ANALYTICAL CIRCUIT FOR A CURRENT SENSOR WORKING ON THE COMPENSATION PRINCIPLE, IN PARTICULAR FOR THE MEASUREMENT OF DIRECT AND ALTERNATING CURRENTS AND METHOD FOR OPERATION OF SAID CURRENT SENSOR

摘要

Signal processing according to the invention permits a complete digital implementation of the control electronics and thus a cost reduction due to complete integration in an ASIC. The magnetic field probe is, for example, supplied with a square wave voltage of determined frequency, by means of resistors, the probe signal is recorded by one or two comparators and the pulse width is digitally measured by counters. Furthermore the conventional analogue final stage for the compensation current is replaced by a PWM end stage with a series connected sigma-delta modulator. A synchronisation with a set synchronisation signal ( for example from the measured value processing) is possible.