9mm 445nm (NDB7875) duty cycle.

[deltawars]

I just build a 3W laser with the NDB7875 and Survival Laser Stainless Steel Host Assembly, Extended and Tapered Heat Sink, but it only has a duty cycle of 35s on and 180s off which I don't like, I worked out it is giving off 8.75W of heat, if I run it at 1A 4.4V it will have a laser output of 1.445A, and a heat output of 4.4A, would that mean that I can double the duty cycle to 70s on and 180s off?

If anyone has a C6 host, or survival laser stainless steel laser, can you please tell me what diode, voltage, current and duty cycle you are using?

Also is there a way i can workout how much heat a heatsink can hold?

 

[IsaacT]

You need to look at the specific heat of the metal, and also the weight and density of the metal. In your case it will be copper. Also keep in mind that your laser doesn't release its heat very quickly and that the transfer to the stainless steel body will be slow and very inefficient. I don't think reducing the output that much will directly double the duty cycle.

 

[deltawars]

I have just been looking at other laser diodes, and the only real difference between them is that this one has a higher output, but it is not really any more efficient with heat output, then any other diodes so it would be a waste to run it at a lower current, guess I have to buy a new host.

Do you know anywhere I can get a host like these ones or similar?

 

[IsaacT]

Talk to Mrcrouse. He is great at replica work. Alternatively put up a BST thread for broken lazeerer rifle lasers.

 

[Pi R Squared]

If anyone has a C6 host, or survival laser stainless steel laser, can you please tell me what diode, voltage, current and duty cycle you are using?

Talk to Mrcrouse. He is great at replica work. Alternatively put up a BST thread for broken lazeerer rifle lasers.

See the white links in my signature for my C6 and Survival Laser SS builds. The C6 M140 is about half the power and still has a very short duty cycle, its the price you pay to use a small host.

Mrcrouse can for sure sell you a host that fits your needs. See his many sales threads in the B/S/T section. For a laser in the 3W range you need something with a very large finned heat sink, if you want a long duty cycle then the bigger it is the better.

Alan

 

[vari]

You are running it at half the nominal power. You can have it on for as long as you like. Usually you don't have to drop it even that much.