Pro/Forums - View Single Post - LED Poi (Simple LED circuit advice required)

G33k · 11-25-2003, 09:42 AM

Right, the LEDs arrived last night and a quick test with some AA batteries (still waiting for the AAAs). The batteries (3 in series) gave me a little over 4v when fully charged and I was getting 0.5A through the four LEDs. So that's ~125mA per LED which is WAY too much (they were DAMN bright though!

).

The thing is, 0.5v / 80mA is only 0.625 Ohms if I'm not mistaken. That's quite a small value for a resisitor isn't it? Maybe I'm missing something here - wish I'd listened more in my electronics lectures now :/

How can I bring the current down?

11-25-2003, 09:42 AM	#6
G33k Cooling Neophyte Join Date: Sep 2002 Location: Bristol [UK] Posts: 73	Right, the LEDs arrived last night and a quick test with some AA batteries (still waiting for the AAAs). The batteries (3 in series) gave me a little over 4v when fully charged and I was getting 0.5A through the four LEDs. So that's ~125mA per LED which is WAY too much (they were DAMN bright though! ). The thing is, 0.5v / 80mA is only 0.625 Ohms if I'm not mistaken. That's quite a small value for a resisitor isn't it? Maybe I'm missing something here - wish I'd listened more in my electronics lectures now :/ How can I bring the current down? __________________ "Success is 99% Failure"