How not to destroy my laser?

[Mutad0r]

I bought this: Industrial Lab 3VDC 532nm Green Beam Laser Lazer 30mW Diode Module | eBay

It just arrived and I decided to go over the ebay page again, just in case..

Then I noticed this sentence:

The best working method is 40 seconds continuously working and 15 seconds resting. Otherwise the laser may be burnt.

The laser is meant to be used continiously in my application, how big is the danger of burning the laser? Would it help if I used a LITTLE less than 3V, and maybe added a heatsink and a small fan?

 

[ARG]

Use exactly 3V, adding a heatsink and fan will allow for a continuous duty cycle if the airflow and surface area of the heatsink is enough. (If it gets warm turn it off)

Remember to heatsink the driver as well.

 

[Cube777]

30mW shouldn't be a problem running continiously, I can't open the eBay page right now but if there is any type of heatsink at all there shouldn't be a problem. On Lazerer there is a 100mW 532nm module that has no heatsink an it can be left on for one minute!

EDIT: ARG you beat me to it

 

[Mutad0r]

Well, I just measured its current usage at 2.9V, and it's 320 mA, so I guess the 30mW is an estimate power after the crystal?, by my calculations, the laser uses almost 1W, does that mean the infrared one inside is a 1W one?

 

[ARG]

Your laser diode is probably a 300mW, the other 700mW being drawn is released as heat in the driver/diode. Then the 300mW is pumped into the crystals and you get about 30mW out after the crystals.

 

[Mutad0r]

Ok, OH, and as for turning it off when it gets warm; is there a specific temperature range that shouldn't be exceded, my microcontroller has some free pins, I could add a thermometer and include an automatic shutdown in the code once a specific temperature is met.


EDIT:
actually, nevermind I think.. on the ebay: "+15 ~+35 centigrade", but maybe 30-33 centigrade as a turnoff point just in case?

 

[baharini]

Just add a large heatsink and it should be fine. Adding a fan is also a good idea, which should turn out great. In my build (http://laserpointerforums.com/f50/my-first-build-red-lab-laser-250mw-dvd-burner-80410.html) I added a heatsink and fan (read the update at the bottom of the page) and it can run indefinitely. And that's at 250mW.

 

[Cyparagon]

Well, I just measured its current usage at 2.9V, and it's 320 mA, so I guess the 30mW is an estimate power after the crystal?, by my calculations, the laser uses almost 1W, does that mean the infrared one inside is a 1W one?

2.9V is fine. 1V is lost in the regulator and the pump diode is somewhere around 40-50% efficient. Lasers are rated on their output power, not input power, so this will likely be a 200-300mW pump. The rest is lost in the conversion to green (and expander).

Duty cycle is copy pasta among Chinese vendors. They do no testing on this - it's a made-up value. You'll be fine running a low power device like this indefinitely.

 

[Mutad0r]

2.9V is fine. 1V is lost in the regulator and the pump diode is somewhere around 40-50% efficient. Lasers are rated on their output power, not input power, so this will likely be a 200-300mW pump. The rest is lost in the conversion to green (and expander).

Duty cycle is copy pasta among Chinese vendors. They do no testing on this - it's a made-up value. You'll be fine running a low power device like this indefinitely.

Thanks!

 

[HitShane]

So, only 60mw green pens lose power as they get warm and crash fast?

When its not the batteries dropping... Fresh change does not matter, heat does...