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Help identifying diodes

Dusty_Lenses

Member
Joined
Apr 15, 2022
Messages
65
Points
18
Yea the divergence is quite aggressive, you could be losing some of your output at the edges, you'll find out when you test with a G2 lens.

I also tested in the block before extraction with the factory gang lens and got a low reading, like 4W, then I cleaned the gang lens with a Zeiss wipe and all the power was there, 6.5W, it's amazing how much loss there is from just touching a lens with our hands and I like to keep my hands clean, still it makes a big difference.

One more question regarding these nubm47's

So I got one installed on a laser engraving machine. Nothing special, its a run of the mill generics that was advertised as being 2.5W and was only outputting 1.2W and blew at 2.1W.

I turned the trimmer up on the PCB and was feeding the new 47 LD IIRC 5.2A. It was running fine, then poof! I got a single 30 second run out of it. Even added sufficient cooling for it,

Pulled it apart and its the diode thats blown, not the driver.

So my question, what should I set the LD current to? Im assuming that the TTL blanking and max current was just too much stress.

Anybody have experience with this?
 



RedCowboy

Well-known member
Joined
Jul 10, 2015
Messages
12,168
Points
113
For steady use in a decent heat sink I wouldn't go past 3.5 - 4.0A because there is a heat bottleneck at the diode and for short duty cycle use such as a pointer no more than 4.5A otherwise waste heat builds up and reduces your output, you want your output to be stable which it will be @ 3.5A - 4.0A in a good heat sink, something with fins and a fan will really let you run continuously.
 

Dusty_Lenses

Member
Joined
Apr 15, 2022
Messages
65
Points
18
For steady use in a decent heat sink I wouldn't go past 3.5 - 4.0A because there is a heat bottleneck at the diode and for short duty cycle use such as a pointer no more than 4.5A otherwise waste heat builds up and reduces your output, you want your output to be stable which it will be @ 3.5A - 4.0A in a good heat sink, something with fins and a fan will really let you run continuously.
I think I may have overshot the current big time. This "benbox" software is super buggy. The intensity setting for high output will produce different currents at a given value each time you change the value. So where I had tested 5.1-5.2A there may have been much greater spikes.

Ive got it set now to 3.6A with a G9 lens, and added a current monitor to see how it goes. So far so good, it hasn't gone past the 3.6A.
I'd crank it up a little more, but dont want to risk another diode.

Edit-

I added one of those small yet powerful fans from the a-140. Albeit noisy, its keeping the exterior nice and cool.
 

RedCowboy

Well-known member
Joined
Jul 10, 2015
Messages
12,168
Points
113
You can also use a 5W laser diode with a replaced window can and backfill that has the addition of a FAC lens installed or if you want some serious cutting power with improved beam profile then check out this 20W beauty using 4 corrected 5W laser diodes.


There's a teardown by smackitup here > https://laserpointerforums.com/thre...00-laser-module-tear-down.109530/post-1612498
 




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