Attempted Labby (PICS)

[Gryphon]

The title says "attempted" because the resultant laser is far from i deal but i
thought i would go ahead and share it with you guys. The heasink is a from
a CRT monitor i tore apart, it orginally had mofset or some kind of transitor
mounted to it, it made a great place to attach the LM317 i used as the
lasers driver (set to 1A). The laser module is mounted to the same heatsink,
i took advantage of the fact the diodes die is "floating." The fan on top is
from the projector and it can move a lot of air.

*careful with these fans, they can really rip! I had one hooked up to my PSU
at 12V and it was pushing enough air that when i put it on my desk it was
actually strong enough to lift itself up a mm or 2 and move across the table
on its own. When i went to grab it, my pinky finger touched to exposed
blades and was promptly scapled! By the time i made it to the bathroom
(first door on the right) i already had blood down my finger across my palm
and headed for my wrist and forearm, these fans don't mess around!

That said, you'll notice a grill on the top of the fan i made out of soldered
together paper clips to keep my fingers out :crackup:

 

[andy_con]

looks good but very poor heat sinking

 

[Rafa]

LOL@ fan story!

Cool, but, as said, get a serious HS.

 

[JLSE]

LOL, those fans are vicious, but do the job where air flow is needed.
I hooked up the cluster of three that sit behind the array, held them
to the table and powered up. I placed a full 500ml water bottle laying
down, and the three fans quickly rolled it out of the way. By far the
strongest AND smallest fans I have personally seen up close.

I had also did some temp. measurements of the array in the casio, the
three fans are able to keep the array's temp in the area of 30c. By resting
the array on top of the projector, the temp quickly shot up to 70c in the
matter of a minute or two. As far as im concerned, they do their job
really well. Im curious to what the CFM rating is for these, but cannot find
that info anywhere.

If I was to make any suggestions, I would try to recede the LD module
into the heatsink a little more. This may not be necessary though...
Does the LD stay cool when running? and how is it mounted? Is it
threaded into the hole or is it bonded in?

As long as there is a good tight fit, the rear threads of the module
with some good paste or thermal epoxy should be able to draw off
the heat. Let it run for 5-6mins, if the module is cool to the touch
than i'd say its fine and the HS is doing its job...

Other than that, nice work :beer:

The title says "attempted" because the resultant laser is far from i deal but i
thought i would go ahead and share it with you guys. The heasink is a from
a CRT monitor i tore apart, it orginally had mofset or some kind of transitor
mounted to it, it made a great place to attach the LM317 i used as the
lasers driver (set to 1A). The laser module is mounted to the same heatsink,
i took advantage of the fact the diodes die is "floating." The fan on top is
from the projector and it can move a lot of air.

*careful with these fans, they can really rip! I had one hooked up to my PSU
at 12V and it was pushing enough air that when i put it on my desk it was
actually strong enough to lift itself up a mm or 2 and move across the table
on its own. When i went to grab it, my pinky finger touched to exposed
blades and was promptly scapled! By the time i made it to the bathroom
(first door on the right) i already had blood down my finger across my palm
and headed for my wrist and forearm, these fans don't mess around!

That said, you'll notice a grill on the top of the fan i made out of soldered
together paper clips to keep my fingers out :crackup:

 

[Benm]

With forced airflow, i think that heatsink should be fine. Its important to get a really good thermal connection between the aixiz module and the heatsink though.

Also, i'd recommend not mouting the LM317 to the same heatsink: Those voltage regulators are designed to be able to run very hot. Mounting them on the same heatsink just heats the diode more. Its better to put them on their own (little) heatsink, and run hot, but out of the way of the laser diode.

 

[JLSE]

With forced airflow, i think that heatsink should be fine. Its important to get a really good thermal connection between the aixiz module and the heatsink though.

Also, i'd recommend not mouting the LM317 to the same heatsink: Those voltage regulators are designed to be able to run very hot. Mounting them on the same heatsink just heats the diode more. Its better to put them on their own (little) heatsink, and run hot, but out of the way of the laser diode.

I mounted the circuit inside my CNI labby, with the LD running close to
1W and 12v into the LMXXX, all the heat is dissipated quite well.

I am not using a fan with mine... The fan he has on this laser should be
more than adequate to dump all that heat.

The stock casio HS for the array is just under 7oz, and in combination
with the three fans, keeps the 24W at bay. Keeping in mind that the
casio HS has more surface area..


I think if anything, Gryphon has to do some temp testing with his LD
running at full. As long as it maintains 30c (Think 29c is the magic # :thinking
it should be fine.

Mounting the IC on the same block falls into the 'two birds with 1 stone'
category... never a bad thing.

 

[FireMyLaser]

Funny how you already made a labby as I just made one of my own! So I just post it here if you don't mind. Labbies are fun!

I need a powerful laser that don't use batteries so that I can use it for as long as I want for various things, as a tool. I used only stuff I had laying around, the case in an old battery charger (it was perfect for the job!) and pretty much chucked it together in a couple of hours.

I like the "easy focus" on this thing, it's a piece of a pen.

Theres a on/off switch, a potentiometer for adjusting the output, and an override switch to instantly jump to full power. It is really useful when setting something up, to have very low power at first and switch to full when everything is in place. The pot-knob is also a piece of a pen.

I didn't have any rubber feet, but esd-foam works fine too.

I don't have a grill, maybe I should solder one as well, eh?
The fan is a bit noisy, I might add a potentiometer for it later on when I use it for lower powers.

Just a common lm317 driver, with 1.45A maximum.

The laser heatsink has been reused many times in my projects.

Guts.

The diode is an oldie, the window got damaged long ago, but it works just fine removed.

Blue.

 

[Benm]

Mounting the IC on the same block falls into the 'two birds with 1 stone'
category... never a bad thing.

I don't know about that.. you could use passive cooling for the laser diode with a heatsink no larger than the displayed hs/fan combo, with the driver toasting away its heat on a seperate heatsink.

Then again, i'm not a fan of fans - i prefer things to be all solid state if possible. Obviously you can reach a point where its no longer feasible, but with these 445s it is for a labby.

 

[JLSE]

I don't know about that.. you could use passive cooling for the laser diode with a heatsink no larger than the displayed hs/fan combo, with the driver toasting away its heat on a seperate heatsink.

Then again, i'm not a fan of fans - i prefer things to be all solid state if possible. Obviously you can reach a point where its no longer feasible, but with these 445s it is for a labby.

Agreed, and fans wont make for accurate stability nearly as well.
Not a fan of the noise either. I have tinnitus and even low noise as long
as its ambient makes my ears ring...

I have too many fans going around me at any given time.
And im not talking about TJ :na:

 

[Toke]

It looks nice, I wondered about the LM317's output to case.
Blueray and 445nm have isolated case, but what about your PSU?
Doesn't it have the 5V and 12V zero connected to case?

That would be a problem if the feet of your labby touch anything but painted surface of the PSU, perhaps some foam padding under the feet would be an idea.

 

[JLSE]

It looks nice, I wondered about the LM317's output to case.
Blueray and 445nm have isolated case, but what about your PSU?
Doesn't it have the 5V and 12V zero connected to case?

That would be a problem if the feet of your labby touch anything but painted surface of the PSU, perhaps some foam padding under the feet would be an idea.

In my retro fitted CNI labby, the IC was fitted with a nylon collar for the
screw, and a thermal pad under it. This keeps the adj./ r-set pin of the LMXXX
isolated from the body, and in turn, isolates the head.

Touching the r-set with -neg will cause a dead short of the PSU / IC, and +pos
will send all availible current and voltage to the LD....p00f

 

[Gryphon]

Tommorow i'll do some temp tests, i have only run it for 5~8min bursts and the fan seems to keep the sink from getting any hot than "warm"

The module is threaded into the sink with a little arctic silver 5 for good measure.

 

[Gryphon]

UPDATE: I just got done doing a 30min run while taking some temp
readings off the side of the module where it meets the sink.

Start: 78.2
1Min: 92.8
2Min: 93.3
3Min: 94.5
4Min: 94.6
5Min: 95.1
6Min: 95.3
7Min: 95.6
8Min: 96.3
9Min: 96.4
10Min: 97.3
15Min: 97.4
20Min: 98.1
25Min: 98.3
30Min: 98.9

All temps are in F, and the starting temp at the top is what the laser was at after sitting in
my room all moring while i was at class, so no pre-cooling or pre-heating from prior running.

 

[JLSE]

UPDATE: I just got done doing a 30min run while taking some temp
readings off the side of the module where it meets the sink.

Start: 78.2
1Min: 92.8
2Min: 93.3
3Min: 94.5
4Min: 94.6
5Min: 95.1
6Min: 95.3
7Min: 95.6
8Min: 96.3
9Min: 96.4
10Min: 97.3
15Min: 97.4
20Min: 98.1
25Min: 98.3
30Min: 98.9

All temps are in F, and the starting temp at the top is what the laser was at after sitting in
my room all moring while i was at class, so no pre-cooling or pre-heating from prior running.

Did you measure the heatsink as a whole or the LD mount?

Those numbers are a bit on the warm side, but nothing drastic.
If you measured the heatsink only, it would be interesting to
see the comparison of the LD mount and heatsink side by side.

A single measurement of each would suffice, with a good long
warm up time prior to the readings.

Like Benm said, the LM317 is going to contribute a fair amount
of heat. So if you want to get those numbers down a bit, you may
want to try and remove the LM317 from the HS and see what
happens.

By the looks of things, it is slowly warming up which will take
away from your output over duration of runtime.
Removing the IC from the HS should give you better lower temps
and a more stable output.



If they are near identical, it would say to me that the transfer of
heat is well within a safe boudary.

In the projector, these LD's hover around the 30c mark in econo-mode.
What I also found odd, is that the 'thermal protection' circuit in the Casio
is rated for a 100c shutdown..

Wonder if the indium would melt off the die at this temp? You could
literally boil water on the casio's array before it would shut down :undecided:

So its been proven that these LD's can take a much greater amount of heat,
the question remain, at higher temps, what physical effect does it have on them.

 

[csshih]

I gotta comment that your computer PSU conversion looks really nice!
last time I tried to make one that neat, it literally blew up.

now oddly enough, my current PSU isn't working anymore..

 

[Gryphon]

I measured the temps with an ir thermometer off the side of the module, thats as close as i could get to the diode, short of pointing straight down the in the module. I also took the temp of the LM317 at the same time i took the temp of the laser, but i never did write any of the temps down since it was always cooler than the laser module. The fan really does move a ridiculous amount of air across the heatsink, which is probably why its staying at a fairly reasonable temp.

Thanks csshih, i just finished it up a couple days ago. What happened to yours that made it pop