Motor Position Sensor from Electricfil Automotive
October 10, 2010
The Electric Motor Position Sensor (EMPOS) from Electricfil Automotive, Miribel, France, is designed to provide rotor position in hybrid and electric vehicles. The eddy current device features a flat coil printed on a PCB with integrated processing electronics, measures rotor position on synchronous motors at speeds up to 20,000 rpm with measurement error <1° (electric), and draws 20 mA. A high-frequency AC current injected into the sensor's primary winding creates a magnetic field that then induces eddy currents in the target. The target then generates a magnetic field opposed to that of the primary winding; amplitude variations induced in the secondary winding can be used to determine rotor position with high accuracy.
Most Read Articles