US Patent 9966813 Electric motor and electric device equipped with same

Electric motor includes stator, rotor, a pair of bearings, outer-ring conducting part, and printed circuit board. Outer-ring conducting part electrically couples outer rings to each other that are included respectively in the pair of bearings. Printed circuit board includes drive circuit and an impedance element. Drive circuit includes ground line. Drive circuit controls an electric current that flows through stator winding. The impedance element is formed with at least not smaller than one pair of conductive patterns. One of the conductive patterns forming the impedance element is electrically coupled with outer-ring conducting part. The other of the conductive patterns forming the impedance element is electrically coupled with ground line included in drive circuit.