PDA

View Full Version : Breadfan's LED tester


Breadfan
03-27-2007, 08:47 PM
This may be handy for some LED based projects...thought I'd share, and also to prove I do use things out of my boxes of salvaged electrical components!

I had a box of unmarked LED's, most of them were obvious as to what color they were, but I had a pile of clear LED's that were unknown as to what color they were.

Since most LED's run on around 3v, I found some spare parts in my electronics boxes, 2 AA batteries, and made an LED tester.

The batteries are in series routed to an on-off slider switch, which is connected to a salvaged 2-prong computer connector that makes the ideal plug for LED leads.

http://www.neuralimpulse.com/images/100_0835003.jpg

I found a generic black box and stuffed it in there, cutting holes in the side for the on/off switch and test lead. The AA batteries should last quite awhile testing LEDs.

http://www.neuralimpulse.com/images/100_0837005.jpg

http://www.neuralimpulse.com/images/100_0838006.jpg

Sorry for the blurry pics, I should've switched camera to Macro mode... :(

Oh and most of those clears were unremarkable green's...not more rare blue or white, and not super brights.
Drewstang
03-28-2007, 07:47 AM
My multi-meter has a function were I can test LED's. I think I paid $10 for it at a Flea Market. Not a bad setup you have there either.
Breadfan
03-28-2007, 08:00 AM
When I finished i found a slider reheostat switch, I think I'll make a v2.0 with a slider to range from 0v to 6v that way I can test LED's from the small 1.5v to 5v ones.
Drewstang
03-28-2007, 08:55 AM
I'm planning on sitting down and making my own LED emergency lights so I won't have to spend $500-600 when I get back on the Volunteer F.D. I found bulk red LED's with the resistors on ebay for cheap.
omarauder
03-28-2007, 12:28 PM
I would limit the current to the LED with a resistor to prevent burning it out. They're usually happy with 20 milliamps or so. If you know its part number you can usually find the spec sheet online.
Red ones usually require about 1.2 volts, Green about 2.0 volts (I'm guessing on this one), and Blue & White are about 3.0 volts.
regards