Rotation angle detecting device and an electric motor provided with the rotation angle detecting device

A rotation angle detecting device for detecting a rotation angle of a rotating shaft rotatably installed in a fixed body, comprising:

• a rotating plate fixed to the rotating shaft;
• a base mounted on the fixed body so as to face the rotating plate;
• a cover fixed to the fixed body so as to spread over the rotating plate;
• a first sheet coil which is mounted on a facing surface of the base opposite the rotating plate and is provided with an excitation coil;
• a second sheet coil which is mounted on a facing surface of the rotating plate opposite the base and is provided with a detecting coil opposite the excitation coil;
• a third sheet coil which is mounted on another facing surface of the rotating plate opposite the cover and is provided with a primary coil of an output transformer connected to the detecting coil by a connection assembly passing through the rotating plate;
• and
• a fourth sheet coil which is mounted on a facing surface of the cover opposite the rotating plate and is provided with a secondary coil opposite the primary coil of the output transformer.