Connect them to a 3V power supply in series with a 150hm: resistor and measure the voltage across the LED with a DVM. If it reads the same as the power supply then it's connected backwards. If it measures between 1.2V to 1.6V then it's connected the right way round.

__________________
I also post at the following sites:
http://www.stop-microsoft.org http://www.heated-debates.com
Screen name: Aloone_Jonez

 

 

you can also look at them through a digital camera, when it's on it should give a purple colored light through the camera screen

 

Yes, you may. Here is my answer: If you use descriptive titles for your threads you will get much better response and it helps the rest of know what it is about without having to open every thread to find out. Also, huge letters, fancy colors and other gimmicks are annoying as all get out. It is best to use simple, carefully composed English.

 

Single IR LED fairly working well as you can see on many remote controllers.If the range is not enough you can series another one or two IR LED's.

I'm using a single IR led with a low duty cycle on them.So I can drive them using extra power than its rated.

__________________
Gayan

My Website
http://gsmicro.blogspot.com/

 

 

Perhaps you've noticed you don't get very many replies?, like many here I simply ignore any questions in silly fonts, colours, and sizes.

Basically posting in such a way is considered 'bad mannered', and your response to a polite comment is also bad mannered.

__________________
PIC programmer software, and PIC Tutorials at:
http://www.winpicprog.co.uk

 

I want to apologize to HS3, and all of you. I promise I'll learn from my mistakes.
If it's worth to know my project is finaly completed , thanks to your help and guaidness.