d_a_parker

Maybe! That's the best possibility I've seen so far. The problem is, I'm not 100% sure if the Big Trak sensor is a photodiode or photoresistor, and there's a difference. One needs a voltage applied and the other does not. I'll probably need to pull the board from the Big Trak and do some testing to see if I can figure out exactly what's on it.

Thanks. I've been looking online but haven't found an IR LED and photodiode pair that both look like the ones in the Big Trak. I'm hesitant to remove the old ones and put in something totally different, without at least knowing if the specs on those parts are similar. It's crazy that nothing is labeled in that thing. An interesting project, though!

That's actually the same site I found when I was first looking into this, but they just refer to these as "emitter" and "detector". I know it's an infrared LED and it looks like maybe it's driven by 6V DC, but I have not been able to find the exact specs on these parts anywhere. The board itself is not labeled. Maybe I'll just need to buy an IR emitter and detector pair and see what happens. Thanks!

Hey everyone, I recently acquired an original Big Trak (1979) but it has a few issues. I have traced the biggest problem to the fact that the wheel sensors are broken. There's a small circuit board with an emitter and receiver on it which look like LEDs, but one of the two is literally cracked in half. Looks like a fairly simple repair if I knew what the specs on these parts were, but I can't seem to find any information on them anywhere. Does anyone here know what type of emitter and receiver these are? If not, anyone know of another place I could look for help? Thanks!