Proximity switch for detecting a magnetic inductive field
OwnerGerno Soyck, Peter Dahlheimerinventors
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Abstract
An inductive proximity switch comprises a high-frequency oscillator, an oscillator coil and an oscillator core. An analyzing circuit detects the inclination amplitude depending on the degree of core saturation. The analyzing circuit triggers a switching process when a certain threshold value of amplitude is reached. The core consists, for example, of ferrite. A yoke-like body is assigned to the core. The use of such a soft-magnetic material for the yoke-like body, allows the construction of smaller sensors with a higher sensitivity and a more cost-advantageous production. Their permeability curve in relation with one quadrant of the coordinate system is clearaly S-shaped.
Claims5
Inductive proximity switch comprising a high-frequency oscillator, wherein an oscillator coil is provided with an open core, saturation-sensitive to a magnetic field to be detected, in connection with an evaluation circuit, which detects the oscillation amplitude depending on the degree of the core saturation, and which, upon reaching of a certain amplitude value, triggers a switching process, wherein a foil-shaped anchor plate (4), made of a soft-magnetic metal alloy with a certain permeability, is coordinated to the open core (1) of the oscillator coil (2) under formation of an air gap (3), which anchor plate allows an oscillator current (I.sub.o) to rise in a defined way upon intensification of the magnetic field from the damped state of said high frequency oscillator (10) or, respectively, upon a weakening of this field allows in a defined way to drop again in a damp state.
Dependencies are inferred from the claim text.