****MODERATOR NOTE**** This about wraps up this thread. We're getting into hair-splitting. . . . . . Running the risc of going on on this for too long I would like to ad something to this discussion Gary wrote: > For a loop of wire to "detect" metal, there must be motion. > It is the car passing over/into the loop which generates a current in > the wire. This current is then sensed. Hence, it doesn't matter > where the bike stops. If it has enough metal to generate the > required current to set off the sensors, it will do so when the bike > enters the loop. This is not entirely true: there is a small current running through the loop continously, generating a small magnetic field. The current through this loop is monitored the whole time and doesn't change when the surroundings of the loop don't change. When a car or motor bike or even someone with a wheel barrow comes along the metal (any metal, magnetic or not) will interfere withe the magnetic field created by the loop. because of this there will be a change in the current running through the loop and if it's within certain parameters (higher or lower) it will notify the lights of the presence of something. The statement on putting your bike near the loop-wire is true: the current-change will be more noticable so you will be detected, by just riding into the loop the changes will be filtered out as spikes and the lights will not register you. You can not compare a hand matal detector and those used for traffic lights; only their principle of operation is the same, but the applications are so totally different that the software for both "looks" for other parameters that change. If you've ever used one; a metal detector also detects metal when in a stationary position... In conclusion; YES the SS-framed car WILL trigger the traffic lights. Thanks for putting up with me ;-) JAN van de Wouw Thinking Different... Using a Mac... Living the Dream... Driving a DeLorean... #05141 "Dagger" since Sept. 2000 check out the Delorean-Files at: http://www.deloreanfiles.nl/ ------------------------------