| 摘要 |
PURPOSE:To suppress noise by arranging a sensor coil, printed on the opposite surface to the driving coil mounting surface of a printed board, with an electrical angle of 90 deg. with respect to the driving coil. CONSTITUTION:Sensor coils 10a-10f are printed on the opposite surface to driving coils 3a-3f mounted on a printed board 1. The sensor coils 10a-10f are arranged with an electrical angle of 90 deg. with respect to the driving coils 3a-3f. Opposing sensor coils 10a-10f are connected in series and three series coils are then connected in star. Upon rotation of a rotor 4, a sine wave signal is produced from the series coil. Upon turn OFF of the driving currents for the driving coils 3a-3f, noise inducing flux functions reversely in one half section and the other half section of the sensor coils 10a-10f. Consequently, voltages induced in the sensor coils 10a-10f by the noise inducing flux are canceled one another. |
