FreeTrack Forum

I'm using the radioshack 940nm high output IR Leds with a 3 AAA battery holder, with 10ohm 1 watt resistors. Even when I wire one led directly to my battery holder, it still doesn't light up! I tested it with my smartphone, and I am so frustrated with this. Please help!

Even when I wire one led directly to my battery holder

maybe that one is now "dead"
Leds are diodes, that means that they have a positive side and a negative side.
If you connect the led good you can see it light-up if connected wrong you don't see it light-up.If you put three of them in serie and one is connected wrong they don't light-up.This is because one is blocking the current going through because of its diode property.
If the forwarding voltage of your leds is 1,28Volt, you can test him by connecting him to ONE rechargeable baterry of 1,2Volt and see if it light-up.

if it is this Spoilerhttp://www.radioshack.com/product/index.jsp?productId=2062565 one, your forwarding voltage is 1,28Volt,
(powersupply - total forwarding voltage) /resistor = current( in ampere)

(4,5V - 3,84)/10ohm=0,066 ampere     66mA
batteries run empty, this is a better solution.You only need to change the value of you resistor for one of at least 15ohm.