DIY:My 1st build, a 1.5W labby for ~60$

[anselm]

So a few weeks ago I bought my first A130 diode from member
kingdingeling. Nice transaction. :wave:

Then I ordered me an O-like housing + 445nm coated lens.

After practicing soldering wires to various optical drive diodes,
I finally got confident enough to solder a pair of wire (from an USB cord)
to that blue little marvel.

Hooked it up to my makeshift lm317 driver and was immediately amazed
by the colour and power. Thank you, Nichia! :bowdown:

So next up I had to find me a host to install that blue and powerful module into.

I love DIY, so buying one of the many great hosts offered by LPF members
was out of the question for me.
I don't consider them too expensive or anything, but I thought for my
1st build I'd rather make as much as I can myself, so I can learn as
much as possible along the way.

OK, I'm sure this has been done before, since it strikes me as so obvious...
I made a "labby" out of a desktop PC power supply unit.
These things come with two useful things to start with:
-a fan,
-on-off switch.

I removed the innards of the PSU, along the way salvaging two pieces of
heatsink for later use.

Drilled and filed a hole for the module itself, an another one for the batteries.

Battery tube, made from rolled up cardboard, holds 2x18650 giving just the
right voltage for a 445nm + lm317.

Then I wired up the driver for several power settings.

The standard on-off button keeps it's function.
Default power level is determined by a 5Ohm resistor yielding 250ma current.
The 3prong power plug now serves as place to put a jumper, selecting either
around 800ma, or instead bypassing the lm317 resistors altogether,
making the lm317 effectively push its rated limit of 1.5Amperes.

The diode takes it happily, so I feel very safe tinkering with the lm317,
knowing that it will never exceed those 1.5Amps
EDIT:
Fresh batteries off the charger made for a current of 1.95A! So don't rely on the lm317s rating!

I also installed a "burn" trigger button which momentarily gives the diode its full power, regardless of the jumpered power setting.
I'm really having a lot of fun soldering around with various resistors, connecting
things here and there and see what happens.
And inside the box there's plenty of space

Anyways, I'm really happy with the intermediate results!
It's such a neat little tinkering box.

I advise anyone looking for a cheap and rewarding project to build one.

I find it to be so versatile, it's a labby, so I can set it somewhere
without fear of it rolling off.
Yet it is small enough to be relatively portable, being battery powered.

Defocused onto a mirrorball it makes for nice ambience.

Properly focused and on full power, it'll light a match instantly and
poke through the black plastic inlay from a CD jewel case in one second.

On new years eve, it lit fireworks and earned curious looks from people
all around me.

I could go on and on but I don't want to bore you to death.

 

[anselm]

Pictures added!
It's working fine for now, but I want more!
So I'd love your comments on this. What do you think?
This thing needs bells and whistles!
I'm thinking:
-painting it black
-warning label from twhite's label-generator
-more switches
-status leds
-wiring up that fan so it actually works
....
...

power demo:


I'm a very happy camper now!:wave:
This is what this hobby really boils down to, for me at least.

 

[Elektrotechniker]

Nice diy build there. However, why do I think that the diode is not cooled enough? Seeing that bare housing for the diode and no aluminum or copper around it seems "poor". No offense included, i'm just wondering

 

[anselm]

Maybe you missed the finned aluminum plate sandwiched onto the PSU casing,
against which the diode holding part of the module is screwed tightly.
The diode itself is smeared in thermal grease to make good contact to the module.

But yeah, i've been meaning to run it at full power for an hour, see how much it warms up.

EDIT: after running at full power for 40 minutes, the module and aluminum plate are only warm to the touch
At the end the batteries were at 3.7V under no load, and they were only pushing 1.2A...
Popped in some fresh ones off the charger, and WOW now the current draw at the
batteries was 1.95A! Yikes!
Looks like the ol' lm317 DOES allow for more than 1.5A... hmmmmmmm
After a few seconds of this, the light went dim and dimmer....
Shocked, I turn it off immediately.

Happily, the light went back on a lower power setting of 0.85A like nothing happened.
Yet another testimony to the toughness of these amazing diodes.

 

[Cyparagon]

It needs an adjust resistor no matter what current you run it at. You're lucky you didn't blow something up by omitting it. 0.8Ω should give you 1.5A.

It is rated for 1.5A. That doesn't mean it can't do more, it just means you're pushing your luck if you raise it higher.

 

[Aaron]

Instead of bypassing the resistors altogether, I think you should have another jumper wih a 1 ohm to get 1.25 Amps.

 

[Leodahsan]

it is rated at 1.5A because it can only fully dissipate heat (heatsinked with copper/silver/diamond or not heatsinked at all) at 1.5A. beyond that it will slowly overheat, and eventually shutdown

 

[Cyparagon]

But 1.5A at 3V drop is less heat than 0.5A at 10V drop. The junction temp is more related to heat sinking than it is to current. If it were purely heat related, you'd think they would rate it in watts (like diodes, resistors etc.)

 

[hakzaw1]

Love those PS boxes- lots of uses and if painted black most dont know where you got it. I have three labbies like yours in the works and this thread will be very helpful so TY to all who have added the great help.

I may even try to make a very simple TTL GB projector in one. and a R+G to make a yellow labby-a G+B to make a teal labby and a R +Br to make a magenta labby.

A good and cheap way to monitor your temps is an IR thermometer.its fairly accurate & selective- aiming it at your drivers and diodes can tll you a lot.

I never pass up a tower sitting by a dumpster - some thrift shops/ computer repair shops etc give them away if not sellable. just dont forget to re-e-cycle your leftovers--hakzaw

 

[anselm]

I never pass up a tower sitting by a dumpster

Dumpster diving rules very much, I've found so much you wouldn't believe.

...and if painted black...

Did you mean like this?

Muuuaaahhahahaahaha

Next up:
wiring some more sensibly spread apart power settings, using
sneaky secret hidden magnetic REED switches. I just got a lot of 40 off the bay.
Anyone need some 1A reed switches?

 

[weeba2kv]

lol DIE! stupid slow old floppy

 

[JaiNobeZ]

I'm no expert, never having messed with 445s, but my feeling is you should stick the module in something like this: Heat Sink for 12mm laser modules

Idk... doesn't look like it's making such great thermal contact to the outside. Sorry if i've misunderstood something.

Otherwise, i love it!! How is the power adjusted?

 

[anselm]

There is a chunk of aluminium sandwiched between the two halves of the O-like module,
about right where the diode sits. Thermal grease makes for a good contact.
The heatsink warms up in unison with the module, and after running about 30 min on
1200mA, it only gets comfortably warm to the touch, and doesn't go much from there.

I am considering upgrading to a bigger chunk of metal though.
On the left is one just like the one it's using right now, on the right is the upgrade I'm considering.

Now that its been rewired, power is adjusted by "barbie's circuit breaker panel", as my GF called it.
Here's a thread about it, scroll all the way down.
This is how it looks now:

Oh yeah, the "burn trigger" now has a 0.4Ohm instead of just a wire, just to be a little safer.

 

[JaiNobeZ]

The circuit breaker power adjuster looks small and fiddly.

This looks really fun though. Soon as i have the confidence to solder to diodes, there is a high chance i'll do this. Only i'll call mine a "box of tricks" instead of a "tinkerbox".

 

[vk2fro]

quite funny - a watt of laser labby in an old psu for a computer, burning thru a floppy - made me grin.

oh, and you mean you actually had a floppy hanging around to sacrifice?

nice build btw

 

[JaiNobeZ]

My room used to be the room the computer (back when we only had one) was kept in. In the days when they still had floppy disk drives. There's a HUUUGE pile of them on the shelf.

Suggestions for fun stuff to do with them much appreciated.