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Problem with a green key chain laser pointer, help

M

mega

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So I ordered a green key chain laser pointer 5mW and discovered that something is wrong with it.
It is strong for about a minute than it starts to dim. Anything after that is just really low light.
Yes it does use three LR 44 batteries but when I pull them out and test them, they still read 1.53V, all three of them. So if the batteries are ok what the heck is the problem? Is there a nice small green key chain laser pointer that would use one AAA battery?
I have seen one on DX site but it's red. If anyone knows about green one please let me know.
I'm starting to hate mine since I can't get even a decent minute out of it. I ordered a 50 pack batteries but it takes painfully long to ship them. I need to point now, please give me a link to a decent low powered green key chain laser pointer or let me know if there is any way to fix my existing one. Thank you.
 





M

Murudai

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Re: Problem with a green key chain laser pointer,

After a minute, as in you leave it on for a straight minute?

You're probably overheating the crystals. Though, a 5mW should be fine... but in higher powered green lasers leaving them on for too long damages them.
 
M

mega

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Re: Problem with a green key chain laser pointer,

Yes about a minute of continous use. Anything after that is just low light and eventually it dies. The laser itself is not getting hot.
 
M

Murudai

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Re: Problem with a green key chain laser pointer,

Yeah, I'm inclined to say that it is just hitting the duty cycle and dieing out.

But a 5mW laser is so weak that it shouldn't really have a duty cycle, that's what makes this strange...
 
H

hydrogenman15

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Re: Problem with a green key chain laser pointer,

Murudai said:
Yeah, I'm inclined to say that it is just hitting the duty cycle and dieing out.

But a 5mW laser is so weak that it shouldn't really have a duty cycle, that's what makes this strange...
Click to expand...


Could it be the driver? ::)

--hydro15
 
M

Murudai

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Re: Problem with a green key chain laser pointer,

Yeah, I thought about the driver as well.... but a DX driver being sophisticated enough to shutdown from overheating? hmm...
 
mikeeey

mikeeey

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Re: Problem with a green key chain laser pointer,

it may just be cause the laser is so small, I couldnt expect much more from a keychain laser... get a flashlight style laser if you want something that stays on for a good while, never a pen style! :D and now we've found out, never keychain style.
 
M

moond0ggie

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Re: Problem with a green key chain laser pointer,

also, measuring the voltage on a battery w/o a load on it does not tell its true ability to produce
enough power or its state of charge.
It may show the correct open circuit voltage, but drop substaintially once a load
is applied.
 
M

mega

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Re: Problem with a green key chain laser pointer,

I wish there were rechargeable button cell batteries. Obvisously there aren't any.
I'll have to start thinking about gettin a LP that uses AAA battery/ies.
 
GooeyGus

GooeyGus

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Re: Problem with a green key chain laser pointer,

This is typical of these lasers. Those batteries just cant push the pump for long at all. I've had batteries that still measured 1.5v but couldn't even put out 100mA.

That pump diode is probably running at a minimum of 150mA, and those batteries just cant support that kind of load for over a minute or so. I remember someone else on the forum buying one and the same thing happened. He eventually found a Li-Ion battery that would fit, that lasted much longer.
 
M

mega

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Re: Problem with a green key chain laser pointer,

I guess I'm going for this laser. http://www.dealextreme.com/details.dx/sku.2511  
That way I don't have to worry about button cell batteries any more.  I want a nice small laser that isn't too powerfull and lasts longer than those lousy key chain laser pointers.
Do you guys think it's a good pick?
 
M

moond0ggie

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Re: Problem with a green key chain laser pointer,

Thats a bit pricey, $30. for 5mW....................................but its seems the only one that fits your
criteria of small size & low power. It looks well built!
 
mikeeey

mikeeey

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Re: Problem with a green key chain laser pointer,

mega said:
I guess I'm going for this laser.   http://www.dealextreme.com/details.dx/sku.2511  
That way I don't have to worry about button cell batteries any more.  I want a nice small laser that isn't too powerfull and lasts longer than those lousy key chain laser pointers.
Do you guys think it's a good pick?
Click to expand...
actually I suggest you get this one:
http://www.dealextreme.com/details.dx/sku.11018

I have this laser, It's the same size as the one you have linked, but it's cheaper and more powerful. I ordered another for my girlfriend's dad. He mounted his on his rifle lol. He says it's working fine.
I think you would like this one much better. I too was actually in your spot, looking for a keychain laser, and then I ended up with this one!
 
M

mega

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Re: Problem with a green key chain laser pointer,

Thanks for your suggestion. The laser that you linked is the one I was eyeing for a quite some time. However I decided to go for the one that looks the same (except it's silver) and it's only 5 mW. Here is the link for the one I'm getting. http://www.dealextreme.com/details.dx/sku.2511 The reason I went for this one is that it's relatively small, doesn't use button cells, its' relativelly safe and most importantly, it should make it through the customs since the tough ban on anything stronger than 5 mW for the USA went into effect.
I hope I made a good decision. I really don't want anything stronger than 5 mW. I consider the dangers of anything stronger than 5mW unjustified. I just want something that's is reliable and safe.
I will keep my first key chain laser that I purchased a while ago as a souvenir to remind me the introduction to the world of lasers.
 
M

mega

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S

Sefrez

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Re: Problem with a green key chain laser pointer,

Why does it have to be key chain? If you don't mine me asking.

You can get real nice pointer/flashlight style ones.
 
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