Abstract: A rotation-detecting apparatus includes the following: a rotor coil provided on a rotor; detection coils provided on stators; a control circuit that detects the relative rotational angle between the rotor and the stators by processing detection signals induced in the detection coils as a result of the rotor coil being excited by an excitation signal; and a communicating means for performing data communication with an external device. The control circuit in the rotation-detecting apparatus has functionality whereby a switch signal that turns on and off at preset rotational angles is outputted on the basis of the aforementioned detection signals. Also, the control circuit is designed such that the set rotational angles for the aforementioned switch signal can be changed by the external device via the abovementioned communicating means.

Abstract: A rotation detector includes the following: a rotor and stators comprising a rotor substrate and stator substrates, each of which is a multilayer substrate; a rotor coil provided on the rotor substrate; and detection coils provided on the stator substrates. The frequency of an excitation signal used by said rotation detector is set so as to be higher than a prescribed frequency that would be required if the rotor and the stators were each made of a magnetic material.

Abstract: A rotation detector includes the following: a rotor and stators comprising a rotor substrate and stator substrates, each of which is a multilayer substrate; a rotor coil provided on the rotor substrate; and detection coils provided on the stator substrates. The frequency of an excitation signal used by said rotation detector is set so as to be higher than a prescribed frequency that would be required if the rotor and the stators were each made of a magnetic material.

Abstract: A rotation-detecting apparatus includes the following: a rotor coil provided on a rotor; detection coils provided on stators; a control circuit that detects the relative rotational angle between the rotor and the stators by processing detection signals induced in the detection coils as a result of the rotor coil being excited by an excitation signal; and a communicating means for performing data communication with an external device. The control circuit in the rotation-detecting apparatus has functionality whereby a switch signal that turns on and off at preset rotational angles is outputted on the basis of the aforementioned detection signals. Also, the control circuit is designed such that the set rotational angles for the aforementioned switch signal can be changed by the external device via the abovementioned communicating means.