Curious behaviour by DX 91

[PlayboyJoeShmoe]

http://www.dealextreme.com/details.dx/sku.91

It always worked by being bright for a second and settling down to decent.

Today it started dimming to nothing in about 5 seconds.

I changed the batteries that came with it for some Panasonic Alks I had in the door of my truck. The same thing was happening.

I came home meaning to try some NimH, but got on a riding mower and did quite a bit of mowing.

When I got in the house I pulled it out and it was working as if nothing ever happened. I put in NimH AAAx2 and again it works as if nothing had happened.

Any thoughts?

 

[liveforphysics]

Temperature plays a big factor. The crystals and alignment can be very fussy. Some are very dim when cold, and become monsters when hot, some are visa-versa.

In reguards to batteries, there is only 1 battery to use for optimal performance. Energizer lithium primary cells (not titanium, not duracell anything, not "digital" nonsense, just LITHIUM). They are spendy, generally about $2-3 per cell. They are temperature stable, high current capable, high voltage (1.9v) chemistry, and have roughly 4 times the capacity of most other batteries.

NiMH can handle the current, but has a much lower voltage. This yeilds much lower output than lithium primary.

They are the biggest bang for the buck in a laser upgrade.

Keep the duty cycle down with them though, I only do about 10 seconds at a time with them just to ensure I don't hurt the laser.

 

[stephenmadpotato]

Yeah I agree, it could definately be the crystal assy. But don't forget to consider that the infrared pump inside could be going. If I just screwed up the terminology, my bad.

 

[PlayboyJoeShmoe]

I finally got some Lith AAA to try.

It still comes on bright for a few seconds and then dims, but it doesn't dim as much as with NimH.

Just read a comment about pen lasers on DX and that made me think about posting this.

 

[bleufan]

I have the exact same laser pointer, mine also dimmed and doesn't come up anoymore.
But, it really DOES output IR! (in my case at least). The diode probably got misaligned. And I haven't heard of a decent way to fix that.

To check if it put out IR (and thus making sure the electronics are working, point the laser close to a diffuse reflecting wall and see if you get a faint red glow (in dim light conditions) on it. That faint red glow is a heck of a lot IR! I nearly looked in to it. I saw the red glow, but thank God didn't caught the full beam.
An IR cam also works, and it confirmed the powerfull IR.

Be careful