| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an inductive proximity switch with high reliability that has a large switching distance. SOLUTION: The proximity switch consists of a coil, a means that supplies a transmission current pulse with periodically changing direction to the coil, and a signal processing means that replies a voltage induced in the coil with an attenuation current having been supplied to a body to be detected by an inducted voltage resulting from the transmission current pulse after the transmission pulse is supplied. A pattern of a transmission current indicates that the transmission current flows in a 1st direction only for a 1st time interval T11 shorter than a half of a period T21 of the transmission pulse for the 1st half period of a period T21 and then is attenuated for a time interval T11' and becomes negligibly small for the remaining time T12-T11', and flows only a 2nd time interval T13 in a direction reverse to the 1st direction, is attenuated for a time interval T13' and becomes negligibly small for a remaining time T14-T13'.</p> |
