May i have your answer , ASAP please....

[Abeer_engjbr]

Hi every one ,
May you help me , How can i know the polarity of the IR leds ? and how must i point them in order to get good transmission?
Waiting for you answers .
Thanks.

 

[Hero999]

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.

 

[Abeer_engjbr]

Thank you Hero999,,,

 

[Norlin]

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

 

[HS3]

May i have your answer , ASAP please....

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.

 

[Gayan Soyza]

and how must i point them in order to get good transmission?

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.

 

[Abeer_engjbr]

Hi
For HS3,thank you foryour opinion but realy will stay as I want ,and write in the way i see.
If you don't know the way to share your knowledge without jugdeing people from there way of writting then don't bather typing your reply,because you will waste everybody's time .
All The Best.

 

[Nigel Goodwin]

Hi
For HS3,thank you foryour opinion but realy will stay as I want ,and write in the way i see.
If you don't know the way to share your knowledge without jugdeing people from there way of writting then don't bather typing your reply,because you will waste everybody's time .
All The Best.

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.

 

[Abeer_engjbr]

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.