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How to wire this laser? Answered

Hey Guys,

I recently needed a laser for a project and as the electronics store had none i thought why non to extract one from a cheap laser diode. So....i got a laser peeled back the casing and got it. But the problem is that it doesnt work. Most probably because one of the contacts doesnt seem to be attached to the laser. Pics have been uploaded. Not that the lower contact doesnt seem to be connected with the rest (p.s it had a spring which used to come in contact with the underside of the button cells. I was wondering if any of you could help me.

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Josehf Murchison

Best Answer 4 years ago

That looks like a pointer Laser.

If it is + positive goes to the chrome plated plastic.

- negative goes to the circuit board in the through hole closest to the chrome plated plastic.

They take 3 #LR44 batteries that should be 4.5 volts.

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rickharris

4 years ago

Possibly Downunder35m means something like this

laser.jpg
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Downunder35m

4 years ago

If it is from a coin battery operated one, the middle contact is most likely negative, positive usually on the metal parts of the laser diode.
Looks like yours had a little push button between - the remaing two connections.
Most pointers I salvaged will work this way:
Nagtive on the centre contact, from there over the switch and back to positive through the housing of the laser diode.

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SA-DIYDownunder35m

Answer 4 years ago

Whats the centre contact? The lower or upper

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SA-DIYSA-DIY

Answer 4 years ago

Can you explain this more thoroughly?

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Downunder35mSA-DIY

Answer 4 years ago

What is there to explain?
Where the holes are there was a switch, the spring for the battery was soldered on in the middle of the circuit board - as they sit behind it "center" is quite obvious, especially if you cinsider the missing switch.

Just looking at your last image should make it obvious, but if don't understand it you might be better off buying a new one - or to pay more attention when taking things apart.

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ptkrf

4 years ago

If I were you, I would take a PSU and connect around 3v to two random connectors. Laser diode acts much like regular diode - it only glows if voltage is applied in right direction and if you connect wrong two leads, it won't glow. If your laser has three pins, one is not connected and you won't hurt your laser if you power it. Just try them all out.

Important thing however is not to keep laser powered for too long as it will get damaged if it overheats.

If it won't glow under 3V, try 5V. You can try higher voltages as well but if it doesn't glow at 5V, there is a big chance that your laser diode is dead...