Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers

Need help to protect my 445nm diodes.

Sep 24, 2010
I have a history of killing 445nm diodes, probably $300 in the hole over a period of 5 years.
Not from too much current but from overheating or too long a duty cycle.

So I just bought one of DTR 7w NUBM44 V2 450nm Diode In 12mm Copper

I got the 12mm so I could attach a thermistor connected to a temperature relay circuit I have as close as possible to the diode, but I want to get an idea of what temperature I should use to protect the laser diode. I still plan to add more heatsink, but wanted to be able to place the sensor inside the larger heatsink and thus closer to the 12mm housing.

My goal is a fail proof 7w system, even if it lasts a few seconds before cutout that will be okay, just want a margin of safety in place for the most expensive component (the diode), but I've not enough money to experiment with how hot the module can get before failure occurs.

1. What temperature of the 12mm housing would you recommend to maximize duty cycle without compromising the laser?
2. What is the most simple solution you guys have discovered to cut off the laser? I think a 1 time use thermal fuse might be the easiest once all the other parameters are set, but for now I have a more complex temperature relay circuit I am using so I can experiment.


Well-known member
Dec 15, 2014
All you need
Is a
Good host with a large heat sink to absorb the wasted heat from the 44 .
The driver should be heat winked on the
CU or thermal epoxy the driver on the back of the main heat sink
If you need a host PM me
Your duty cycle should be 30 sec on and 45 sec off
We use these diodes over from what they are original for