DIY Laser Torch

I see these type of batteries now in more and more handheld lights and in the grocery store yesterday. At the store, they were a little expensive. How well do they hold up under extended use?

Jon

Many thanks for the great guide.

I have a couple of questions if you don't mind:-

1) Does the LM317 in the TO-220 package fit okay? It is more of a square type package and seems a bit larger than the TO-39 package. Also in your photos it looks like you are using a TO-92 package?
2) In the parts list it does not have the diode or cap used. Is the cap the same value (47uF 16V) as from your "Homemade laser diode driver"?
3) I will be using the LD from SenKat's GB. With this circuit what will be the current & voltage supplied to the LD?
4) As we have a regulated current circuit how is the duty cycle of the LD? Do we still need to follow 60 on, 30 off etc?

Many thanks.
XG

Daedal - very well done tutorial, explanation, and video as well ! I love to see the innovation, and expertese going into these burners now, you all have far surpassed my expectations from the very beginings with your inventiveness ! That is a really nice build you have there, I assume the same as Xgeek - and the didoe is 1N4001 as before ? Now - from the pictures, you simply soldered the diode, and the capacitor across the terminals of the laser diode, following polarity and once together, it all fits very nicely ! One thing I would suggest to some of the folks is to mount those items on the wires themselves, and then run two wires to the laser diode - for simplicity, and to avoid too much heat on the LD - you SAY you have shaky hands, but your solering is impeccable ! TURD ! hehehehehe ! Excellent work.....

As far as the CR123 batts go - either batterystation.com, batteryjunction.com, and a few other places sell those batts as low as a dollar each in quantity - and they should last a good while to these diodes, as you are putting in 6v, and HIGH amperage, and only using a tiny amount of it for hte circuit ! Great work, in case I havent said that yet ! :-D

2) In the parts list it does not have the diode or cap used. Is the cap the same value (47uF 16V) as from your "Homemade laser diode driver"?
Okay reading the "Home made laser diode driver" post again I would say they are the same.

3) I will be using the LD from SenKat's GB. With this circuit what will be the current & voltage supplied to the LD?
After re-reading the "Home made laser diode driver" post I found my answer to this (2.3-2.8V going into the diode) (Just under 300 mA going into the diode as a 4 ohm resistor = 312.5 mA and we are using a 5 ohm (2 x 10 ohms in parallel)):-

If I am correct, then looking at the Sony data sheet would indicate the LD is running  between 190 mW - 240mW depending on temperature?

Copy and paste from the "Home made laser diode driver" post for reference.

Therefore, 6V - 3V = 3V to the diode. With most cases I have tried this I got a little past 3V and closer to 3.5V to the LD. The diodes we are getting from the SenKat group buy, and that is what this circuit is designed for, and most other laser diodes even, require between 2.5 and 3V to lase. With a 0.7V drop off the 3-3.5V supply form the LM317, you have a margin of 2.3-2.8V going into the diode. Which is perfect!

Click to expand...

As about the resistor, if you use a 4 ohm resistor, then you limit the maximum voltage to 312.5 mA. If you use a 10 ohm the maximum that will be passed through will be 125 mA.

Click to expand...

4) As we have a regulated current circuit how is the duty cycle of the LD? Do we still need to follow 60 on, 30 off etc?
If we are driving the LD with 300 mA then I guess it is best to play safe and limit the on time to a minute or less.

The 3 washers seem to make a good heatsink. On mine I may put AS5 between washers and try and get a tight fit between the AixiZ case and washers to help dissipate the heat.

Many thanks.
XG

joniverson said:

I see these type of batteries now in more and more handheld lights and in the grocery store yesterday. At the store, they were a little expensive. How well do they hold up under extended use?

Jon

Click to expand...

These types of batteries were designed for cameras, and cameras draw a much lower current than flashlights and lasers. There have been reports on CPF of explosions using these types of batteries. While I don't mean to alarm anyone, and reports of explosions are rare, it is important to exercise caution.

There are several things one can do to help prevent explosions.

1. Buy brand name cells.

2. Don't let them run down all of the way.

3. Invest in a ZTS battery tester so you can make sure each cell is testing even through the discharge cycle. Unbalanced
cells seem to be a big cause of explosions. So you would want to test the cells before you begin to use them, then periodically as they are being used, depending on usage.

http://thomasdistributing.com/shop/...P_id=&osCsid=4abf0cebb12a8738998b377400f375f5

4. Read up on CPF for more information. Following is one of the threads and is a good read:

http://www.candlepowerforums.com/vb/showthread.php?t=170187

xgeek said:

Many thanks for the great guide.

I have a couple of questions if you don't mind:-

1) Does the LM317 in the TO-220 package fit okay? It is more of a square type package and seems a bit larger than the TO-39 package. Also in your photos it looks like you are using a TO-92 package?
2) In the parts list it does not have the diode or cap used. Is the cap the same value (47uF 16V) as from your "Homemade laser diode driver"?
3) I will be using the LD from SenKat's GB. With this circuit what will be the current & voltage supplied to the LD?
4) As we have a regulated current circuit how is the duty cycle of the LD? Do we still need to follow 60 on, 30 off etc?

Many thanks.
XG

Click to expand...

You're very welcome... I just wanted to answer these questions very quickly...

1) I am not sure about them fitting in easily, but I can tell you that there is quite enough space int here to make it fit. I personally used the TO-92 package, but the spec sheet show that it is rated up to a maximum of 100mA and I did not want people using it and having it kill their diodes. I have personally tested mine though and it was on for about 5 minutes and there wasn't much heat from it at all. It could be a special case, or it could have been something else, either way, I'd rather be safe than sorry, and for that I advised to one of the other two packages.

2) The diode and the capacitor are the same ones from the driver guide I had made previously.

3) I am using one of the diodes from SenKat's GB as well. With 5-ohm resistance across the circuit, I have measured the output as very close 250mA. I can testify that this thing is AMAZING!! It is quite the burner as you can see in my video.

4) I am currently still testing that out. But I can easily say that I have had this thing on many times for longer than 2 minutes, with the maximum being around 5 minutes, and I have felt no heat from the diode... surprisingly!! I believe that with any help, these diodes can be driven like this on a regular basis. But I wouldn't advise not cooling it. I am merely trying to push the diode to its maximum and to see how much is enough.

Good luck to all and I hope you guys share your experiences;
DDL

SenKat said:

Daedal - very well done tutorial, explanation, and video as well ! I love to see the innovation, and expertese going into these burners now, you all have far surpassed my expectations from the very beginings with your inventiveness ! That is a really nice build you have there, I assume the same as Xgeek - and the didoe is 1N4001 as before ? Now - from the pictures, you simply soldered the diode, and the capacitor across the terminals of the laser diode, following polarity and once together, it all fits very nicely ! One thing I would suggest to some of the folks is to mount those items on the wires themselves, and then run two wires to the laser diode - for simplicity, and to avoid too much heat on the LD - you SAY you have shaky hands, but your solering is impeccable ! TURD ! hehehehehe ! Excellent work.....

As far as the CR123 batts go - either batterystation.com, batteryjunction.com, and a few other places sell those batts as low as a dollar each in quantity - and they should last a good while to these diodes, as you are putting in 6v, and HIGH amperage, and only using a tiny amount of it for hte circuit ! Great work, in case I havent said that yet ! :-D

Click to expand...

SenKat... I really appreciate your comments and kind words. I DO have shaky hands... but I also said I quickly put them to use when they're not as shaky . I'm glad you like the solder-work I have there and I do agree with you. It is much better to solder things to the wire going to the LD, then solder to the LD only once. As we all know, LD's don't like excessive heat. What I had done there was create that entice concoction and then heated it all once and slapped the diode on there. The diode barely saw 3 seconds of heat... if that.

As regards to the diode, I am using a 1N4001 in my setup, and a 47uF capacitor. I am sorry that I hadn't included that in the guide, and I will amend it all to include the new parts.

Also, just as SenKat said, CR123A batteries are VERY powerful. This circuit is barely tapping their potential, so they are probably going to last a very long time. I can easily say that I have had this setup on for well over an hour, and maybe 2. The batteries, however, seem just as good as new! The video was shot with the batteries when they have been used about that much too. The amount of power in two CR-2 batteries is much too tremendous to be affected by the little power we are drawing here. It will be a gradual fall over, perhaps, a month's use.

The batteries I have are the ones we had gotten from that eBay auction where they were damn near free! I, and a few other, got very lucky. They are the Panasonic ones IIRC.

Thanx again;
DDL

Hello Daedal,
I concur with everything you said. My post regarding battery safety was something I felt I needed to post. Having read the horror stories on CPF, I would feel bad if anything happened to anyone here and I had not posted a warning. My conscience was bothering me. I will feel better using those Panasonic Cells we stole off of e-bay ;D I am thankful you caught that in time for us to get them.

Regarding your measurement of 250ma output, I assume you mean you are driving the diode with 250ma's input? I have found the mw output does not seem to increase when going higher than around 250ma, except for when cooling the diode. I can only guess at this since I don't yet have a meter, and use blue electrical tape and matches to kind of get an idea of what does improve output. I have been able to light a non sharpied safety match at 6 feet.

There is no question these diodes are awesome burners. Even with 160ma input I am very impressed.

Thanx for the post about CR123A batts and their explosive nature. The truth is that anything with lithium is explosive. There have been many reports of such happenings, but all one can really hope is that it doesn't happen to any of us. I believe the CPF guys actually used to overdrive the batteries and then cause them to heat. Heating any battery, as was the case with all those recalls on almost all Sony made laptop batteries, will allow humid air to pass into the battery when the sealants give way. Lithium + water = a reaction you don't wanna be anywhere near! Let's just hope for the best though. A duty cycle not only protects the diode in this case, but the battery as well.

As about the LD's themselves. I absolutely love them. I am glad I got enough to test and play around with. With my drive at 250mA, I was able to light all the 14 matches as shown in the video from across a table 6-feet away. So, I agree with you being able to do that. This is one hell of an amazing laser, and quite the bargain I must admit.

--DDL

I am really looking forward to making one of these.
I have ordered enough parts too make 5 units and will sell 3 of them to the guys in the lab at work to recoup my costs.

Only found the forum a few days ago and I am blown away at how far things have moved on and how powerful these things are. I built my first laser back in the early 80s and the thing was huge. It is about 18" x 3" x 3" and has a sort of a long tube inside that is driven by very high voltage (Thousands of volts IIRC). Not sure what the power was but it must only be low mW. Now you get units that can pop balloons that are not much bigger than a large pea.

Only 18" ??? Crap, My first was 1 meter !! Had to sputter mirrors and use NaCl windows. You must be a new comer to Lasers !!! ;D

Mike

Thanks guys for the response. I was going to build this exactly as indicated but- due to the wait I keep having with dealextreme, I've opted for a slightly different route. My local department store has a Brinkman light that uses a pair of the 123 cells. More expensive than the dealextreme one, but I see the mod being done fairly easily. Will post an update when this is done. It won't be as detailed as this one though.

Jon

Daedal, GREAT tutorial. I ordered the flashlight from DX, so I should get that within a year. I'm gonna order some more diodes too. But thanks for the descriptive tutorial, I can't wait to make it! That one you made is a good burner!

Daedal or others,

This may be a bit OT here, but I have had quite a time fitting the LD's into the Axiz modules. The last one I fitted left marks all over the back of the LD to the point where I was afraid it would fail upon power-up.

I don't see any marks on yours, Daedal, so just curious as to how your pressing yours into the module?

Thanks in advance,
Jon

Hey Jon !  I know I am not Daedal, but I can answer that one for you, and others ;-)

With the Aixiz modules, as you know, there are multiple pieces to them.  Completely disassemble it, saving aside the front part (where the diode, and lense go) and the rear part.  Naturally, keep the other stuff, too LOL

• Place the diode pins first into the small hole in the back end of the module.

• Place the front end of the module over the front end of the diode - it will not "slide" in, since it is a tight fit, but place it in there anyways

• Now, holding the assembly together, put everythign into a bench vise - being careful to ensure that the two halves of the module are aligned mostly okay.

• Tighten the vise slowly, and the diode will be pressed into the front portion of the module without you having to use a hammer or other stuff ! (like the first few I did until I learned of the vise method ! :-[ )

That should cover it !  Remove the whole thing from the vise, and reinstall the lense tensioning spring, the lense, the lense cap (if present) and commence soldering, etc !  Please let me know if you think I need to explain, or snap a few pics !

nice job D i like the flashlight housing u chose