Explore the key factors to reduce LED life loss

In the entire LED industry chain, from the chip to the packaging, the finished product, all the photoelectric indicators of the product need to be tested. Most LED manufacturers will find that after testing, the life of LED products will be affected, and some will be directly scrapped during the test. Why is this? When using a small current for LED testing , the smaller the current, the longer the waiting LED is lit and the test efficiency is very low. Why is this? Most domestic manufacturers believe that this is determined by the characteristics of the LED product itself. It can be changed by non-human resources, but it is not. At present, in the relatively developed LED industry in Europe, America, Japan, Taiwan, etc., major LED manufacturers have begun to use LED test dedicated power supply to deal with this problem. ITECH also offers the IT6200 dual-range programmable DC power supply series, which is tested with an LED test system to reduce the lifetime loss of LED products during testing, while improving test efficiency and maximizing throughput.

LEDLightbar test

In order for the LED to illuminate, it must be energized. Therefore, in the photoelectric performance test of LED products, the usual practice is to use DC power to supply power to the LED products, and to test and record various parameters when the LEDs are lit. In the past, people thought that DC power can be used as long as it can supply power. Therefore, in order to save equipment costs, a general power supply is used for testing. In general LED products, the current allowed to pass is generally less than 30mA, which is impossible for any ordinary power supply, because at the moment of starting, it will inevitably generate huge surge current, which greatly exceeds the LED. The range of currents that can be withstood. Most of the time, due to the short time of this surge current, it will not burn the LED immediately, but it will definitely cause irreparable damage to its life. As a result, the quality and reputation of the products are very unfavorable, which will cause huge economic losses.

The advantage of the Idx IT6200 series DC power supply is that when the LED product test is required, turning on the unique LED mode of the power supply can effectively suppress the surge current at the startup instant, thereby protecting the LED to be tested. If you test with the Itech IT6200 series DC power supply, the life of the LED product will not be affected.

Now let's do an experiment and test the 170 light LEDlightbar with the IT6200 series DC power supply. Connect the LEDlightbar to the IT6200 series DC power supply, select LEDmode in the menu; then set the current command to Iset=10mA; activate the power on button to start powering the lightbar. The oscilloscope shows the current change of the IT6200 series power supply as shown below:

Figure 2: Oscilloscope shows current changes in the IT6200 series power supply

As can be seen from the figure, when the LEDmode is selected for testing, the current of the IT6200 DC power supply series rises very smoothly to the set value at startup, and there is no surge current generated, so it will not affect the life of the LED product. .

If you don't use LEDmode for the same test, what happens? You can turn off the LED mode of the IT6200 series power supply to do the same test. At this point, the current recorded by the oscilloscope changes as shown below:

Figure 3: Current changes recorded by the oscilloscope