamp bead cathode, if the lamp bead is slightly bright, it is good, otherwise it is bad. 2, the multimeter selects * 10k resistance file, the red meter pen connects with the lamp bead anode, the black meter pen connects with the cathode, the lamp bead is slightly bright is good.
3. A, use a universal red pen to connect the positive contact of the LED lamp bead, and use a universal meter black pen to connect the negative contact. When the LED lamp bead has a small brightness, it is good, otherwise it may be bad.
4, you can also use the diode file of the digital multimeter to measure the quality of the LED, the red meter is connected with the positive pole of LED, and the black meter is connected with the negative pole of LED. At this time, the digital multimeter displays around 1700, and the reverse measurement will be infinity. It shows that “1Muffle, which can basically prove that LED is good.”
How to use the multimeter to test the LeD driver?
Measure the driver with a multimeterOutput voltage ofIf the value of the test is the same as that marked on itIndicating that the drive is good Otherwise, the drive is broken.Yes. The performance of a broken led drive.
Unisolated LED power supplyThe voltage under no-load condition is about 300V measured with a multimeter and about 220V with current-by-current PFC. The isolated LED power supply, the voltage in the no-load state is tested with a multimeter, and the total voltage is about 3-5V more than the rated number of LED series.
Observe the appearance of the lamp bead and distinguish the anode and cathode of the lamp bead. A simple method for detection of led. Turn the multimeter gear and select the transistor file. During the test, a set of data is displayed on the multimeter, showing the bias of the diode PN junction. Of course, when measuring LED, you don’t need to look at any data.
Pointer multimeter to 10K resistance file test, digital multimeter to diode file test, it is good to see that the light can be slightly lit. When measuring, the influence of the internal resistance of the multimeter should be taken into account.