Electrical device for onboard-electrical system of e.g. motor car to form conductive connection with external direct current sink, has external power supply pin electrically accessed from outside during starting stage of switch element

摘要

The device has a protecting device protecting an outer contact against reverse polarity. An electrical circuit detects polarity of voltage between an electrical contact region (7) and an electrical ground of an external direct current (DC) power source or sink (9). An external power supply pin (8) is electrically and outwardly insulated during a preset basic stage (11a) of a switch element (11). The element is switched into a starting stage during proper polarity of the voltage. The pin is electrically accessed from outside during the starting stage of the element.