I want to create a dimmer for high power LED light's i'm building for video work. I'm using CREE CXB3590 chips, which have run at 36V with a forward current of 3.6A. I am powering these through a 150W 12V power adapter, hookued up to a step up converter that has a separate pot for current and voltage regulation. I want to create a dimmer for these lights, and I would like to do it as simply as possible. I have a box of assorted resistors and some 100K pots, so the question is, can I use these resistors and a 100K pot to dim my lights, and if so, how would I go about doing so? I don't know how the math works, but I can follow a schematic so I'd appreciate any help the community could offer. Thank you!

  • \$\begingroup\$ At a minimum you'll need to supply a datasheet link for the power supply. A schematic would be even better. Proof-read your question title too while you're editing! \$\endgroup\$
    – Transistor
    Apr 28, 2018 at 18:42
  • \$\begingroup\$ Welcome to the site. Please realise that this is not a free design house, homework-answering service or an on-line technical encyclopedia, copied out to you on demand. This means we will not provide you with a schematic or do the math for you. People will help you take the next step if your question shows that you've done as much as you possibly could on your own - which your post doesn't, I'm afraid. Again, a warm welcome to the site. \$\endgroup\$
    – Oldfart
    Apr 28, 2018 at 18:44
  • 2
    \$\begingroup\$ Unsolder the current pot from your step up converter, run wires from the PCB to wherever you want the dimmer knob located. Job done. \$\endgroup\$
    – winny
    Apr 28, 2018 at 18:59

1 Answer 1


I'd recommend you 86 the 12V power supply and boost driver.

Use a $40 Mean Well HLG-150H-36 CC Driver. It has a pair of DIM wires where you connect a 100K pot to set the current. I use 10 resistors and a jumper to select the current.

I have to question your use of the CXB3590.

  1. The typical forward voltage is 38.5V @ 3.6 Amp.
  2. Running it at 3.6 Amp makes thermal management very difficult.

I would only use a CoB if size is an issue. If you were to use some $4 1200 lumen Bridgelux EB Series Gen 2 strips you will get a much better lumens per watt ratio and thermal management would not be needed. Cost would be less per lumen but would take up about a sq. ft. of real estate strips are 11" x 1". Light uniformity would be better with the strips.

The max lm/W for the CXB3590 is 145 lm/W. The strips are 180-175 lm/W. Heatsinks and fan for the CXB3590 will add considerable cost. The CBX3590 will also loose efficiency if you do not keep the temperature down.


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