Some help with green module

No matter what i search for online the net keeps showing stuff from here.
I bought a 20mw green laser module from Ebay (despite the judgments on the place) and the driver board did not work properly, at all. Replacing a transistor killed any return/warranty.
With a slight mod the diode worked, but the current fluctuated between 120 and 180 ma.
All that aside, i would like to know if the LM317 circuit that i have seen on here will be good for this diode.
It is for a club laser that used to run from helium neon tube and i replaced it with a green laser pen with plenty of cooling but after the fifth event it eventually died, now i have this heatsinked module and want to make my own supply that will be effecient.
A smooth start and spike protection would be nice.
Also, i have no idea and cannot find in this forum the current requirements for a green laser, the suggested supply was 3vdc and it would be run from a mains supply which will provide 1.8v@ 120ma,, any good?
Either way, all help will be appreciated.
And thank god or whoever for this place, and hello. from a 40 year old noob.

Welcome to the forum, you are starting off at the difficult end of the hobby, was the module supplied by a separate driver unit, connected by 2 wires?  If it is the one I have come across I found the driver very unreliable, I have binned all the drivers of that type.

You should be able to use the LM317 (DDL) circuit to drive the IR pump diode, the problem is knowing how many ma to give it, the small pen type modules can vary between 200 and 300ma.

I would suggest that you build the circuit with a 100 ohm pot and a 3.3 ohm resitor ( 3 X 10 ohm in parallel) which will give a max of around 380ma.

It will be easy to overdrive the LD/crystal set so once you reach the lase point go carefully and moniter the ma with a 1 ohm resistor connected between the power supply and the driver circuit.

I have used a mains adaptor successfully in the past but the one you have mentioned will not do this job, you need to look for a 5vDc one as the LM317 needs 3volts overhead to regulate.

Hope that helps.

Regards rog8811

Yes, it's the two wire one, i will take your advice on the circuit and give that a go.
By the way, what is "lase point"? I've seen this word while i have been looking all over the internet for a driver circuit.
Thanks for the help, and thanks for the welcome.

By the way, what is "lase point"?

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The point at which the module emits green light.
Good luck with the build, to help you here is the circuit, just add another resistor to the two shown....

Regards rog8811

By the way, what is "lase point"?

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darkface, I believe he is referring to the point at which the LD stops acting like an LED, and starts acting like a laser.

For a green DPSS, getting laser light from the 808nm IR LD is only the first part of the process (is used to pump solid-state crystal laser, which outputs 1064nm IR light, which goes into a SHG "doubler" crystal, which converts that to 532nm green laser light), so I don't think you're going to see much of anything until you crank it up high enough to get the IR LD inside it to lase. Just be careful after that point.

@rog8811 -

Me again, i got it going but due to a lack of components i used a circuit from Sams Laser page, it's based on the LM317 as well but just a bit different.
First the power supply was thrown together which was also based on the LM317 and i adjusted the output to 7.2v, then fed that to the other board etc etc
Adjustment of the pot on the driver board (which was infact a preset) was smooth and precise, watched the diodes output through my mobile phone camera and noticed loads of IR, anyway, kept turning the preset until i had a nice green beam, current was about 250ma.
Now i'm going to etch a pcb, build it up and get it into it's case.
With all the IR coming out kind of bluey violetish can i just use a filter to stop it?
I have seen a small square IR filter for £4.99, if i buy this can i just mount it on the end of the laser?
I can't post pics/links as i'm not worthy yet lol but it would of been good to show you the whole thing, mainly to see if you recognise it.
It's a 20mw module from Virtual Village, they still have them on Ebay right now if you want to look, they also offered me a discount if i buy another one so i might take advantage of that.
Thanks for all your help.

Glad you got it working, another 7 posts then we can get to see it. I assume you have set the first LM317 up as constant voltage which drives another LM317 which is constant current?
As to the IR filter, I have seen a couple of posts where retro-fitting has been discussed, I have never done it myself. When you search remember to change the search period to 3 months or a year.

Here is a link to VV for anyone who is interested.
http://www.virtualvillage.co.uk/Ite...le=20mW 532nm Laser Diode Module Green NEW DJ

I love the way that they are uk@virtualvillage with the postal address in china

Regards rog8811

rog8811 said:

Glad you got it working, another 7 posts then we can get to see it. I assume you have set the first LM317 up as constant voltage which drives another LM317 which is constant current?

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Spot on, thats the exact method i chose, they do get hot though, i can't find my good heatsinks, might have to modify one from my old amp heatsinks.
I'll search for the stuff to do with the IR filter, i find the fact you can't see it quite scary.
Also, it is true about Virtual Village, uk email addy but the shipping addy is from China???
Either way, fast shipping and good on the customer service and thats the module you found, shame about the driver board, think i got a better one now though.
Cheers