Resistor 2W with LEDs

Grumpy_Mike: You are going to generate the same amount of heat with any linear regulator method. If you want to reduce the heat then you have to use a switching regulator, there are a lot harder to make because you need a good layout on a PCB to keep the circuit stable.

And just to reiterate - using a current source for the LEDs, you do not need to feed them from a voltage regulator.

I think you are misunderstanding this statement.

So again, the LM317/7812s would go away.

No, you replace it with all those transistors that generate a constant current supply.

I would not endorse the advice given by cjdelphi

He asked for suggestions... now get off your soap box

He asked for suggestions… now get off your soap box

I am most definitely open to suggestions; however, your suggestion does sound a bit risky. It may even have to be fused to avoid any malfunctions that could result in excessive heat which would destroy the circuit/create a fire. I do appreciate the suggestion though. Having several viewpoints on the matter is always beneficial.

think you are misunderstanding this statement.

I can almost guarantee that I’m misunderstanding the statement Paul__B was giving. I’m really reaching the limit of my electronics knowledge.

I’ve attached an updated file of the circuit, which separates each channel with individual TIP120s. The only good thing about this particular circuit is that not all of the channels will be running simultaneously. Either the red or the blue/white channels will be on, not both. Meaning the total heat won’t come from every single component all the time.

If the LED connected to 12V has a resistor in it then show this on the schematic.

Do not connect all the bases together, connect each one through it's own 1K resistor to the same pin of the processor.

Using a zener diode and a resistor combo like this could be an option, except you need a string of LED's...

(Fire is unlikely, but fair enough lol)

The only place you require to put up with the heat is the LED itself.

you can use mosfets and not transistors to reduce the heat at that point. you can use a swither for the voltage to reduce heat at that point as well.

of the LED's are on some bracket, that bracket could be the heat sink. and that would be removed from the electronics panel. you could mount your transistors on that bracket and use that as the heat sink.

If the LED connected to 12V has a resistor in it then show this on the schematic.

Do not connect all the bases together, connect each one through it’s own 1K resistor to the same pin of the processor.

Done and done. (attached circuit mk. VI)

Using a zener diode and a resistor combo like this could be an option, except you need a string of LED’s…

So the LEDs would go where the LOAD is listed on your schematic? What would the benefit of using the zener diode be here?

If the LED’s are on some bracket, that bracket could be the heat sink.

The LEDs will be mounted to a big (12" x 24") sheet of aluminum. I’ll also be using CPU thermal compound to help facilitate heat flow into the plate.