Switching circuit for function monitoring for vehicle wheel RPM measuring sensor

摘要

The circuit has a galvanic separation stage using capacitors (6,6') between the sensor leads (2,2'), from sensor (1), which are connected between earth and the supply potential via voltage divider (5,5'). A comparator (7) is coupled to an evaluation device (10) on the output side. A switch allows the sensor leads on the sensor side of the galvanic decoupling stage to be connected to earth through resistances (4,4') for a timed duration. The evaluation stage compares the signals provided by the sensor for both positions of the switch.