Please help suggest DRIVER and/or troubleshoot mine

To start; I have searched the forum and can't find the answer...maybe I need better search skills or should pay my teenage son to do it for me...lol

Ok, so I apparently failed in my attempt at building a linear DDL driver (LM317) from a schematic I found online. It will light the LD but just barely. I (risked the LD) by connecting it straight to my 6V lantern battery WITH NO DRIVER and it definitely works better but still doesn't seem to be what I expected. The module does not even get warm to the touch without the heatsink. Can light a match (blackened tip) from about 18 inches in about 20 seconds and painful to my hand in about 2 seconds at 18 inches. My goal isn't to light matches; that's just my only way to relate it's power.

Can you help with a DRIVER SUGGESTION to match my parts? I will build my own again later, but for now would like to purchase the best one. I want the MOST POWER I can get from this LD, given my parts. Prob will buy a better lens, but for now need a great driver. It would be a bonus if the driver I end up with will work with future builds with perhaps a more powerful LD.

My Parts:
2 CR123A rechargeable LiOn 3v batteries
1 alkalyne 6v lantern batt (the big square one)
1 SLD3234VF 150mW ultraviolet 405nM diode from Anomalytech (in an Aixiz module)
445nm 405nm Three Element Glass Lens for Aixiz Module from DTR
1 45 mm x 20 mm x 25 mm aluminum heatsink for Aixiz module
Plenty handheld flashlights for host...leaning toward my cheapo Harbor Freight ones.

Bottom line: NEED a DRIVER SUGGESTION.

Thank you in advance for reading my post and for any advice you can give. I will certainly do my best to help a noob when/if I ever have something to offer...

Thanks again, sgtbilkodle

Learning from your mistakes is a better option than giving up and starting something else, yes?

Operating under the assumption that you've followed the schematic appropriately, and judging from your supplies, my first guess is that your voltage input is insufficient for your choice of laser diode. The lm317 (when operated in constant current mode) needs at least 3.5V more than the forward voltage of the load. This is called the minimum voltage dropout. The forward voltage of a violet laser diode is typically somewhere between 5 and 6 volts I believe. That means you'll need 9V input at the very least.

Also, NEVER connect a laser diode to a power source without a driver. You're incredibly lucky it (probably) isn't dead.

I have a couple boost drivers that'd work great for what you need. I can change the set resistor on it and set it to the right current for the diode you're using.

All you'd need would be one li-ion battery. I could also put some leads on it too, for $18 total including shipping.

Or, a linear driver that'd work with two li-ion cells to give you what you want too. That would be $16 including shipping with the leads attached.

Not to mention the driver could be used/changed for something higher power in the future too.

And presumeably, the Li-ion batteries you have aren't primary cells, right? If they're rechargeable they should be 4.2 volts when fully charged. If they're 3 volts then they aren't rechargeable.

Lemme know what you think.

Very good advice Cyperon. I didn't consider my VDC source was too low for the LM317. I did have the 205nm LD's voltage in mind though. Also knew better than to hookup the LD straight to the batt without a properly set (for current) driver but was willing to blow it, as I just ordered a 2W M-Type M140 445nm diode from DTR minutes ago. Per your advice on VDC; I will hookup 9V tomorrow hopefully. PS...I think this 150mw rated LD will take the bare 6V battery continuously as long as the batt is fresh..then The current might drift. Am I off?

PM'd ya Le Quack; thanks

Y'all keep the answers coming tho! This forum rocks!

sorry man; i just did negative rep on you and meant to do positive...i will send positive as soon as it lets me, twice.

sgtbilkodle said:

I think this 150mw rated LD will take the bare 6V battery continuously as long as the batt is fresh..then The current might drift. Am I off?

Click to expand...

Yes you are off, don't do that, as the diode heats up it will draw more and more current. That's why laser diodes require a constant current driver, not constant voltage.

sgtbilkodle said:

sorry man; i just did negative rep on you and meant to do positive...i will send positive as soon as it lets me, twice.

Click to expand...

You didn't neg rep either of them. It's meaningless to rep someone until you have 50 posts and rep power of at least 1.

Also you must avoid double or triple posting, the moderators don't allow it. Learn to use the edit and multiquote buttons, then wait for a reply or edit your last post to say more.

Here is some rep for you for at least trying to build a laser.

Alan

Thanks Pi R Squared for the info. That LD never did get hot. It's longest burn time was maybe 2 minutes continuous, monitoring the temp by feel, it barely warmed. Heat was imperceptible on the actual heat sink. As per your advice AND the advice I gathered from reading throughout LPF before doing it; I won't do it again. Was really not caring if that particular LD died; just wanted to see it burn (through proper goggles, of course)!

OK, so anyone with a good driver suggestion?
-2W 445nm M-Type M140 Blue Laser Diode from DTR
-405-G-2 glass lens and your copper module from DTR
-I have built the host with 3 RCR123A 3.0V 750mAh LiFePO4 Rechargeable Batteries in series. Output voltage is around 9.5 volts with momentary surge of 10.4.

What's the best driver for this?

If you must use that battery combination then I would buy that linear from Le Quack if he has one he set at between 1.5A - 1.8A, or go here: http://laserpointerforums.com/f39/x-drive-x-boost-88589.html and scroll down the page and find the X-drive V6 at 1.7A or 1.8A, if you scroll farther down the page he has an option to solder 2 or 4 leads to it, I think they cost $26-$30. Don't get a V7 X-drive or you may blow that thing at over 9V. I am assuming you can pay with PayPal.

Alan

Thanks Pi R Squared. Le Quack is working on 2 drivers for me now...