Resolver/digital converter and control apparatus using the same

摘要

1. A motor-driven power steering apparatus, comprises a digital converting portion (2) that receives resolver signals from a resolver; an exciting signal generator (3) that generates an exciting signal and supplies said exciting signal to the resolver; a conversion trigger generator (4) that generates a conversion trigger according to said exciting signal; an A/D converter (11) that converts said resolver signals to digital values in response to said conversion trigger; a computing portion (12) that detects a failure by computing a value of electric current in a motor (8), and supplies said current value to said motor having its shaft connected to a controlled object (9) and the resolver; and a motor control apparatus for controlling the controlled obj ect (9) including a steering column and a steering mechanism, wherein a steering force is assisted according to a steering torque detected by a torque sensor (13), the assistance to said steering force is stopped when said steering torque detected by said torque sensor exceeds a predetermined threshold value.