I am playing with some infrared leds and phototransistors. My project is a pinewood derby timer. It's computer based and I use a usb data acquisition box so the circuitry is pretty simple. I am a bit confused about the emitter and detectors I bought. I got the radio shack 276-142 pair. Now... with my tv remote I can aim it over my shoulder, without looking, bounce the beam off the wall and it will work great. With these leds I have to push the current to 100mA+ and even then they have to be very close (not more than an inch) and almost perfectly aligned. Does anyone know of a better emitter and detector to use?