Ok...I got some LEDs. Now what?

Ok, I got a package of 10 ultra bright 3mm LEDs, 5 powered 5mm LEDs, and 1 powered 10mm LED. Now what? I have a solitaire and a 6 AA Energizer Double Barrelled I wish to upgrade, some of those mn21/23 (you know what I mean) batteries from wal-mart. What can I do as far as simple upgrades? How important is polarity? I have no multimeter or anything fancy like that. Will that 10mm powered LED work as a direct replacement for my dead Bi-pin bulbs in the double barrel since it's two sets of 3 AAs? And how about for a Mini-Mag?

:bump:


Or can anyone point me to some applicable threads?

I'll give it a stab... Polarity is very important with LEDs... they won't work if reversed.

Depending on the Vf of the LED, they may or may not work on 2 alkaline cells. Most green, blue and white LEDs have a Vf of around 3.4-3.7V and so will usually work on the 2.4-3.0V of two alkaline or NiMH cells but not quite as brightly as if pushed to full spec. This is one of the reasons the MJLEDs are so popular... two fresh alkaline cells drives them VERY well.

Often red, yellow and amber LEDs will smoke if run on 2 alkaline cells as their Vf is usually around 2.0-2.4V

Assuming your LEDs are all white, then should all run on 2 cells, but possibly not to their full brightness. As far as the Double Barrel... you're on your own. If we don't know exactly which LEDs you have, we can't advise you on them. If they are the Nichia CS LEDs, they should do very well.

Hope this helps... feel free to ask anything else.

Quickbeam's site has a section on mods. I see a bunch of solitaire and a couple of double barrel mods there.
http://www.flashlightreviews.com/mods/mods_index.htm

Try searching CPF for SOLITAIRE and DOUBLE BARREL under the Homemade and Modified Lights forum.. You might get lucky.

I'd think it best to have at least a basic multimeter just to know what voltages you are dealing with. You can also use it to get your polarity correct.

I wish I were familiar with the lights you have but this is the best I can do. I am not an electrical guro by ANY means, this is just what I learned from web resources and my own tinkering.

Basically, you want to find out how much voltage your light is feeding the built-in LED/Incan bulb. That's where the multimeter comes in handy. Then, find out what the Vf (Forward Voltage) and If (Forward Current) values for the LEDs you bought. Plug in the #'s into a resistance calculator to find out if a resistor is needed. Then you can solder it all together!

Here are sites with basic info on how to hook everything up: http://www.mindspring.com/~jeffpo/ledlite.htm and http://www.pbase.com/dloftus/led_flashlight_bulb

Happy modding and post the progress!

Ah! Thanks guys, and these are the LEDs I got from LCK LED STORE:

Products1 x10mm Powered White LEDs
http://www.lck-led.com/product_info.php?cPath=22_24&products_id=50



5 x5mm Powered White LEDs - Quantity Discount: 5-9 PACK - 4%OFFhttp://www.lck-led.com/product_info.php?products_id=122

1 x3mm Ultra Bright White Leds - 12000mcd - 10PCS
http://www.lck-led.com/product_info.php?cPath=1&products_id=36

OK... yeah, any of those should run on two cells but probably not to full brightness. Running on three cells... I'd imagine the 5 and 10mm LEDs could take it fine... I'm not 100% sure on the 3mm but since you have 10 of the 3mms, it's not like it would be a big risk. Just pup it in place and apply two fresh alkalines. If it starts to flicker very fast, it's probably getting ready to die. Or it might just burn out and you'll be able to smell the burning. Obviously that would mean it didn't work very well.

My personal experience is most of the non-Nichia CS 5mm leds run pretty close to full brightness on just 2 cells but the '13 lumen' 8mm and 10mm LEDs are unimpressive on only two cells.