ENGINE OPERATION DETECTION

摘要

A method and apparatus is provided for determining if a vehicle with an operating engine is at a particular location, the apparatus comprising: an antenna comprising a continous wire formed into at least one loop; and a means to determine when the antenna is exposed to an oscillating electromagnetic field having a frequency between about 700 and about 2100 Hz of a strength characteristicof a vehicle's alternator operating in the vicinity of the antenna. In a preferred embodiment of the present invention, the sensor of the present invention futher comprises a means to generate a signal when the antenna is exposed to the oscillating electromagnetic field having a frequeny between about 700 and about 2100 Hz of a strength characteristic of a vehicle's alternator operatingin the viciniy of the antenna, and the signal is used as an input into a logic system that requires that the signal not be generated in order for a refuelling system to refuel a vehicle in the vicinity of the antenna. The antenna is preferably a figure eight loop antenna placed in pavement below the location at which the vehicle is expected to be. The sensor of the present invention is particularly applicable as an input to disenable a fuel pump at a refuelling station.