# Thread: Driver for Laser question

1. ## Driver for Laser question

Hello all,
I am new to the flashlight and laser modding world and I know that this question will probably make some of the pros laugh, so be gentle.
My question is, are drivers for lasers the same as drivers for flashlights or LEDs? For example, if I had a 3v 900 mah driver for an LED, then hypothetically, if I had a laser requiring theose same numbers, I could use the same driver. Or do lasers need a different type of voltage and current regulator? Thanks in advance for any help.

2. ## Re: Driver for Laser question

hypothetically, yes you can do that. As with LEDs, laser diodes are easier to control with constant current. Keep in mind, though, LEDs are pretty robust devices in comparison to laser diodes. You may want to put it on an o-scope to make sure it doesn't spit out any startup or shutdown spikes, or possibly put a cap on the output to filter.

3. ## Re: Driver for Laser question

voltage wise, you are ok, current however is different story, just like the led if you put too much you'll burn it, what wattage is your leaser rated at??? (lasers are rated by miliwatts\watts, not ma\A like leds), knowing wattage, and voltage (3v) you can figure the current you need.

4. ## Re: Driver for Laser question

what wattage is your leaser rated at???
I don't have a particular laser yet, as I am working on understanding how to choose the proper components first, so both of these replies helped a lot.
knowing wattage, and voltage (3v) you can figure the current you need.
I think this is what I need to know. Could you tell me the formula to figure this, or point me in the right direction?

I saw in the intro to modding flashlights thread that voltage x current = watts, so could I apply wattage / voltage to find the current needed for the laser?

Using a 100mW laser requiring 3v as an example, would the current draw be around 30mA? And stepping up to 250mW at the same voltage would be around 80mA?
Thanks a lot for the help.
Bigpal

5. ## Re: Driver for Laser question

having used lasers in few builds, i recommend buying laser module with driver made for that particular laser diode, if you were building very powerful laser, it would be one thing, but for modules up to 200mw, it doesn't pay to buy diode and other components apart, get module that has driver, heatsink, lens all in one. they are widely available and cheap, save yourself time, money and burned components.
also imo the best place to learn about lasers would be laser forums, here there aren't as many fanatics of lasers as on those forums, flashlights-yes, defiantly, lasers- not really.

oh, the formula is the ohms law.

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