METHOD FOR DIAGNOSING A VARIABLE RELUCTANCE MAGNETIC DETECTION HEAD, AND DETECTION CIRCUIT

摘要

According to the invention, a variable reluctance magnetic detection head outputs an electric signal (Uin), and a rising edge of the electric signal is compared with a first threshold (Th) in order to switch from a first state (B0) to a second state (B1), and a falling edge is compared with a second threshold (Tb) that is lower than the first threshold (Th) in order to switch from the second state (B1) to the first state (B0). In a diagnosis step, the first threshold (Th) or the second threshold (Tb) are modified so as to become mutually closer, and a defective magnetic detection head is detected if the cyclic ratio of the second state (B1) is modified during the diagnosis step by a value greater than a predetermined diagnosis threshold relative to a reference level. The invention also relates to a circuit implementing said method.