Ambitious burner project idea & heatsink question

The other day I noticed that the head of an Aixiz module (or in my case, the DX cheapo knockoff (http://www.dealextreme.com/details.dx/sku.5914)) fits nicely into this "Super Mini Vintage Oil Lighter" (http://www.dealextreme.com/details.dx/sku.3734) with enough room to clear the lid.

I immediately envisioned a tiny keychain burner of some sort... Figuring I could fit 3 or 4 cr1025 3v lithium button cells in there, and if I could point-to-point solder some smt components into a tiny driver, I should be able to do it...

A couple things have occurred to me as potential problems... one being how the hell am I going to mount a button in this thing... and secondly, I have no real experience building burning lasers before so I don't know if the head of the module will provide enough heatsinking... I'll probably have to insulate it from the case since I'm thinking of a screw-in-to-turn-on type of switch... I'm obviously not going to need continuous duty from this thing, probably going to be using it for a max of 20 seconds at a time. Can anyone tell me if that will be enough to prevent catastrophic thermal failure?


Any input on whether I'm crazy or not?

Re: Ambitious burner project idea & heatsink quest

dont see why it wouldent work jsut got ot get a good driver so you dont blow te diode

Re: Ambitious burner project idea & heatsink quest

yeah I don't see any problems.

The heat would be a BIT of a problem, but just don't keep it on too long. The thing is small enough, so you can feel when it gets too hot and when you need to shut it off.

Re: Ambitious burner project idea & heatsink quest

i think it is enough dissipation for a 5mw..

go for it!!

post pics then

Re: Ambitious burner project idea & heatsink quest

nikokapo said:

i think it is enough dissipation for a 5mw..

go for it!!

post pics then

Click to expand...

umm, well.. I'm planning on using a diode from a random 18x dvd burner, so I'm guessing the power might be just a bit over 5mw ... still think it's enough heatsinking?

I'm definitely going to try this, it's just too tiny and cool not to... the all-chrome-plated-steel-construction is pretty sexy imo.
I'll be waiting on another module from DX to arrive (mine currently has a BR in it, eagerly awaiting bluefusion's driver) before I can try anything, but I'll be sure to post pics when I do!

also, unrelated, but I just got 4 (count em, FOUR) as-is 18x dvd burners for $10 on ebay! Awesome, no?
Let's just hope they're all mechanical problems, not burnt out diodes or something.

Re: Ambitious burner project idea & heatsink quest

It seems like a really tiny case, but if you are able to fit a driver and some batterties that can deliver the current required (check!), it should work out.

Thermally it will never be something suitable for continous use, but using it as a 'pointer' should be okay. If you have the space, you could drill a small hole and mount a tiny switch behind it.

Re: Ambitious burner project idea & heatsink quest

Sorry to burst your bubble...

You will never ever get enough current from button cells.

Renata CR1025 datasheet claims maximum discharge current of 0,4 mA and a capacity of 30 mAh

http://www.renata.com/pdf/3vlithium/DBCR1025.03.pdf

And it won't be much better for any other types of of button cells I'm afraid.

Sorry,
Steve

Re: Ambitious burner project idea & heatsink quest

Maxpowa said:

Sorry to burst your bubble...

You will never ever get enough current from button cells.

Renata CR1025 datasheet claims maximum discharge current of 0,4 mA and a capacity of 30 mAh

http://www.renata.com/pdf/3vlithium/DBCR1025.03.pdf

And it won't be much better for any other types of of button cells I'm afraid.

Sorry,
Steve

Click to expand...

I have to agree here, and I learned from experience. I couldn't get much current out of any buttons or small automotive batteries, so i opted for a PC battery that is very small and rated 7.5 volts. It still had low current, and even witha DDL circuit configured for 240 mA, I was only able to get 140-160 mA out of it(but able to BURN). And had to use it less than 20-30 seconds. Seach for my post called " So i wanted a smaller burner" to see the size I made mine. I could have shaved off another 3/4 inch if i wasn't lazy and wanted to use a tactical momentary switch (that I have).

Re: Ambitious burner project idea & heatsink quest

:'(

hmm... what if I were to run four of them in parallel and make a tiny boost circuit to bring it up to the right voltage?

desslok: what type of PC battery did you use? what are its dimensions?

Re: Ambitious burner project idea & heatsink quest

pseudolobster said:

:'(

hmm... what if I were to run four of them in parallel and make a tiny boost circuit to bring it up to the right voltage?

desslok: what type of PC battery did you use? what are its dimensions?

Click to expand...

That would be just as bad as the boost circuit would require more current to bring the voltage up as apposed to using the batteries in series...you can't magically make more voltage appear, the power has to come from somewhere. Although it would be nice if we could.

Re: Ambitious burner project idea & heatsink quest

pseudolobster said:

:'(

hmm... what if I were to run four of them in parallel and make a tiny boost circuit to bring it up to the right voltage?

desslok: what type of PC battery did you use? what are its dimensions?

Click to expand...

This is basically the same battery I got. Again, i wasn't concerned with cost, or being able to recharge it, or even it's run time. I simply wanted the smallest burner possible. And my burner altogether is about the size of 2x cr123s and will almost fit into my MXDL's battery compartment. I have ran it for 15-30 seconds at a time here and there for a couple weeks. I wouldn't expect it to last very long if I used it much more.


http://www.smallbattery.company.org.uk/sbc_a175.htm

Re: Ambitious burner project idea & heatsink quest

couldnt u just wire a higher capacity battery (maybe u can wire it to a battery case so u can replace them easily) and then attach it right next to the laser?

it wouldnt look too cool, but it'd give u the power u need.