Electronic switching device and circuits with a plurality of such

Abstract

An electronic proximity switching device with a proximity indicator and with an electronic switch which can be controlled by the proximity indicator. A plurality of these switching devices can be series connected without an unacceptable voltage drop occurring on the series connection when the switching devices are conductive, by the electronic switch of each switching device being connected to one input (2) of an AND element (3), another input (4) of the AND element (3) representing a control input (5) of the switching device, the output (6) of the AND element (3) representing the output (7) of the switching device, and load current flowing via the AND element (3) in the conductive state of the switching device. In other words there is AND element (3) in addition to an inductive proximity switch (1). A circuit for monitoring of the state of a system, for example, a fault state in an aerial railway or chairlift system, is provided with a plurality of switching devices (10), and with a control and evaluation unit (11), the switching devices (10) being series connected to one another and to the control and evaluation unit (11). When a fault state of the system is detected by the series connection of all switching devices (10), the fault can be located by interrogation of the switching devices with respect to their state (make or break contact state).