Flashlights/Step-Up for violet laserdiodes?

[krutzbeuazen]

RDZombie,

actually i had a look at those converters, and read through most of the comments. they seem to be quite bad from efficiency, but that wouldnt really matter for violet lasers, and under 50mA needed..
a simple test for them would to connect two LEDs (blue, white, violet, all have 3.3v drop) in series. if they still light up, the circuit outputs high enough voltage. for regular "small" LEDs, 4 pieces should be used, two in series, and those two strings parallel. if they still light up as bright as normal, it should equal 6.6v with 40mA. or better, connect those 4 LEDs, and measure the current with a multimeter between the circuit and the LEDs.

why i write this noobie-testing method?
i dont trust those circuits and my multimeter any more. i put a 100uF capacitor across the output of one circuit, and still measured around 50v. and then that extreme "i lose all current at slightly higher voltage" behavior..

anyway, i am very interested in what you may find out about those circuits!

manuel

 

[Corona]

snap shots of the different boards and post em up

That would be great; try to maintain the same scale or at least the same angle (straight on, ideally) when photographing them so it is easy to reverse-engineer the circuit - I layer them in an image editing program, reverse the back side image, and from there it's easy to see where stuff is interconnected.

Try to avoid using a flash, or at least diffuse it through a piece of tissue paper, to avoid hard reflections...

This assumes they show ANY promise to begin with. But I'm always interested in seeing what's out there and how it can be improved (if necessary).

 

[laserblue]

interesting post. On the maxim website they have lots of charge-pump chips that could be used as step-ups as well

 

[Kenom]

OK so in this thread you indicated that a UV led requires about the same juice as a bluray LD. would buying a keychain UV led light provide you with the right circuit and whatnot to drive a bluray LD? I'm looking at this in particular.
http://www.photonlight.com/UV-Ultra...ED-Lights-p/uv-ultraviolet-led-blacklight.htm

Now I won't mount the laser diode onto the light like this guy did.
http://www.laserpointerforums.com/forums/YaBB.pl?num=1193418681
but I'm considering pulling the driver from it and using it in my own host. it's off button cells so it shouldn't exceed any voltage or current requirements of the driver (i hope)
I found this little flashlight that I know has enough room for the module but I've gotta find some means of driving the LD at the right current and voltage. I was just gonna run it straight off some smaller button cells like 4 or 5 1.5v cells

here is the light.


now the light currently runs off 3 cells but there is room for one more.

 

[karlthev]

Hey, that looks JUST like my LS First Run in the background Ken!!!:devil:



Karl

 

[Kenom]

Hey, that looks JUST like my LS First Run in the background Ken!!!:devil:



Karl

YOu betcha it's gonna get turned into a nice laser for ya!

 

[krutzbeuazen]

ken:
i didnt take any measurements by myself actually. but for what i know, white, blue and uv leds need 3.3v at 20mA, and the bluray diodes take anything between 4.5v and 5v and 20mA to 30mA for lasing-treshold. with high variage, so every diode *must* be measured individually. what i want to say: blu-ray diodes need a higher voltage, and they dont run in 1w LED flashlights (being driven by a single AA cell, from DX).

if by "driven by 3 cells" you mean lithium coincells, it should work! i tried alkaline buttoncells, and even 6 in a row worked only for a few minutes, before the voltagesag reduced the current..

if you dont have to invest too much, give it a try!

manuel

 

[RDZombie]

That would be great; try to maintain the same scale or at least the same angle (straight on, ideally) when photographing them so it is easy to reverse-engineer the circuit - I layer them in an image editing program, reverse the back side image, and from there it's easy to see where stuff is interconnected.

Try to avoid using a flash, or at least diffuse it through a piece of tissue paper, to avoid hard reflections...

This assumes they show ANY promise to begin with. But I'm always interested in seeing what's out there and how it can be improved (if necessary).

Still workin on those pics guys, my digi cam is not the best and doesnt like the close up shots (refuses to focus) I bought it to take pics of motorcycles im selling. Going to try to barrow a nice cam form work...

 

[RDZombie]

OK guys, i cant seem to find the other 3 boards i bought from DX but these are the 2 i could find. first one is DX P/N 4735, second is P/N 4451

Image quality isn't the best as I couldn't get a good cam, also to get it in focus I had to take the pic through a magnifying glass lamp thing LOL

 

[dr_lava]

I had an older elly with the external FET laying around and converted it to a violaser. Had to add a 10uF smt capacitor on the battery side of the PCB to boost the output. The laser drew about 34mA with a drop of 4.6V for 10mW output, so a 12 ohm resistor was put in series with the diode, with another smt cap after that to smooth out the switching spikes somewhat. The battery draw is about 180mA.

so, just FYI, if you have an old elly around it might be worth the effort.

 

[dr_lava]

we might want to check this board out, as it's adjustable with a pot and can produce the V levels needed for the violet:

http://www.dealextreme.com/details.dx/sku.7882

 

[RDZombie]

we might want to check this board out, as it's adjustable with a pot and can produce the V levels needed for the violet:

http://www.dealextreme.com/details.dx/sku.7882

I just picked up 2 of these even though I haven't even messed around with the others I have bought (and picked up another 20mw greenie) I cant stop buying crap from DX; its all so cheap. Its horrible!

 

[dr_lava]

I just picked up 2 of these even though I haven't even messed around with the others I have bought (and picked up another 20mw greenie) I cant stop buying crap from DX; its all so cheap. Its horrible!

yeah I know what you mean just cheap enough to be 'impulse'.
this thread has a post that tells you one way to disable the flashing from the pic (mcu)
http://www.cpfmarketplace.com/mp/showthread.php?t=169324&page=2

 

[liveforphysics]

Quite a long time ago, I solved the Violet LD driving problem by making a bucking type controlled and adjustable power supply. I used a pair of half AA size li-ion cells in series to avoid the need for any switching power supplys or spike related issues.

The hardest part was making it all be the size of a dime, and I didn't want the complete package size to be larger than my finger.

Here is the driver.

Here is the whole thing.

Best Wishes,
-Luke