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View Full Version : Making my own LED.......


dave1234
Jun 3, 2003, 06:26 PM
Ok so I wanna make my own LED flashlight, this is not for my computer at all, I was wondering if anyone knows anything about making them.So yeah.......:)

tpjunkie
Jun 3, 2003, 10:04 PM
I hope you mean you need help building the flashlight (housing, case, etc) and not an actual LED, as that would probably be rather difficult for the average person to do in their basement...

mrjamin
Jun 4, 2003, 04:31 AM
Originally posted by tpjunkie
I hope you mean you need help building the flashlight (housing, case, etc) and not an actual LED, as that would probably be rather difficult for the average person to do in their basement...

errr, yes, very difficult.

You could try for the credit card sized ones? just get a couple of cards (advantage cards or whatever) and see if you can get it all inbetween them

dave1234
Jun 4, 2003, 12:53 PM
Im going to get a gulb and a battery and such from radio shack, but i don't know what "type" of bulb and battery to get. Also for the casing, what are some good ideas?:confused:

mrjamin
Jun 4, 2003, 03:16 PM
Originally posted by dave1234
Im going to get a gulb and a battery and such from radio shack, but i don't know what "type" of bulb and battery to get. Also for the casing, what are some good ideas?:confused:

you don't want a bulb - you want an LED - believe me, the two are VERY different and operate in completely different ways. LEDs are similar to pixels in a display, just bigger, much brighter and only one colour.

The best ones for a torch would be a white LED or a Blue LED - they're quite expensive, about 1 ($1.33?) a piece in the UK (regular green/red/orange LEDs are usually about 7p (13c?). As for a batter, a flat watch style battery should do the trick; if you're going to use a 1.5v AA/AAA battery you'll definately want a resistor in there too, the value you'll need is probably round about 100ohms since the maximum current an LED can take is about 2.7mA. ideally you'll need to keep it bright, but not too bright that it runs your battery down really quick. so if you keey the current at 2mA:

resistance = voltage/current
resistance = 1.5/0.02 = 75ohms

One thing that might be worth looking into, is putting an a-stable (part number LM3909 is ideal) in there to pulse the current to the LED. Say for example you set the LED to turn on/off every 10 milliseconds or so, you'd double your battery life and you barely see the flicker.

My electronics is quite sketchy since i haven't done anything like this for a few years now.

AS for housing, you're on your own on that one, no ideas i'm afraid unless you got for the watch batter and credit cards approach.

dave1234
Jun 4, 2003, 04:08 PM
So, any kind of flat watch style batter? or is there a certain kind?
And with the asatble, is there a way to make it flash between on/off between longer periods of time(like 4 or 5 or 6 times a sec?).
Still looking for housing ideas. Explain the credit card one again please.

firewizard
Jun 4, 2003, 04:37 PM
a good idea for houseing one of my buddies used for an led flashlight is a mini maglight, the led fits right in where the regular bulb goes(you need to get a certain kind) ill ask him about it, for battery he used 3 small like weird mini AA batteries or somethin like that and used a plug which had all the resistor and stuff.

just an idea

more lookin into though

kettle
Jun 5, 2003, 07:21 PM
just don't get caught selling it! :confused:

mrjamin
Jun 5, 2003, 07:22 PM
Originally posted by kettle
just don't get caught selling it! :confused:

why not? whats so dodgy about LED torches? Ok, laser pens i can see your point, but an LED is no more dangerous than a regular flashlight! they use LED's in traffic lights in the UK now!