How do transponders work?

[Kermit]

Does anyone know how the non optical (ie IR) transponders operate? IE what technology does it use to transmit the ID to the comp?

[HyperLosi]

the transpnder system works by means of a wire usually burried under to track (offroad) or above (onroad). the wire emits a frequency that the transponder in your car responds too. each transponder emits a slightly different frewuency so that the computer can tell what car is which. if i am wrong in any way lmk.

[mab_man20]

To continue HyperLosi's info, the transponder continously sends a signal to the wire on the track. The computer picks up this signal and when the signal is the strongest, the computer assumes that you are directly on the loop so it counts a lap.

[Kermit]

How do they generate the different freqs? Does it use a crystal osc? Or are they using a digital signal of some sort?

[Vmax911]

Not sure about all systems, but I've seen Ko Propo setup and they actually use different crystals just like a normal (non synthesized) radio system.

[HauntedMyst]

I took apart our KO system and it turns out, they are empty inside. Well, not empty. Inside each transponder is a small trained monkey. Every time you pass over the wire, the monkey reaches out and slaps the wire, triggering the computer another lap has passed. Some people will cheat and teach their monkey to slap the wire with both hands, making the computer think 2 laps have passed, but those people and their monkeys are just lame.

[Grizzbob]

Ahhh, so THAT'S what happened to Sea Monkeys......LOL:p