AN INDUCTIVE LOAD CONTROL CIRCUIT, A BRAKING SYSTEM FOR A VEHICLE AND A METHOD OF MEASURING CURRENT IN AN INDUCTIVE LOAD CONTROL CIRCUIT

摘要

A method (400) and circuit (300) for controlling current through an inductive load (301) such as an electromagnetic valve of a vehicle anti-lock braking system comprises first and second driver stages( 302, 305), controlled by PWM (pulse width modulation) signals, for providing, respectively, an actuation path (304) for valve current in an "on" phase and a recirculation path (306) for valve current in an "off" phase. A peak value of current flowing in the actuation path (304) at the end of an "on" phase is compared with a peak value of current flowing in the recirculation path at the start of the "off phase in order to detect any malfunction of the circuit. The invention has the advantage of being able to detect any malfunction at very low and very high PWM duty cycles.