| abstract |
A magnetic-field-dependent inductive proximity switch having a coil arrangement with a ferromagnetic core, which is saturation-sensitive with respect to the magnetic field to be picked up, and having an electronic analyzing circuit for triggering a switching process at a certain core saturation, is to be constructed so that its power requirement is very low, for example, in the range of 0.1 to 5.0 milliampere, and that, by means of said switch, a magnetic field can be picked up through a non-ferromagnetic wall and can be used to trigger switching operations. According to the invention, it is provided for this purpose that the coil arrangement is the inductive element of a high-frequency oscillatory circuit, the high-frequency oscillatory field of which, in the direction of the side of the magnetic field to be picked up, is essentially enclosed within the switch, and the oscillatory amplitude of which depends on the degree of core saturation, is picked up by the analyzing circuit, which, when an amplitude threshold value is not reached, triggers the switching operation. |