Using keychain red laser driver w/ these diodes ?

Hello !

I have an old toshiba dvd rom and lg cd burner for disassembly here.
Id like to use one of their diodes to make myself an IR laser (-pointer)
as a basis for further projects. I once took one of those key-chain
red laser pointers apart that uses 3 small button cells. Would it be possible
to use the driver pcb for one of the cd/dvd drives diode ?

Some pictures of the parts i have:

If not, id ckeckout the diy-driver from the faq-section.

Thanks in advance,

Frank

Re: Using keychain red laser driver w/ these diode

You'll probably want to use a real driver.. that just looks like a simple resistor with a diode and mofset to prevent problems with reversed polarity. The only reason it doesn't kill the laser is because the coin cell batteries have such a high internal resistance and can only put out a dozen mA or so.

With higher powered diodes like those found in burners, you'll need to provide more current than those batteries are capable of, and regulating the current becomes something important since high powered semiconductors throw off a lot of heat, laser diodes have lower resistance when heated, soon leading to a thermal runaway situation and a dead diode.

If you've never built lasers before, I'd suggest making a red one. Playing with IR is sorta dangerous and boring since you can't see what you're doing. I'd also suggest making a full-size one to start with, then trying to miniaturize it later. Buy some aixiz modules and either some prebuilt drivers off the forum or parts for your own drivers from radioshack or something. You may have lofty ambitions, but you still must master the basics first.

Re: Using keychain red laser driver w/ these diode

Weird I've not found a cheap keychain laser with a pot yet.

Re: Using keychain red laser driver w/ these diode

..at least one solid reply! Thanks pseudolobster !
Yep, I will try the diodes with that driver from the faq.

Youre quite right: IR surely is dangerous.. The idea
behind using the old IR diodes is to build myself
a lightsource to experiment around with my digicam
and to have nightvision, sorta. I would then make the
beam disperse at least theoretical. From the tuts ive
found so far one would have a great bunch of IR leds
assembled together which are very expensive, at least
the powerful ones..

FFB

Re: Using keychain red laser driver w/ these diode

@jonrobertd:

This was out of a 5 eur keychain pointer i just bought
to get the included 3 button cells. Wouldnt recommend that
though as they have drained veeery fast

Re: Using keychain red laser driver w/ these diode

Sorry for the pathetic post. Just out of the 100 or so cheap pointers I trashed, none had pots.
As far as the IR laser I too have wondered about this as I now have several "chip" style ones and thought about making a laser assembly by stacking them or making a square |_| arrangement to use for a similar idea.

Re: Using keychain red laser driver w/ these diode

;D just kidding because ive posted this on weekend and
thinking of getting these babies running soon (and somehow)
but got no replies at that time...
Yes, i too think that for example this square idea should work,
onetime i opened up an old dvd player and on my cams display
i could see clearly the beam when the drive was accessed.
While having the beam diffracted or diffused by some kind
of prisms or lens arrangement why not have this as a source of
IR light that a digicam catches then ...?!
So far ive googled seems no one has done this..

Re: Using keychain red laser driver w/ these diode

Hey Frank
I wouldd hold onto that pbc if I were you. That looks like a perfect button to use if you ever make a pen laser with a flexdrive. If u short the spring and the botton and the other end of the button to the driver. People have made IR lasers before for night vision goggles and such, but it is not every ones favorite because its invisible coherent light and could potentially be dangerous w/o proper goggles.

I would use some of these for night vision instead.
http://www.dealextreme.com/products.dx/category.917~search.ir
The LED star lights are very bright, and you would probably only need one or two.

Re: Using keychain red laser driver w/ these diode

Wheew! Thats link is pretty good!! Thankx pwnstar!
Since i saw that vid tutorial from, i think it was a KipKay
one    where hed used ir-leds (12 or so) and these
were peculiar, strong intense leds. His night-vision was
pretty well and i remember that as he walks around in the
house you could see all the objects in the rooms..

me of course would take at least twice the leds in my configuration.
And i would make ome mirror arangements...

Id like to take some pics from the environment, animals..
I own a Canon 1ox optical zoom and thought of then being able
to spot e.g. a bird from a distance, not to be disturbing it that much.
Therefore you would need a far strong ir-lightsource at nights ..?!
I wonder if its harmful to these animals when exposed to ir in so
conditioned areas...
The female of the Blue Tit, Cyanistes caeruleus, actually prefers male who are reflexing the most of the natural UV light with their feathering..
Another em-frequency human eyes cannot sense    :-/ ..

Its curiously amazing to see those IR 48 LED Illuminator
at dealextreme when a similar gadget but w/ less ir leds, is around 100eur
here..

Since holidays are coming I checkout some diodes with a selfbuild drver..

Frank

Re: Using keychain red laser driver w/ these diode

I was in the Army in Europe in the late Eighties to early Nineties, I used and worked on these a lot:

http://nvdepot.com/goggles/pvs5c.asp

The power switch was 3 positions - Off, On, IR.

In the IR position, it would turn on a single IR LED that was right between your eyes.
With that thing on at night, it was like wearing a spot light on your head looking thru the goggles.

So, based on that I'd guess you only need a single simple IR LED - I would start with a old remote control: tear it down and pull the LED from it and start tinkering.