Mod - 15-20 mW 635nm keychain pointer

Pumped up red keychain pointer. I modded a $5.00 keychain pointer, put in a 15-20mW 635nm diode + apc supply + meredith lens.

Read the gory details here:
http://laserpointerforums.com/f42/mod-15-20-mw-635nm-keychain-26732.html

It's bright, about equivalent to a 50-60 mW 655 nm DVD diode.



Here's a beam shot in a smokless room during the day:

nice job

cool keychain. now put an open can in there. 10 seconds on, 20 minutes off duty cycle XD

jake21 said:

nice job

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Thanks. I did this just to have something to do, but I'm happier with it than I thought I'd be. There's something to be said for having a bright lil' thing in a tiny package you can slip in your pocket w/out a second thought. It's like a 15mW HeNe laser you can pocket.

VillageIdiot said:

cool keychain. now put an open can in there. 10 seconds on, 20 minutes off duty cycle XD

Click to expand...

Actually, this may be possible. No joke. It comes down to how much current those 357's can supply. I bet they might be good for 150-200mA in short bursts. Just stick a DVD burner diode in there. True mighty mite package.

I'm thinking about it.

anyone know where these 15-20mw diodes can be bought?

I wouldn't mind having a 75mW-100mW keychain laser pointer, it's always nice to have a little balloon popper/match lighter in your pocket.

flogged said:

[quote author=VillageIdiot link=1212271866/0#2 date=1212278103]cool keychain. now put an open can in there. 10 seconds on, 20 minutes off duty cycle XD

Click to expand...

Actually, this may be possible.   No joke. It comes down to how much current those 357's can supply. I bet they might be good for 150-200mA in short bursts. Just stick a DVD burner diode in there. True mighty mite package.

I'm thinking about it.
[/quote]


Button cell batteries are horrible for sort of high drain, while they would work the battery life would be very short, around 5 minutes, a much better option would be to use a very small lithium-ion cell such as the one on the far right of this picture (picture by orb at cpf)...http://www.candlepowerforums.com/vb/showthread.php?t=158970

The 10180 battery is unbeleviably tiny, it is about the exact size of three of those button cells stacked.  Even though its tiny it can still easily handle a current draw of 200ma and it would last about 30 minutes.

And here is a runtime graph with 200ma being drawn from the 10180 battery, the graph is actually for a flashlight but since the flashlight draws 200ma and uses a 10180 it is perfect for demonstrating runtime (This is a picture from ViReN at cpf)...

..lazer... ;D ;D ;D

wooooo, yes i've already looked at the lummi wee and its 10180 battery. It would be an ideal choice for a tiny laser pointer.

However you're incorrect about button cells not being able to supply the needed current. If you get the silver oxide button cells (such as Energizer 357's) they CAN handle the current drain, at least briefly. LR44 (alkaline) button cells CANNOT handle the current drain. I've tried both. Alkaline button cells will fade almost immediately, after the pointer is on for more than a few seconds. Silver oxides handle the load (90-100mA) for at least 20 minutes before starting to fade - more than enough for a little keychain pointer.

These button cells are easy to find (my old boss will sell me them for <$1 ea.), however I agree the rechargeable 10180 would be a better choice.

flogged said:

wooooo, yes i've already looked at the lummi wee and its 10180 battery. It would be an ideal choice for a tiny laser pointer.

However you're incorrect about button cells not being able to supply the needed current. If you get the silver oxide button cells (such as Energizer 357's) they CAN handle the current drain, at least briefly. LR44 (alkaline) button cells CANNOT handle the current drain. I've tried both. Alkaline button cells will fade almost immediately, after the pointer is on for more than a few seconds. Silver oxides handle the load (90-100mA) for at least 20 minutes before starting to fade - more than enough for a little keychain pointer.

These button cells are easy to find (my old boss will sell me them for <$1 ea.), however I agree the rechargeable 10180 would be a better choice.

Click to expand...

He said around 5 minutes, so at what you claim would be 10 minutes, not far off....

?? I'm getting at least 20 minutes of use from silver oxide cells. Possibly more. I've never done a test to determine. It's a lot better than 5 minutes however (lol), and the batteries can handle the load.