Resolver for detecting rotation position on the basis of response current to pulse voltage

摘要

A pulse excitation circuit applies a constant voltage to windings, each of which is wound around a respective one of four magnetic poles of a resolver stator. In each of the respective windings, a voltage is generated corresponding to the rotation of the resolver rotor. From the generated voltage, it is possible to detect two flows of electrical currents which have different phases from each other. Values of the electrical currents after a lapse of time 2*Lav/r from the start of pulse excitation (Lay is an average inductance of the windings, while r is a DC resistance of a winding, including an electrical current detection resistance) are converted into two digital values. A micro computer calculates a rotation angle signal theta on the basis of the two digital values.