DIY LED driver from random spare parts 11

Ordered a bunch of AMC7135 *current* regulators from AliExpress (can’t seem to find anyone that manufactures them on major distributors) and wired it up with the recommended circuit on the datasheet. Potted the whole lot in UV resin because I didn’t have a PCB to mount the components to (who needs traces anyways if you have component leads)

The current regulator regulates to approximately 350mA with a range of input voltages; the CSP LEDs mounted on the MCPCB can apprently handle 1.4A each but since I did bodge them onto the wrong footprint, I decided to just go for a relatively low current (there are LED torch drivers simply running multiple of them in parallel so they should scale mostly linearly).



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11 Comments

  1. Love it but u might need to put a few layers on the led before it catches a cold

  2. This seems… very overkill

    Nice!

  3. Heated heat sync never runs outta heat!

  4. finally a good use for the shitty stock intel coolers

  5. Forgot to mention: the LEDs were simply being used to test the driver at its limit and since I didn’t want to risk them burning you stuck it to an unused heatsink (it’s actually a random one harvested from an old university PC but isn’t made by Intel for some reason)

  6. You keep that intel fan on to keep it cool?

  7. Styro pyro buying anything

  8. what the heck is that cooling?! what is that led running on? mains?!?!?!

  9. Nice.

    when you mention not finding them, do you mean that particular driver or similar constant current LED drivers?

  10. There are 100W+ LEDs out there that would use a heatsink like this.

    Check out Yuji LED if you want to see high power white LEDs with a high CRI (color rendering index). I have 2 of 100W LEDs, they are pretty neat.

  11. I’m not sure what you are aiming to achieve here but I have worked in this space and learned a number of useful things.

    First, there are constant current drivers easily available and they can be be easily adjusted to different currents. I honestly don’t see any reason to make your own CC driver when those are widely available. For example [https://www.amazon.com/LD24AJTA-Adjustable-Controller-Step-Down-Converter/dp/B08T9JJW6Y](https://www.amazon.com/LD24AJTA-Adjustable-Controller-Step-Down-Converter/dp/B08T9JJW6Y) I use surface mount resistors (replacing the default one) to change the current limit.

    Second, as others mention, that’s more heat sink than you need. If you’re doing 10-20W LEDs, you can use a heatsink like this: [https://www.amazon.com/gp/product/B08L7PLDLX](https://www.amazon.com/gp/product/B08L7PLDLX) . I run those at full power and while the sink gets hot, the LEDs are just fine. In fact, the clamping of the LED to the surface (with thermal glue or wires) is just as important as the size of the heatsink; if you aren’t making good contact, the LED won’t transfer heat to the sink effectively and will overheat and die.

    Third, I recommend PWMing that current driver and running at about 50-75% max. LEDs run FAR cooler but are still plenty bright.

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