Patent ID: 8736259

Claim:
An electromagnetic induction type rotational position sensor comprising: a rotor substrate and a stator substrate placed to face each other, wherein the rotational position sensor is configured to detect rotational displacement of the rotor substrate, wherein the rotor substrate comprises an excitation coil of a meandering pattern on an outer circumferential side of the rotor substrate and a rotor-side rotary transformer on an inner circumferential side of the rotor substrate, wherein the stator substrate comprises n-pieces of detection coils of a meandering pattern on an outer circumferential side of the stator substrate and a stator-side rotary transformer on an inner circumferential side of the stator substrate, wherein n is an integer number of 3 or more, wherein the n-pieces of detection coils are arranged in a circumferential direction without overlapping each other, wherein the n-pieces of detection coils are displaced from each other by 360°/(2n) in electrical angle, and wherein the rotational position sensor includes a high frequency excitation circuit for applying a high frequency signal to the excitation coil through the stator-side rotary transformer and the rotor-side rotary transformer.