| 摘要 |
<p>PURPOSE:To provide a loop-coil switch which does not cause any malfunction by a method wherein a high frequency is used for the loop-coil switch for vehicle detection, a sensing coil is made compact and an in-phase current which is generated in a feeder supplying a high-frequency current from an oscillator to the sensing coil is suppressed. CONSTITUTION:In a loop-coil switch, a high-frequency current is supplied to a coil 1 buried and installed in a parking position through a feeder 6 from an oscillator 5 installed away from the coil, and whether a vehicle exists or not is detected by detecting a change in a resonance frequency. In the loop-coil switch, an in-phase current element coil 9 formed by winding a feeder on a high-permeability magnetic material is inserted across the loop coil 1 and the feeder 6.</p> |
