more noob questions how to pick LEDs for flashlights

5/9/2006

i bought these LEDs
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7605817579
i got screwed on the free resistors tho.

the first light i need to repair is my 18v Black and Decker
5 lights in series is 3.6v each so i only need to limit the current correct?
can someone help me with the formula for the correct paralell resistor?






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original post
i was thinking of buying some LEDs to mod some flashlights..
i serched "Nichia" at digi-key and Mouser with no result.

was hoping to buy a bag of 50 or so inexpensively
but theres so many to choose from i dont kno where to start..

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7603946622
are these any good?

theres some 130,000 mcd leds on ebay are those easy to work with? need heatsinks?

my plan is to series 5 for my 18v black and Decker? sound right? or maybe just 4?

http://i13.photobucket.com/albums/a284/photoduude/battery.jpg

heres some batteries i have been planning to make lights with..and my cordless driver should be able to support a LED
no? with a momentary switch? it has a nice 3.6v battery of some kind in it and a charger so it NEEDS a bright LED added to it...just begging for it.

the 12V brick came from a near free after rebate UPS... my orignal plan was to a make a battery powered computer
frmo a mATX board but...anyone know how to do that?
i have a 5" LCD display for PSX thats said to be mod'able for 640 VGA.. ...or i can just jam the thing into my Dorcy 6v lantern battery and run LEDs forever between charge.

Re: how to pick LEDs for flashlights

i'm also interested in 555 pwm to extend the battery life
but i dont know much electronics really ..is there a guide for dummies?

i know one common sense type change to extend battery is a momentary switch ...the biggest cause of alot of dead batteries is leaving it on unintentionally.

Re: noob questions how to pick LEDs for flashlights

bump

Re: noob questions how to pick LEDs for flashlights

and do flashing leds flash fast enough to
have a pwm-like power saving effect? u know reducing the duty cycle to save power..

Re: noob questions how to pick LEDs for flashlights

last question: no.

You need a 300 flashes/sec (neon tube) not to notice the flashes.

2 cells need a booster to pump up the voltage.
Best way to save power is to use several output levels.

Re: noob questions how to pick LEDs for flashlights

bump for stuff added to my orignal post..

Re: noob questions how to pick LEDs for flashlights

Nichia sells in 100 led lots.
http://store.nichia.com/index.asp?PageAction=VIEWPROD&ProdID=138

You can try these.
http://cgi.ebay.com/ebaymotors/New-...cmdZViewItemQQcategoryZ33713QQitemZ8057642607

Reviews on leds.
http://candlepowerforums.com/vb/showthread.php?t=89607
http://candlepowerforums.com/vb/showthread.php?t=89759

thanks for the links..



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