drive high power LED with high supply voltage

Thread Starter


Joined Oct 12, 2009
i need some help to drive high power led of 1 W each in a string of 30. it has a supply voltage of 160v dc and Vf of LED's is 4.5 at 4Amps .
LM317 has 1.5A current limit. can anyone suggest high current limiting voltage regulator for high supply voltage.

thanks in advance


Joined Jul 17, 2007
Well, your best bet would probably be a 4A synchronous buck current regulator. Don't have any schematics for you offhand.

We generally like to have our new members stay with projects that involve less than 50v for safety reasons.

How much experience do you have with electronics?


Joined Mar 24, 2008
Could you show a schematic and a data sheet for the LEDs and the circuit? I know they exist, but 4A for an LED still sounds a bit high. Wookie's right about the shock hazzard, be very careful.

When it comes to current limiting there are lots of ways to do it. In your case you're dealing with both extreme amps and volts, which translates as heat, almost always.