Quick question, need advice from the pros.

Ok here t goes, i have a laptop dvd burner and a desktop dvd burner. I have taken all the diodes out of all these. So i have 4 diodes. i have tested most of them with 2 double a's and they all light up red?. So i continued on my quest to make a homeade laser. I got a switch, double a holder, (a 100k ohm pot?)

So i built a circuit using these few things. I have all the polarity right, because when i just use the 2 AA's it works, but i get the LED affect. So i put the pot on and the laser diode is giving off no light now.

So what am i doing wrong and how can i fix this. Please don't link me somewhere else. And if there is any more information needed just reply and ill be glad to provide you with it.

Thank you so much for reading.

Brandon

You do know that 2 of them are infrared...and the other 2 are the red ones you want? Be careful until you are sure which ones are the infrared ones. Once you are sure, put a 47uf capacitor in parallel with the diode..and use a 2.2 ohm resistor. This is assuming your burners are at least 16X burners.

I do suggest you read through the experiments and modifications section of this forum.

Thanks for the reply, and what does it mean in parallel to?

Ok, well i managed to find all the necesary parts. The next question is how do i build the circuit. I am new so maybe a detailed outline of how to put the resister and capacitor together in it.

Your best bet would be to first read All of the posts in All of the threads listed in this post:
http://www.laserpointerforums.com/forums/YaBB.pl?num=1190456606
Of special note is:
http://www.laserpointerforums.com/forums/YaBB.pl?num=1185701612;start=all

Brandon said:

i have tested most of them with 2 double a's and they all light up red?

...

because when i just use the 2 AA's it works, but i get the LED affect.

...

Brandon

Click to expand...

Infrared looks red but blinds you...

The 'LED' effect is what we call a DEAD diode! :-[

--DDL

Any tricks to distinguish between the two?

If you can post pictures of the diodes....it might help....

I have found that the IR diodes are usually housed in a mount that seem to always have some sort of built in Lens....

While the red LD is left with an open path for the light to enter the lens chamber.....

Larry

Easy trick. Use a digital camera/camcorder/picture cell phone and take a picture of the diode's target. My solution to verifying infrared LDs was to set the diode to be tested without any lens approximately 6 inches from a piece of paper. Use the camera's screen (not viewfinder) to look at the target. If it's infrared, your camera will show a bright white spot present.

Always remember that some LDs are powerful enough to harm you even when not collimated or focused! Wear IR safety goggles or at the very least, a pair of IR blocking sunglasses when doing this.