Abstract: The drive control circuit for an electric motor is provided. The drive control circuit includes: an original drive signal generator that generates an original drive signal; an excitation interval setter that is able, for each half cycle of respective length ? in each 2? excitation cycle of the original drive signal, to arbitrarily set excitation intervals during which to excite coils of the electric motor to any one of a plurality of intervals which include at least either one of a symmetrical interval centered on a center of each half-cycle and an unsymmetrical interval; and a drive signal shaping circuit that generates a drive signal for driving the electric motor, by validating the original drive signal during the excitation intervals and invalidating the original drive signal during non-excitation intervals other than the excitation interval.

Abstract: A brushless motor includes: a permanent magnet; a driving coil moving relative to the permanent magnet; a sensor coil disposed to the permanent magnet so as to generate a sensor coil induced voltage having a same phase of a driving coil induced voltage generated in the driving coil; and a driving circuit applying a driving voltage to the driving coil, the driving voltage having a same phase of the sensor coil induced voltage generated in the sensor coil.

Abstract: The drive control circuit for an electric motor is provided. The drive control circuit includes: an original drive signal generator that generates an original drive signal; an excitation interval setter that is able, for each half cycle of respective length ? in each 2? excitation cycle of the original drive signal, to arbitrarily set excitation intervals during which to excite coils of the electric motor to any one of a plurality of intervals which include at least either one of a symmetrical interval centered on a center of each half-cycle and an unsymmetrical interval; and a drive signal shaping circuit that generates a drive signal for driving the electric motor, by validating the original drive signal during the excitation intervals and invalidating the original drive signal during non-excitation intervals other than the excitation interval.

Abstract: The brushless motor has a first and second drive member. The first drive member is equipped with M phase coil groups each having N electromagnetic coils where M is an integer of 1 or greater and N is an integer of 1 or greater. The second drive member has a plurality of permanent magnets, and is able to move relative to the first drive member. The first drive member has 2 (M×N) magnetic body cores. Each phase electromagnetic coil is coiled on a periodically selected magnetic body core at a ratio of 1 to 2M from among the arrangement of 2 (M×N) magnetic body cores.