Band attenuation / rejection filter for electromagnetic radiation of brushed DC motor

摘要

The invention relates to a band attenuation/elimination filter for the electromagnetic emissions of a DC motor with brushes, comprising at least a first capacitive electrical impedance element (C1) and a second capacitive electrical impedance element (C2, C3), which elements are integrated into a coil electromagnetic compatibility (EMC) filter formed by at least a first reactive impedance element (L1) inserted between the positive motor power supply terminal and the positive terminal of the battery (+Bat) and a second reactive impedance element (L2) inserted between the negative motor power supply terminal and the earth of the vehicle (-Bat). According to the invention, the first capacitive electrical impedance element (C1) is connected in parallel between the positive terminal and the negative motor power supply terminal, and the second capacitive electrical impedance element (C2, C3) has a lower capacitance than that of the first capacitive impedance element (C1) and is connected in parallel between the positive terminal of the battery (+Bat) and the earth terminal of the motor (-Bat). The invention is suitable for equipment for windscreen wiper motors for any type of motor vehicle.