Led driver blowing led string

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#1

Hello

I am using the AK led driver powered at 28v supplying 2x3w LEDs in series. The device is configured for 500ma and the leds are 700ma. Turning off and powering up the 28vdc input caused the led string to fail. I have seen this behavior with other drivers and picked yours because of the soft start feature. What can I do to prevent the led damage on power cycles ?

Thanks

Tom

#2

Hello @N20087 ,

What does it mean “caused the LED string to fail”? Are they broken (definitively) or just they fail to turn on the first time (or a second time)?

Soft-start requires an external capacitor:

image
image1396×217 30.7 KB

Vset is the CTRL pin of the AK-LED-DRIVER board.

#3

Burned out…open circuit after maybe 4 or 5 power cycles

#4

Can you share the LEDs part number and datasheet?