The square plastic LD's CAN be put to use

Yea AAs have less internal resistance than AAAs so in a driverless build I'd imagine current will be higher.You should also keep in mind that the initial diameter of 5-10mm makes it easier for the light to be focused in a smaller spot.

whered you get the panasonic light from? :-?

Wait, so you have it connected directly to the diode?
you should probably get a driver in there...

I bought the flashlight in a local Danish supermarket...
But you can find it on http://www.panasonic-batteries.be/s...cts/products_torches_detail.asp?iid=8&item=32
About the driver. This is a simple build, using diodes that most people will not even bother to do anything with, if i were to put a driver in here then it would not be a simple build anymore. Just dont give the diode more than 3 V, and it should be fine.
And please read my first post...

You should at least use a resistor, this thing is not gonna last long, im surprised it even lit up long enough to take pictures. Why go through the trouble of building it at all if it lasts 3 minutes? Ive seen diodes get connected straight to battery's by people that didn't know any better and flash briefly, and thats it for the diode!

This topic is about bringing the square LD's to use. Not about driver vs. no driver.
And i have 3 diy reds, that are working fine without drivers - the oldest is a year old

I understand, my point is that if you are going to do it, why not do it the right way? I am amazed that you have one that lasted a year! You are either very lucky, never use it, or the diode is a freak. It is possible that these diodes will become more and more prevalent in drives, I would assume the company's may be under pressure to make them in a way that makes it hard to utilize the diode with all the bad press lasers have been getting lately... but when it really comes down to it, all you have to do is just put a lens in front of it. I also figure that these may actually be easier to make use of if you are going to build your own module to use it in. A flat surface is always easier to glue something to to get good heat transfer, you can even epoxy it to a pelter chip if you wanted to t.e. cool it.

A big part of getting a LD to last long is proper heatsinking, and not feeding it more than 3V.
I am not saying that a driver is a bad idea. But if you want to do a simple build, then keep it simple.
By the way the LD in this mod is supposed to be soldered to the heatsink(read my first post)

Just did a quick test with my lab power supply. At 2.4V the LD will use 120mah, and at 3.0V it will use 300mah (The power supply can go uo to 3A). I dont really see the big need for a driver here...

ok, you also need to check the current at 3.5v, I have seen new battery's add up to 3.5v. If the diode doesn't use more than your safe level of current, then it should be fine with out the driver... but im willing to bet that it wont be at 3.5v. There is a point where the current climbs extremely fast with just a small increase in voltage, as long as you never exceed this current, it should be fine. Also, remember that temperature makes a huge difference in the current required for a certain output power. What does it use cold? what about when it gets hot? The only safe way is with a driver, or making sure you never exceed the current that will cause COD. I think you understand these things I have said, I just hate to see a good diode die early. If you don't want a driver, by all means, don't make one. But it would be safer with the driver, its only 2 parts to make a working driver, an lm317 and a resistor, it will work without the cap, diode, 1 ohm resistor, and all the rest.. (ill probably hear about this from lots of people.) I have never had a single solitary diode die from over current surges because of the cap not being there, in my opinion this makes it safer without the cap than with it... since you don't have to remember to discharge it. I have built 20 or more lasers, and the only ones Ive ever had die on me are the ones that were physically damaged by outside influences, or connected to more power than they are able to withstand.. (rough extraction, droped on floor, shot out of vice grips accidently connected to 3 amps! ) this also includes a blue ray ps3 diode running at 38ma's. (no cap and works for over 11 months, used every day to point in class!!!). I have a "phasor " diode still running at 400ma with no cap on it, I use it every day, it hasn't died yet and is putting out 330mw! (I actually expect this one to die fast.) Had it since the phasor gb. I wonder how many people have actually played with not using the cap on the diode, I borrowed a scope and couldn't see ANY surge without the cap, but with it there is ALWAYS a power surge when the switch is switched off and on real fast. (like a loose connection) I think this needs more experimentation and testing to see if this is just my experience or is this the way the lm317s all perform. maybe I just got a good batch of them that don't spike when they turn on. anyhow, didn't mean to go off on a driver tangent, I just think it could use more experimentation.

Off course i am not going to put 3.5V through my LD. What brand and model of batteries did you measure to 1.75V each, and how much did you measure them at under load?  
I cannot measure my LD when hot, because i build massive heatsinks on my lasers(just look at the pics), and they dont get much hotter than room temperature.
I know that i may seem hostile about using a driver. But i really dont like people telling me what i cannot do - like this diode being useless, or "normal people" saying that it is impossible to build a powerfull handheld laser, or people telling me, that my diode will burn out within 3 minutes if not using a driver.
I believe in facts and experiments, and not hearsay from a internet forum.
My experiments tell me that a LD will be fine, as long as there is some good cooling to it.
My Ni-mh are 1.45V out of the charger, and that will drop to 1.2V after a bit of use, that is very much within the safe zone.
Another thing is, how many people are actually tuning their drivers, so they actually could delivers more current, that the LD would use - Say this LD will not use more than 120mAh at 2.4V - who would set a driver  for a 20X burner that low?
I would definitely use a driver for a more expensive LD, but for this project the time is used much better at building a really good heatsink.
We will probably never agree on this, but we have both built lasers, and we both seem successful in doing that. So maybe there are just more than one way in doing this.
/edit
There should be room for a driver in this flashlight, for those who want it

Its your laser, and your decision to not use a driver, I just think that using a driver is a much better idea than not using one at all, even using a resistor is ok. The battery's were lithiums I don't remember what brand. Im not trying to tell you what to do, Im just trying to help... If you understand the reasons for using a driver, then you already know what im trying to say, and why it is better.There are a lot of people that will read this and think: "wow, we really don't need a driver!" when most of the time you do... otherwise the diode will die real fast. (not in your case though)

I have a couple of these wth 4 pins, what are the + and - pins

If i remember it correctly, the two middle ones should be minus, and one of the outer ones should be plus.
be careful if you test it with no heatsink. then you should only give it about 2V.

I have a 16x from a year ago that is still going, without a driver.Pulsars just go and go, it really isn't something to be surprised about.Kipkay is not all that evil you know : People are just exagerating.

It is still way better to use a driver, not only for sake of the diode, but you'll get a nicer and steadier output.My flexdrive build is way nicer since it never gets dimmer until it shuts off, unlike the other one that just gets dimmer and dimmer until I recharge the batteries.

Thank you skrankesvin.