DIY Laser Torch - 323mA! - Wow!

[LarryQ]

I've been running mine for quite a while now....@ 325Ma

No problems at all.....

Given the MASS of Alum I'm using, it really is whicking the heat away quite nicely!!

Right not it's using a GB diode but it's awaiting the infamous Phasor diode...if that GB ever comes true.

Larry

 

[jayrob]

I've been running mine for quite a while now....@ 325Ma

No problems at all.....

Given the MASS of Alum I'm using, it really is whicking the heat away quite nicely!!

Right not it's using a GB diode but it's awaiting the infamous Phasor diode...if that GB ever comes true.

Larry

Hi Larry, I think that your Q-beam design (as I call it) is very stable so far...I have 3 now with no problems. It may also be of interest to some, to know that I have a box style with a similar heatsink set up running at 351.6 mA as a test for the AixiZ diode which is supposed to be rated at 350mW pulsed and 200mW CW. I don't have a way of measuring output power but if this diode is similar to the Phazor diodes that DDL tested, then it should be putting out around 200mW at this current correct? Anyway, it burns even hotter! (according to the old 'arm test' - OUCH!) Here's a picture alongside a smaller one I am making for the Phazor diode. For the smaller one, I plan on mounting a 3/4" heatsink (but longer) completely inside the box, with the module sitting flush with the outside of the box. (notice the LM317 is heatsinked as well, and isolated)...
Jay

 

[toked323]

hey jayrob if you want to sell any of those heatsinks letme know as i cant make my own anymore ill buy em from you

 

[jayrob]

hey jayrob if you want to sell any of those heatsinks letme know as i cant make my own anymore ill buy em from you

Man I just gave away the two extra ones that I made last night...I havn't really thought about selling them because it probably wouldn't be something that would make sense time wise. I mean, it takes about 30 minutes or more to make one. (I'm no pro machinist) If you want one bad enough, PM me with an offer. It's just that, as you can imagine, I wouldn't have the time to make a lot of these. Here is a picture with exact dimensions if it will be of any help to those who may be interested in making one, or having one machined...
Jay

 

[Benm]

Here's a picture alongside a smaller one I am making for the Phazor diode. For the smaller one, I plan on mounting a 3/4" heatsink (but longer) completely inside the box, with the module sitting flush with the outside of the box. (notice the LM317 is heatsinked as well, and isolated)...

Perhaps a few pointers here: Using a heatsink for your diode -inside- the case is useless. It'll just radiate/convect heat into the case, that has to be redirected by the case to ambient. Just mounting it to the case with good thermal contact has the same effect. A heatsink on the outside of the case does improve heat transfer to ambient.

Same thing for cooling the LM317: you could do that by just bolting it to the case using a little mica insulating plate and nylon bolt... those are commonly available from electronics stores.

 

[jayrob]

Hi Benm, thanks for those pointers...if the face of the aluminum heatsink that I plan on pressing the module into was glued to the inside of the box using Arctic silver epoxy, wouldn't it be transferring the heat to the box as well? I very much appreciate your input...
Jay

 

[DoughDTD]

nice work man, im in the process of building a heatsink myself for those MXDL flashlights.  Mine is gonna be a bit larger though, with some fins.  It will be cooling the diode which is running at about the same mA. Here is a sketch of what itll look like, im about 80% finished machining it, so ill show some shots when i finally get some time to finish it up.

*EDIT* This will be visible from the outside of the flashlight housing, meaning that front black piece that normally hides the module has been cut much smaller, and this whole heatsink will be sticking out of the end of that shorter piece. It sounds weird, but ill show some pics soon :

Thanks for this thread ,I was a bit nervous about trying to run the diode on such a high current, but you gave me a little bit of confidence that itll work...i hope! haha

-Dough

 

[SenKat]

Dough - that looks an awfully lot like a Nitro engine radiator....Check out Stevetexas' posts in the experiments section - he put a couple on various Dorcy torches....

 

[Benm]

Hi Benm, thanks for those pointers...if the face of the aluminum heatsink that I plan on pressing the module into was glued to the inside of the box using Arctic silver epoxy, wouldn't it be transferring the heat to the box as well?

It would transfer the heat to the casing fine in that case. The issue is that there is no benefit in using a heatsink with fins/ridges/etc, since it's just a connection between LD holder and case. This could just be a block of metal with a hole in it that fits your LD casing. This is equivalent in function to the cylinder in your picture, though it doesn't need to be as long as it is now.

If you go for the block-with-a-hole approach, you could make it relatively thin (5 mm or so), but large enough so you get bolt it to the case with just a bit of thermal compound in between. Such connections transer heat way better than a layer of glue.

 

[DoughDTD]

greg, thats where i got the main ideas for the design, was from RC cars. My buddy is big into RC car racing and he showed me the heatsink design on his car, so i went from there and adapted it to fit the flashlight and encase the circuit and module. It was all machined from a solid block of alumiminum though, and from start to finish should take approximately 3-4 hours of machineing. (much shorter if i had a CNC lathe, but i have to do it all manualy)

 

[jayrob]

If you go for the block-with-a-hole approach, you could make it relatively thin (5 mm or so), but large enough so you get bolt it to the case with just a bit of thermal compound in between. Such connections transer heat way better than a layer of glue.

Benm, thanks for that excellent information. I do want to build it in such a way to wick the heat as best as possible, but at the same time have the module mounted flush with the outside of the box...
Jay

Thanks for this thread ,I was a bit nervous about trying to run the diode on such a high current, but you gave me a little bit of confidence that itll work...i hope! haha

-Dough

Dough,
Props to LarryQ! (and of course, DDL) Well, at least that's who I learned this heatsink/3.9 ohm configuration from....I only changed the design of the heatsink. But this mod is a great fit for the MXDL! I had to share Larry's idea with everybody! Looking forward to some pictures of your awesome heatsink...
Jay

 

[Benm]

I do want to build it in such a way to wick the heat as best as possible, but at the same time have the module mounted flush with the outside of the box...

Mounting the conduction block/disk inside is fine then... it can be flush or even slightly recessed (to prevent scratches etc) from the outside if you want to.

 

[LarryQ]

Remember that the heatsink is just prolonging the enevitable!

You can't run 100% duty cycle at these current levels!

The Heatsink just buys you more "On" time..

A TEC (Active Cooling) would be the best here..but I was after a flashlight mod...something Powerful and Handy!

Hey Jay....

Give some thought to spinning up a spacer so that the MXDL can use 3 CR-123 cells.....

Something to screw in between the end cap and the main body of the flashlight that gives enough added length for that extra cell!!!

9V would be a hell of a lot better than 6V at this current level!!!!

hehehehehehehehehehe

Baaaaaccckkk to the LAAABOOORAATTTTORRRRYYYYYY...........Muuuhuuuhhaahahahahah


Larry

 

[jayrob]

9V would be a hell of a lot better than 6V at this current level!!!!

hehehehehehehehehehe

Baaaaaccckkk to the LAAABOOORAATTTTORRRRYYYYYY...........Muuuhuuuhhaahahahahah


Larry

Yeah! That sounds like a cool project Larry...Is it ok to run 9 volts? I mean, I know the current will not be affected, but would the voltage to the LD be too much? If 9 volts is ok, then two 3.6 rechargables would be ok as well...correct?
Jay

 

[a_pyro_is]

Jay, check my post in the driver thread

 

[jayrob]

Jay, check my post in the driver thread

Pyro, I have wanted to use 3.6 volt rechargeables but wasn't sure if it would be ok for the voltage to the LD in DDL's circuit. I have tested these batteries in this circuit but not with the LD connected. Using 3.0 batts, I got about a 5.6 volt reading and using the 3.6 batts, I got over 7 volts so I never tried the 3.6 with the LD connected. It sounds like you have been using the 3.6 batts as well as three 3.0 volt batts in a 9 volt set up? And, never does the circuit allow the volts to the LD to go above 3 volts? That's good information to know. Please confirm...
Thanks,
Jay