| 摘要 |
An inductive proximity switch for detecting the presence of an object in a monitored area includes a coil (2), a pulse source (4) for supplying the coil (2) with transmitting current pulses (S1, S2, S3) at a period (T) larger than the duration (Ts) of the transmitting current pulses, and a processing circuit (6) for generating an output signal (9) based on received voltages (Ui1, Ui2, Ui3) varying in dependence of a change of position of the object. The received voltages are induced in the coil (2) after the duration (Ts) of a transmitting current pulse by the decaying current which previously flows in the object due to the voltage induced therein by the coil. The proximity switch has a suppression circuit (13, 13a, 13b, 13c) for suppressing a signal duration lower than a predetermined perturbation time (Tc1, Tc2) in the output signal (9).
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