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DX 5mW keychain green (3xLR44) mini-review

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chimo

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So if you were wondering what's inside a DX 5mW 3xLR44 green laserpointer, wonder no more. This thing draws about 220mA on fresh LR44s (AG13). That kills the batteries in no time.  

I opened it by:
1. first unscrewing the rounded top end.
2. I used a small metal rod in my drill press to push the module out from the battery side.  I used the drilled/spilt piece of wood to support the tube shoulders when I pressed it out.
3.  There was no glue.

The re-assembled pointer
img0539smalldn9.jpg


PCB pot side (yes, the pot does work!)
pcbpotsidesmallle2.jpg


PCB Switch side
pcbswsidesmalltf0.jpg


The focusing barrel was very loose (which may account for the intermittant output problem for some)
pcbswside1smallse3.jpg


Side view of the crystal
side1smallkq4.jpg


Top View of the crystal
topsmallwj1.jpg


I have a couple of 10180 Li-ion cells coming that I hope will provide better run-time.

The 10180s have arrived!  It fits OK and works well.  Current was 290mA for a cell at 3.8V and 4.17V (open circuit voltages).
img0604smallrf1.jpg
 





Chimo --
This looks like the insides of my 10 mW keychain laser. I took mine apart because the LD was loose and needed some tightening. Using a bench supply, I turned mine up to 280 mA (30 mW) and put it back together --- Killed the cells NOW !! I turned it back to 220 mA.

We have to find better batteries !!!

Mike
 
Mike, I am hoping the 10180 Li-ions I have will provide a better run-time. They are only supposed to be 90mAh, so the draw will be slightly over 2C. The AG13s (LR44s) seem to come in a range of 140-175mAh, however, that capacity is measured at a fraction of a mA. I'm hoping the Li-ion will fare better. The Li-ion will be 1.8mm longer - I may have to modify the end cap/spring a bit.

I ordered them from AW in the CPFMarketplace (under the Dealer forum).

Hemlock Mike said:
Chimo --
This looks like the insides of my 10 mW keychain laser.  I took mine apart because the LD was loose and needed some tightening.  Using a bench supply, I turned mine up to 280 mA (30 mW)  and put it back together --- Killed the cells NOW !!  I turned it back to 220 mA.

We have to find better batteries !!!

Mike
Click to expand...
 
I have the 10 mW variety of this pointer (sku 7416) and found it to be completely useless with AG13 batteries, they die within minutes. So I got brave and put a 10180 Li-ion battery in there...
Wow. That little thing got brighter by a magnitude, certainly more than 10 mW, current draw from the Li-ion (fully charged to 4.15V) was close to 400 mA. I doubt that the laser can take this much current for a longer time though.

Btw, the 10180 fits in there perfectly, no modification required.
 
That's great to know! Perhaps I will lower the drive current when I use the 10180.

quantile said:
I have the 10 mW variety of this pointer (sku 7416) and found it to be completely useless with AG13 batteries, they die within minutes. So I got brave and put a 10180 Li-ion battery in there...
Wow. That little thing got brighter by a magnitude, certainly more than 10 mW, current draw from the Li-ion (fully charged to 4.15V) was close to 400 mA. I doubt that the laser can take this much current for a longer time though.

Btw, the 10180 fits in there perfectly, no modification required.
Click to expand...
 
The 10180s have arrived.  See 1st post for the pic.

The regulation seems to work. The current was 290mA for a partially depleted (3.8V non-loaded) and a freshly charged one (4.17V non-loaded).
 
MarioMaster said:
looks like a good alternative to button cells  :)
Click to expand...

Yes, the volume of the casings of those button shells constitute to a lot of wastage in comparison to their overall volume.
 
It was a little bright at 290mA so I dropped the drive current to around 200mA to make it more suitable as a pointer for presentations and it should also extend run-time.
 
chimo said:
Mike, I am hoping the 10180 Li-ions I have will provide a better run-time.  They are only supposed to be 90mAh, so the draw will be slightly over 2C.  The AG13s (LR44s) seem to come in a range of 140-175mAh, however, that capacity is measured at a fraction of a mA.  I'm hoping the Li-ion will fare better.  The Li-ion will be 1.8mm longer - I may have to modify the end cap/spring a bit.

I ordered them from AW in the CPFMarketplace (under the Dealer forum).

[quote author=Hemlock Mike link=1198035577/0#1 date=1198040125]Chimo --
This looks like the insides of my 10 mW keychain laser.  I took mine apart because the LD was loose and needed some tightening.  Using a bench supply, I turned mine up to 280 mA (30 mW)  and put it back together --- Killed the cells NOW !!  I turned it back to 220 mA.

We have to find better batteries !!!

Mike
Click to expand...
[/quote]
how much is the battery cost?from where i can buy it?
 
Wait? your running your key chain off of regular batteries!?

Make a video of how it works please.
 
Is there any chance the OP would be willing to post pics of how he removed the module? I want one of these in the worst way, but I only want 2-3mw after I'm running a 10180.

If I try to fix it on my own, I WILL break it lol
 
OK this battery seems to be the perfect solution to the power requirements for this laser. However, how in gods name are you planning on charging that teenie thing???!?!?!?
 
Good question. Special order charger or jerry-rigged regular charger?

quantile said:
current draw from the Li-ion (fully charged to 4.15V) was close to 400 mA.
Click to expand...

That's only double the rating. It'll be fine ::)

Good luck! :)
 
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