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Driver design (working concept)

GBD

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I built a driver to drive an LPC-815 diode recently, the only catch was that my power supply on hand pumps out 15V.
To work around this, I just make a voltage regulator out of an LM338, and then a current source style driver to provide the nessasary current to the diode.

Here is the concept of it, I just thought to share this one for those trying to find ideas on how to drive diodes from higher voltage supplies. it works fairly well IMO, but needs to be adjusted to w/e your diode/supply is.
:beer:
 
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anselm

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Re: Driver design

Sorry for not commenting directly on your circuit, I don't understand it fully....
But I am wondering, didn't you know a LM317 can take up to 30V of input?:thinking:
With a heatsink it will scoff at those 15V.
 

GBD

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Re: Driver design

I know an LM317 can do that, but the LM338 is part of the same series... and can do 5A instead of 1.5A.

That is mostly the reason I picked out that IC, is due to its current ratings.. sure for an LPC-815, an LM317 is more then enough but if I ever modify this design to run something like a 2W 445nm diode, or multi-watt IR diodes, then 5A ratings for the voltage regulator would be nice IMO. the darlington pair for the current will laugh at 5A (Im using fairly large transistors)

If you dont understand parts of the circuit, let me know, id be happy to explain them as much as I can.
 




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