little led help

[The Car Stereo Company]

ok guys, finally got time to work on one of my many projects that have been put on hold. i need an led expert to show me straight. i have 3 watt cob leds and need to figure out the math for the proper resistor. i also have 10watt cob for the same thing. if any of you know the mathematical formula or (better yet) do the math for me, i would appreciate it. you can call or text me at (831) 254-7562 with the info too.

 

[andreb]

TCSC,

You can't just hook up resistor in series to drop the V+ for a hi-watt LED like yours. You need a regulated power supply as LED's are very picky about what drives them when they are high-watt. Check out Fry's or Mouser online. This vid does a great job of explaining the details: https://www.youtube.com/watch?v=piET0Biqo0I

 

[The Car Stereo Company]

thanks. i was experimenting with the 10watt leds and it seems the resistor i was using works pretty well. 50watt 6 ohm for 2 of them. but thats connected directly to a battery. not a running vehicle, so i think a bit more trial and error and i should have it down good