Safety system has transportable electronic miniature radio transmitter, receiver tuned to transmitter for fitting in vehicle; transmitter range corresponds to stopping distance in urban traffic

摘要

The system has a transportable electronic miniature radio transmitter and a receiver tuned to the transmitter for installation in a vehicle. The range of the transmitter corresponds to the stopping distance of the vehicle in urban traffic. The transmitter has a motion of position sensitive device so that it only transmits if the transmitter moves and/or for a short period thereafter