Underdriven 9mm 445nm for Continuous Duty Cycle

[LaZeRz]

I didn't notice any difference, it might have been there, but it wasn't significant enough to be noticeable.

That was running off a battery with a shot protection circuit which severely limited the current and made it look almost LED. It was set in a hotlight with similar heat sinking to a c6. For the short time I ran it, It didn't warm up at all. Not sure about running it continuous though.

 

[jander6442]

Well I'm starting a build today w/9mm diode in one of my HF mini mags... of course it is going to have a pretty sweet sized heat sink compared to the C6 for sure, but there are some other challenges mostly input voltages, but I am looking at a 1.8A range.

 

[sandtiger08]

Well I'm starting a build today w/9mm diode in one of my HF mini mags... of course it is going to have a pretty sweet sized heat sink compared to the C6 for sure, but there are some other challenges mostly input voltages, but I am looking at a 1.8A range.

Do you have a pic available of your host/heatsink? @ 1.8A I think you will get around 2.1w-2.4w depending on your lens. Grrr I would love to get that with passive heatsinking, in a portable host, but I know it's impossible with the diodes we have.

Fans have been suggested to me by a few members. I'm looking into a copper core, aluminum wrapped, finned heatsink. Working out how to wire in micro fan(s) and have them run off of the driver, and have them flush set in the heat sink. The ones I am looking at have a 60mA draw. Just ideas atm, still getting parts together for testing. I have some 25mmx25mm fans that I can use to test and if they work well maybe get the micro ones. Wondering if the fan will cause fluctuation in the diodes power supply enough to be an issue. Maybe run a second chepo ebay driver just to run a couple of tiny fans. Drawing board phase is the most fun of a project. Imagination without limitation. It had even crossed my mind to find a way to mount a mini version of the H50 watercooling setup to the heatsink, and still have is portable. I couldn't figure out how to make it smaller then one of the bigger Mag builds :/

 

[jander6442]

Here you go
http://laserpointerforums.com/f51/assembly-hf-mini-mag-4x-405nm-pic-heavy-83558.html
http://laserpointerforums.com/f42/tec-mag-445nm-firefarter-77157.html
http://laserpointerforums.com/f50/loc-active-cooled-handheld-3-phases-55914.html

 

[ApexProxy]

Basically what Blord said. You will not get infinite duty cycles without active cooling. The thing is with the designs we use in our lasers we surround the diode in a chunk of metal that acts as a heat buffer gathering the excess heat as the laser runs. At some point the heatsink will start to gather enough energy so that it will start rising in temperature past optimal levels. This is basically the same reason your computer has a fan on its heatsink.

IMO, C6s are pretty small for 9mm diodes if you desire to run them over about 1.8A. I would suggest getting a larger host with a copper heatsink such as an L2(FlaminPyro makes some of the best heatsinks I have seen) and getting a good buck driver such as an X-Drive that will produce very little heat and is quite efficient. If you run the 9mm at 1.6-1.8A its life span will be very long and your duty cycles would probably between 2 and 3 minutes. If you want even longer duty cycles and runtimes you could look into using a Maglight from jayrob though it will be more expensive.

 

[n2stuff]

If you want a BIG custom heatsink PM mrcrouse..... http://laserpointerforums.com/f39/m...illing-turning-polishing-anodizing-78525.html

 

[ApexProxy]

I'm personally more of a fan of FlaminPyro's work. Either way if the ultimate goal is long duty cycle you should target copper and you can attain long runtimes from smaller hosts.

 

[n2stuff]

I'm personally more of a fan of FlaminPyro's work. Either way if the ultimate goal is long duty cycle you should target copper and you can attain long runtimes from smaller hosts.

Yup Jeff does great work in copper. But I don't think he does them with finns. I believe a finned heatsink will dissipate heat much better than solid one regardless of material.

 

[ApexProxy]

It depends on the design. Most lasers have the heatsink internal to the host therefor fins wouldn't make a difference. If the heatsink expends far enough past the host then fins would be effective if they are deep enough. I'm not much of a fan of that style though...

 

[LaZeRz]

There would be absolutely no point of a finned heat sink if it going to be enclosed. In fact, it would be worse than a solid one. If the heat sink will be protruding out of the front of the host, it would help to have fins only where the heatsink is exposed.