Solder Complications - 650 nm Diode

Hey guys, putting together my first laser. Long story short ran into a snag.

I'm using an old computer's power supply hooked up to an LM317 driver (current around 240 mA). The diode I'm using is closed can red (650 nm; 250 mW I believe).

I just hooked up the diode to everything to make sure it worked before going through the trouble of soldering it up and it lit up brilliantly (rejoice!), so I went ahead and soldered the wires on.

I plugged it in again to make sure it worked before I pressed it, and that's when my heart sunk - it didn't light up at all. So, after cursing and moaning I desoldered everything and hooked the wires up like I had originally (just looped around the correct pins), and voila! It lit up again, just as bright as before.

So I wanted to get your guys' opinion on this, as I have absolutely no idea why it didn't work when soldered. A friend suggested perhaps the solder offers too much resistance to the current, but I've never heard of that happening before. Also, I had twisted the wire around the pins when I soldered them on, to ensure an adequate connection (as a faulty connection might've been the culprit), so I don't think that could be an issue.

Anyway, any advice would be greatly appreciated. Thanks in advance for your help.

From what you state above..... you have an obvious wiring problem..
or you bridged the LD pins when you soldered them..


Jerry

I was tending to say sloppy soldering too.
With these things the smallest error will prevent it from working.
I suspect that when you are assembling it without solder that you verify the connections by seeing that it is together.
When you solder it all you are making assumptions about the circuit and connections.
Double check polarity, connections and be sure that you have no shorts.

And "Hi" there to you.
Not the recommended first posting for a new member but I can relate to the excitement and wanting to get under way first thing.
:wave:

You guys were absolutely right, it turns out I did have a tiny glob of solder bridging the + and - pins. I fixed my mistake, re-soldered the wires and I'm back in business.

Thank you so much for your advice, I'm now the proud owner of a 3b laser =)

Feels great doesn't it, i remember my first dvd laser, welcome to your new addiction :evil:

The worst is when you get that glee of seeing the bright red hit the wall.. and then it disappears because it overheats...

Bionic-Badger said:

The worst is when you get that glee of seeing the bright red hit the wall.. and then it disappears because it overheats...

Click to expand...

Haha fortunately I've got the driver and module glued into their own heatsinks, so fingers crossed it lasts at least a while =)

pictures we need pictures

Haha sure thing! It's not pretty, but I'm proud of the little guy.

If anyone sees any obvious flaws (aside from being the furthest thing from portable haha) PLEASE point them out!


EDIT: Sorry, felt I should add the third picture. The arrows indicate which wires I used for + and -, and the red box indicates where I am planning on hooking up a SPDT (used as a SPST) switch (along the + wire). Again, any feedback would be awesome =)

NICE JOB those quality glasses make me smile
+1 for safety

Thanks a lot, man! Nice to know I got quality specs too =)

Also, while I'm here, any ideas on how to secure the module to its heatsink? I was thinking of drilling holes in the bottom of the heatsink and threading wire around it or something, but I'm sure there are better ideas out there. Thanks in advance for the help.

well you could use some thermal adhesive or drill holes and use some zip-ties instead of wire