Patent ID: 7106052

Claim:
Inductive proximity switch with a pair of transmitting coils, having a first transmitting coil (S 1 ) and a first receiving coil (E 1 ) of a receiving coil arrangement, the first transmitting coil (S 1 ) and the first receiving coil (E 1 ) being disposed coaxially relative to each other, the transmitting coil (S 1 ) transmitting an exciting field for inducing eddy currents in a metallic trip ( 1 ) brought into the vicinity of the proximity switch, which eddy currents generate a voltage-inducing eddy current field in the first receiving coil (E 1 ) of the receiving coil arrangement, the first coil (E 1 ) and a second coil (E 2 ) of the receiving coil arrangement being disposed and connected in such a way that the exciting field generates a differential voltage ( 3 ) in the receiving coil arrangement, and wherein the proximity switch further comprises a pair of compensating coils including the second coil (E 2 ) of the receiving coil arrangement and a compensating coil (S 2 ) connected in series with the first transmitting coil (S 1 ), the pair of compensating coils being disposed in such a way that they are virtually unable to be influenced by the eddy current field.