Comments on: Poorman’s Buck – High Power LED driver

By: Hahihula

Hahihula — Thu, 24 Apr 2014 12:52:05 +0000

Hi,
I really appreciate the led source. I would be glad if you could post equations for calculating the sense resistor value, and inductor value?
Thanks

By: Greg

Greg — Sun, 02 Mar 2014 18:03:05 +0000

Hi, thanks for publishing this great circuit! In the Instructables you mention that the potentiometer can be replaced with resistors. How would you calculate the required sizes?

Thanks,

Greg

By: electroman

electroman — Thu, 02 Jan 2014 19:51:39 +0000

I believe it will cause losses..and simply won’t work… I wish it was like capacitors..the bigger..the better.. :-D

By: The LED Artist

The LED Artist — Fri, 20 Dec 2013 17:08:48 +0000

1000 uH would be too big. I’d only go as high as 100 uH.

Aki

By: electroman

electroman — Fri, 20 Dec 2013 15:48:02 +0000

can I use a bigger inductor? Its tough to find inductor in single quantities.
I have 1000 and 3000uh

By: The LED Artist

The LED Artist — Fri, 13 Dec 2013 07:17:39 +0000

Sorry for super late reply.
Yes you can just use one comparator to do the job if you don’t need PWM input.
Be careful however for interference between comparators when you combine more than one driver.

Aki

By: Mayank

Mayank — Mon, 02 Dec 2013 03:48:47 +0000

Hi Aki,

Would it be possible to remove the second comparator for PWM and use 3 comparators in a LM339 to design a manual RGB driver? What would it take? Should I just remove the circuit that connects to second comparator and the diode at the output?

Thanks
Mayank

By: Richard

Richard — Fri, 15 Mar 2013 02:35:10 +0000

I’ve been trying to find some high power led drivers that are relatively inexpensive. Can you point me too them? I thinking under $10 each as being inexpensive. I was going to try to have some pcb done up of the poormans buck but the gerber files I got from instructables don’t seem to work. with OSH Park. My plan is to use either multiple drivers to strobe a bunch of leds or to have one driver strobing them by switching the load. Any input would be nice as I’m been digging all over about LED drivers and I believe I am just scratching the surface. I was thinking of even just turning on and off the basic LM317 constant current circuit by switching its power.

Rich

By: The LED Artist

The LED Artist — Sun, 06 Jan 2013 17:19:05 +0000

I had been developing the updated version of Poorman’s Buck with higher current capability. However since there are many good buck drivers commercially available (and they are inexpensive) I don’t see the value in creating a kit.

Aki

By: philip blades

philip blades — Sun, 06 Jan 2013 11:08:51 +0000

Are you getting anymore poormans buck led drivers in. Thanks.