I am using a Meanwell LDD 350ma driver with a 12v power supply.

Datasheet has note that output voltage will always step down 3 volts from input. If I understand it correctly that means that output will be 9v in my case.

What happens when I connect led array which requires 13.6v at 350ma?

Will it work and if it does is there any problem with this? Less brightness is not problem, could it damage diodes or driver.

  • \$\begingroup\$ Expect flames . \$\endgroup\$ Sep 28 '16 at 1:25
  • \$\begingroup\$ Probably won't work. It doesn't sound like you have a good handle on what you're doing. You should do more research into driving LEDs, what it is that you have, and what you need to drive them. \$\endgroup\$
    – Daniel
    Sep 28 '16 at 1:39

You are misinterpreting the datasheet- it means that the input voltage must be at least 3V higher than the output voltage to guarantee current regulation. The output voltage will actually vary with LED voltage to maintain a regulated output current when it is in regulation. I can see how you might take it literally.

With a significantly insufficient input voltage you will get insufficient output current, maybe not enough to get much light.

So either give it more input voltage, a more appropriate LED array, or a different LED driver.

  • \$\begingroup\$ I have star with 3 LED which requires 8.6V. Even with 9V input it is working but it is less bright than with 12V. \$\endgroup\$ Sep 28 '16 at 2:28
  • \$\begingroup\$ Can you confirm that using it with insufficient input voltage will destroy driver and LED? \$\endgroup\$ Sep 28 '16 at 2:37
  • \$\begingroup\$ It shouldn't do any such thing. \$\endgroup\$ Sep 28 '16 at 3:06

Use a laptop charger or any PS that meets the your requirements.

  • 13.6+3 = 16.6 V min at 0.4A min = 8 watts min.
  • Observe ESD precautions and avoid reverse voltages.

Use twisted pair and keep wires short to avoid 100KHz PWM noise problems.


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