Yesterday's IR Handheld Project

Well, yesterday was a very rainy day where I am, so I decided to make a handheld IR laser (my third). My previous IR handhelds, both 808 nm, 1 and 2 watt, were based on 2 x 18650 battery power, current regulation by LM338. This time, I wanted to produce a much smaller laser, but still get about 2 watts of 808 nm output, so I made some design changes. I used 1 x 18650 battery power, and I got creative on the current regulator. I had purchased from DX some 350ma and 1050ma 7135 based flashlight regulators a while back, and had many left over. Current regulators can be parallelled for more current. I made a compact stack of 2 of the 1050 ma and 1 of the 350 ma. Testing the result showed that a current of 2.65 a would be delivered to my diode. Since my diode is rated 2.8 a maximum, I figured that this would be safe. I went to my machine shop and made a machined aluminum host and matching c-mount heatsink enclosure with focusable optics. I went with positive ground as the c-mount diodes are also positive ground. The 7135's are a negative side regulator, so this works perfectly with a positive ground system. The resulting laser is not much bigger than the red DX200, photo attached shows my new IR next to the DX200 red.

Summary :

Power                1 x 18650 Lithium Battery (DX)
Diode                 808 nm c-mount 2.0 watt (from ebay - snoctony) in custom machined mount
Regulator           Stack of 3 DX flashlight regulators 2 x 1050ma + 1 x 350ma
Host                   Custom machined from aluminum stock
Lens                   Aixiz glass lens was cemented into my own brass threaded focuser

Results :

I am extremely happy with this laser! It is quite small, has a solid feel to it, and looks good. Output seems quite strong although I have no method currently to measure a laser over 120mw. This laser lights a candle nearly instantly. Electric tape usually catches fire when being cut. A black plastic film can is instantly perforated. Matches light instantly. Wood burning even on light colored wood is easy and quick. Of course, anyone making a unit like this should have appropriate goggles. This laser has enough aluminum to it that it does not heat up during use.

WOW!

How is the divergance? I've heard 808's don't focus well, and are only good for close up burning. How visible is it? I would imagine a NIR 808 would be about as visible as a typical red pointer, because I can see a dot on the wall from my 75mw 808 in a dark room when I look close.

Could we get some shots of this bad boy in action?

I would love to have an 808nm burner if only someone could collimate one well!

VERY nice work!

EVERYBODY here would love to see some action videos of this thing's power!

You're right, the divergence does suck on these diodes. I have two lens assemblies for this laser. The first allows burning from 0.25 to about 4 inches, the second goes from 1.5 inches to about 6 feet. There is some visibility to the 808 nm. The spot is clearly visible bright red, which helps with focussing. As large volumes of smoke are produced by the rapid burning action, you sometimes get to see the beam passing through the smoke. The attached photo shows some IR stuff. The big laser at the bottom is my other 2 watt 808 nm, using 2 x 18650 and LM338 regulator. The laser above it is a 1 watt 808 nm, 2 x 18650. The gold brick on the right is a Coherent 60w 808 nm water cooled. Sitting on it is a Coherent 40w 808 nm. To the right of the c-mount tray is a c-mount head apart. Beside it are two more completed c-mount heads for other projects. The other two lasers at the left are the new one I made yesterday because it was raining, and for size comparison, the well known DX200 red.

I also made a few videos.

Here is the obligatory match lighting video ...

wow really nice! I love the aluminum bodys you used. looks professional and original.

WOW, awesome!! Nice match light How much did the diode cost? They look like lightsabers :

*Very* impressive lighting of the match. Good to see that you didn't go the easy route, and just try to ignite the tip.

Only a real man's laser can ignite the match from the center of the wood!

Switch : The diode used in this laser was purchased on ebay from "snoctony" for $70 plus $20 shipping.
I like the form factor of this laser. Compact and powerful. I was going to do a tape cut video, but
the tape just kept catching fire, so I gave up.

I should have mentioned that in the first video, the laser cuts 1.25 mm solder, twice.
As far as the match light from the middle of the match, I am sure that I've seen this a few times on youtube, so I thought I'd try it. Works well. Lit a sparkler, too.

I gotta get to building one of those sometime It's pretty cool , cause you can light the same match multiple times :

Do the DX regulators you used come separately or did you have to rip them out of flashlights? And if I may ask, what voltage and current is it running at? :-/

Definetly got to get me one of those, but I need to save money for at least 2 pairs of goggles so I can show off to people ;D

i've been wanting to paly around with such cmount diodes, but also wondering how to connect/solder them to power/driver?

Excellent workmanship, loved the solder video. You have 808nm blocking goggles right From the looks of it you are planning on building a few more? Will you be selling?

Switch : DX sells these regulators real cheap in 5, 10 , and even 20 packs. They have 350, 700, 1050, and 1400 ma. These are perfect regulators for IR portables because, based on the 7135, they are negative side. The IR diode is positive ground, so these regulators let you use a positive ground system in your portable. My stack of three regulators is delivering 2.65 amps to my diode. It should live a long and happy life. You can light the match several times, light candles and sparklers, firework fuses, burn through thick dark plastic. Tape, paper, and wood like to catch fire.

Natabata: Body of c-mount diode is positive, little gold tail that comes off is negative connection. Power it from a current regulator, depending on requirements of diode, you may need an LM350 for 3 amps max, or even an LM338 for 5 amps max. Resistor is calculated just like for LM317, as the 350 and 338 use the same internal reference volatge of 1.25 volts. C-mount must be heatsinked and enclosed, like an open can red, the junction is exposed and can be damaged by contaminants, resulting in COD.

drlava: Yes I have goggles, both for myself, and for visitors. Kind of necessary when I get out the Coherent brick and burn some 2" and 4" pvc pipe, and whatever else is lying around. Only fun if you keep your eyesight.

Attached is a little video of this little laser and a small steel wool pad.

How much would I have to pay you to build me on of these?

yea if you ever want to sell some or do a custom job that would be awesome