EINRICHTUNG ZUR DEFEKTERKENNUNG BEI SENSOREN

摘要

In order to detect defects in a sensor 10 which produces an output signal 13 forming the actual value feedback signal 13 for a controller 14 and which is preferably a differential inductive displacement sensor, a comparison is made in unit 16 of the actual value 13 with the output of the controller 14, a fault being detected if the actual value of the sensor lies within a predetermined range (around the normal mid-range value) and the controller is at the same time at one of its stops during a predeterminably longer time. As shown the sensor comprises inductors L1, L2 and a movable element 11. The inductors are fed with phase- opposed square waves +U, -U and their mid-point is connected to evaluation circuit 12. The output 13 of the circuit 12 is thus dependent on the position of the element 11 and forms the feedback signal for the controller 14 coupled to the element 11 via drive 15. Comparison logic 16 receives the actual value 13 and the controller output signal. A fault signal is produced by the logic circuit as described above, and also if the value 13 lies outside an allowed range. <IMAGE>