froncio@caip.rutgers.edu (Andy Froncioni) (03/13/91)
Hi, I've posted several times on this newsgroup asking for various electronic solutions to autoracing problems. And since I've always gotten good responses from you folks, I've decided to try yet another project. Here it is: I would like to design a sensor to record lap-times of one particular car during a race. Now the car will be racing alongside twenty or more other cars so I have to be able to "tag" it somehow. The environment will be quite hostile to radio or audio signals as the engines use an electronic ignition coil that radiate spikes 300 times a second. Some basic guidelines are that I am not allowed to lay down any wires on the track. Nor am I allowed to hang long wires over the race track. I would also like to avoid "illegal" transmission solutions, though I imagine that this is not a very difficult restriction. I will have access to a trackside computer in order to store the lap-times. Any responses would be greatly appreciated. Thanks. Andy Andy Froncioni CAIP Center Parallel Computing Lab froncio@caip.rutgers.edu Rutgers University, Piscataway, NJ
bame@hpfcbig.SDE.HP.COM (Paul Bame) (03/14/91)
Since the RC track is hostile to RF and audio, how about using (again) light. Place an IR LED on the car modulated at 40KHz and arrange one of those IR receivers so it can only "see" the car after it passes the point of interest. You probably don't have to worry about the 20mA or so the LED will require compared to the 10A draw from the motor. You will have to worry some about clean power to the LED/Oscillator if you run from the same battery powering the car. -Paul Bame bame@fc.sde.hp.com N0KCL