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How to safely power DVD laser? Answered

Hey guys!
I just wanted to know how to safely power a DVD red laser diode using 2x AAA rechargeable cells rated at 600mAh each.
I have seen some people use just a 1K resistor and the diode, but is this safe?
Thanks in advance,
IndianHacker.

Tags:Laser

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Downunder35mIndianHacker002

Answer 3 years ago

If you want more than basic power supply the laser check Ebay for Laser diode drivers.
They come really cheap and small and the better ones offer a TTL logic input that can be used to turn the laser on and off, which makes it really nice for other experiments too - plus you don't force a lot of current through a tiny switch ;)

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Downunder35m

3 years ago

There is a reason why someone invented constant current drivers for laser diodes.
If you want to play with dangerous light, go blind or worse, then you should at least know what you are doing - this part I can not see in your posting anywhere.

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IndianHacker002Downunder35m

Answer 3 years ago

Well, I do have lots of experience with diode lasers.

My question is, can the constant current driver be run from 3 volts from batteries?

Because the ideal voltage for the LM317 is 7 volts.

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steveastroukIndianHacker002

Answer 3 years ago

You need a boost converting constant current source, not an LM317. Lasers are very fussy about voltage spikes, so you need to be extremely careful there are no nasty transients on the output.

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bravoechonovember1

3 years ago

you say DVD but it has to be a DVD-RW if I remember correctly a regular reader uses IR lasers not red lasers

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steveastrouk

3 years ago

Its probably safe, but its not optimal. You may find the laser isn't pushed over its threshold voltage properly, and isn't as powerful as it should be.