First Build / Experimenting - Suggestions on which direction to head next?

So ... I bought a 400mW 405nM on o-like on the 31st. Sitting around looking at DIY threads I said "Ehh...I can try that".

Here are a couple diodes I harvested from a dvd burner.

Any tips, suggestions, input on where to go next with this?

I've been looking at this thread considering working on my own driver, Assuming this type of driver will be okay for these diodes?

Then moving on to a host and module setup from there once I get the diodes running okay?

Also as I understand it these are both 635nm? an IR would only have two leads?

Also what kind of output max can I expect from something like this?

These are the diodes (yes one of them got a bit scuffed up, don't think that should cause any issues ... right? lol):



This is the burner they came from:



**********************************************************EDIT********************************************************************************************************

Now the more I look at it the more I'm starting to think one of the diodes has a cracked glass. Is there a definitive way to tell besides just looking? I'm really not 100% sure what it's supposed to look like? Someone lie and tell me that's not a crack on the right most diode???

Looks a bit cracked, but it's hard to see on those pictures.
How fast was that DVD writer? 12X, 16X, 22X....?
Maybe those aren't red diodes at all but IR diodes.
Even if they were red, they would be 660nm rather than 635nm.

To test wether the diodes are visible wavelength and working, you can
put your digital multimeter in "diode test mode" and try touching any two
pins with the probes in one direction and the other (swap probes/pins).
when you found the right pins and the correct +/- orientation, AND the diode
is indeed a red one, you should be able to see a faint red light inside the diode.
Mind you, it's not lasing at all like this, but it DOES produce a tiny amount of light.

16x

That's true, didn't think about the digital multimeter :thinking:

Well, They're both red diodes, one's a bit brighter than the other. Here's what I've got going on so far, any tips on getting a bit more power out of them? I don't have access to my multimeter at the moment =|

This is a quickly-made version of a drive that I "copied" from the thread I listed earlier. The diodes start to fade after about 30seconds of run, not sure if this is battery dying or diode dying?

even at low power, I wouldn't recommend running them very long without at least modules.
ESD is another consideration, make sure you are grounded.
I have put together a couple of lasers in the winter, first wired my leg to the steel welding bench to press the diodes, then wired to the (copper) plumbing when I was soldering connections and assembling each of them.
Don't know why they would be fading though unless you are running them too hard.

A module for over heating purposes?

As far as ESD goes, would just grounding out the third leg of the pot do it?

Really shouldn't be running them too hard, I'm using this guide / driver (third pic down) and only about 6v input power. Again I don't have access to my multimeter so i cant be sure about the output power.

Those are not both red diodes. The smaller one is an IR diode but it will have a faint red glow. IR is pretty dangerous so I wouldn't even mess with that one unless you want to practice soldering. Whatever you do, don't look into the IR diode while powered up.

The LCC is the red diode. You can also tell from the tint on the diode window. On IR diodes, the coating will be a very pale, light blue. On red diodes, the coating is a very deep blue. Lots of IR diodes don't even have windows.

What are you using for a power supply?

Hmm well that's good to know lol, I guess I just figured that an IR diode you wouldn't see anything. I haven't really looked into IR much.

I'm using 4 AAA's and have tried a 9v.

That's kinda weird that the diode starts fading after 30sec with that power supply. I would guess that 4XAAA batteries are not enough capacity for it. Are they brand new?

You could try a bench PSU or batteries with a larger capacity.

One of those 9V rectangle batteries definitely doesn't have enough capacity.

I thought about a bench PSU at around 12v? but the op's "schematic" said 7.2v input so I was a bit nervous to even try the 9v, this is the last unused dvd burner i have on hand! lol but i'll try the psu if you think that'd be okay?


working on pulling the ir off right now.

No problem feeding 12V or even 16v, 18v to the lm317.
It WILL heat up though, dissipating the unneeded extra voltage.
So heatsink the lm317.

perfect! good to know

Sorry I didn't respond right away Maros, my daughter came home puking. (fun!!!). :wtf:

But thanks for stepping up and answering his question Anselm. :thanks: :beer:

No worries kev, I have a 4yr old ... I know how it is! I'm just excited to get this much input from people at all lol.

Now that I've cut my thumb up a bit, are you all ready for this awesome heatsink??

That's a good start, but it doesn't look very massive (it should be),
neither does it seem to make very good contact (warped) with the IC.

Just run it and check if the soda can warms up the same as the IC.
Then at least it IS sinking properly.
Ideally, it should be at the same temp as the IC.
If the whole thing gets too hot, then you need more mass.
But I doubt that will be necessary with the low currents you'll be employing.

yeah i noticed the warping and tightened it up a bit. I can always make it a bit larger but at the same time its going to be in an closed case with a fan? so maybe that will help out? if not like i said i can always expand it, i tested it for a min or so and the ic did warm up a bit but no where near like i had seen earlier, and the can does get warm aswell.