Dim Laser

[hlokk]

I bought a green laser pointer a while ago. Certainly an awesome finder tool for a dob...... when it works. Pretty sure its 10mW so should be plenty bright enough. However, the problem is it starts of nice and bright, then less than half a second later it goes dim :S. I dont use a scope too often and didnt get around to sorting it out when I first bought it unfortunately (so bit over a year since I bought it).

I've got lithium batteries in it, and the almost instant dimming happens in my room, or even after leaving in a pocket for half an hour, so its not because its at cold temperature. I tried leaving it on for a few minutes and it didnt seem to have any effect.

Is there anyway to fix it, is it a dud, or something else? Would be useful to get it working properly (can barely see it sometimes, but its a bit fickle)

[bmitchell82 (Brendan)]

more than likely the diode is overheating hence dissipating the beam. I know this happens to cheapy brands when you leave them on and it stuffs them.

I use a decent quality 1mW laser which is great for personal/laser guider use. For showing people upto about 5 a 10mw is fine, bigger than that you would look at a 20-30mW problem is its generally illigal to own one over 5mW depending on the state regulations. aka Be careful.

[snowyskiesau]

I have exactly the same problem with a pointer I got from Astro Optical a few years back.
Not sure what power it is, the label just says <20mw.

If you find out what causing the problem with yours, I'd appreciate knowing.

[hlokk]

Originally Posted by bmitchell82

more than likely the diode is overheating hence dissipating the beam. I know this happens to cheapy brands when you leave them on and it stuffs them.

Bit odd it would overheat in a fraction of a second? I suspect its to do with the control circuitry (maybe theres a little dial, or contacts need to be cleaned?). Got it from a shop here in perth, so shouldnt be a complete cheapy (I wouldnt consider it cheap).