Inductive proximity switch

摘要

An inductive proximity switch has in front of its active surface a sensor field for a magnetic or permeable trigger, and an oscillator, the resonant circuit of which exhibits a pot-shaped ferrite shell core (1) which is preceded by a cylindrical rod magnet (3) with a pole axis aligned in the direction of the centre axis of the shell core and of approximately the same diameter as the shell core (1). For the switching distance to be further increased, the ferrite shell core (1) is located on its side (4) facing away from the rod magnet (3) centrally on a permeable plate (5) projecting far past the core (1). For triggering also to be possible through a ferromagnetic or ferritic wall (11), a magnet (9) polarised in the same direction as the rod magnet (3) is used as trigger. <IMAGE>