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

A rotation position detection apparatus, comprising:

• a stator including a plurality of magnetic poles which are wound with a wire so as to constitute windings, and fixedly positioned on a circumference of the stator having a given interval between each other;
• a rotor having a shape so as to change a gap between the magnetic poles and the rotor in response to rotation of a rotor shaft;
• an excitation circuit for exciting the magnetic poles by supplying a constant pulse voltage to the windings for a pulse duration which is sufficiently short compared to a rotation cycle of the rotor shaft;
• an electrical current detection circuit for detecting electrical currents flowing within respective windings of the plurality of magnetic poles after a lapse of a predetermined time from a start of supplying the constant pulse voltage to the windings, with the windings remaining supplied with the voltage;
• and
• a rotation position calculation circuit for calculating a rotation position of the rotor on the basis of the electrical currents respectively detected.