Abstract: The flattened brushless motor pump sucks liquid from suction port and discharges liquid from discharge port by rotating rotary shaft of flattened brushless motor flattened brushless motor has a stator unit having cores around which a plurality of armature coils are wound and terminals electrically connected to the armature coils, and being formed by molding the cores and the terminals with resin in a watertight manner a rotor unit having magnets disposed facing the cores via a gap, rotary shaft and a yoke fixed to the rotary shaft and holding the magnets, wherein an in-water bearing for sliding the rotary shaft by a water film.

Abstract: The rotation speed of a brushless motor is detected to generate a signal synchronizing with the rotation of the motor, and, on the basis of the synchronizing signal, a plurality of duty signals representing respectively different duty factors are generated. One of the plural duty signals is selected according to the detected rotation speed of the motor, and, on the basis of the selected duty signal, a corresponding exciting signal is supplied to the motor. The higher the detected rotation speed of the motor, the selected duty signal represents a larger duty factor.

Abstract: Disclosed is a permanent magnet which is suitable for use for a field system of an electric motor or the like and which is constituted by a single piece of magnetic material in which S and N poles are alternately continuously formed through non-magnetic flux regions or weak magnetic flux regions interposed therebetween, and further disclosed is a magnetization apparatus for magnetizing such a permanent magnet.

Abstract: A controller of a synchronous motor for stably controlling the synchronous motor from a low speed to a high speed. The controller includes a multi-phase synchronous motor, a multi-phase square wave oscillator circuit, a magnetic pole position detection unit for detecting a position of the magnetic pole of a rotor of the multi-phase synchronous motor, and a unit for calculating a detection period of the magnetic pole position of the rotor by the magnetic pole position detection unit. The controller further includes a unit for dividing multi-phase square waves for each phase generated from the multi-phase square wave oscillator circuit into a plurality of pulses for each period to produce the divided square pulses. The controller also includes an excitation current control unit for controlling the divided square pulses for each phase in accordance with the detection period to supply the pulses to stator coils of the motor.

Abstract: A brushless motor comprising: a rotor constituted by a permanent magnet having a plurality of circumferentially alternately equally magnetized N and S magnetic poles; a stator having a plurality of excitation coils equidistantly disposed around the rotor; a rotor position detecting member such as a magneto-sensitive element; and a printed circuit board having a commutation circuit for switching the electric current for the excitation coils based on a detection signal of the rotor position detecting member; wherein the number of the magnetic poles of the rotor is selected so that the number of the magnetic poles of the rotor located within an area between respective center lines of two adjacent excitation coils is an odd number not smaller than three. The width of each excitation coil is selected so that an angle .alpha. formed between lines connecting the circumferential opposite ends of each excitation coil commonly to a center of the rotor is made equal to an angle .beta.

Abstract: A control system for a motor is disclosed in which the position of a magnetic pole of the rotor of the motor is detected to produce a position signal, a multi-phase rectangular wave signal is produced by an oscillation circuit, and the frequency of the position signal is multiplied to obtain a multiple frequency signal. A stepwise wave changing stepwisely, with the same frequency as the multiple frequency, is generated. A signal corresponding to the position signal or a phase difference signal representing a phase difference between the multi-phase rectangular wave signal and the position signal is selectively applied as a drive signal to the motor by a drive signal switching circuit. A first signal is produced before the stepwise wave reaches a predetermined level and a second signal is produced when the predetermined level is reached.

Abstract: A synchronous motor control apparatus includes a polyphase synchronous motor, a frequency adjusting circuit responsive to the closing of a power supply switch to generate a frequency control signal for commanding to linearly increase an oscillation frequency from zero up to a given high frequency, a polyphase rectangular oscillation circuit whose oscillation frequency for polyphase rectangular waves is controlled in accordance with the frequency control signal, an energization phase adjusting circuit for generating a phase control signal in accordance with a signal related to the frequency control signal from the frequency adjusting circuit, an energization phase calculating circuit for controlling the phases of the polyphase rectangular oscillation frequency of the polyphase oscillation circuit, and a drive circuit for amplifying output polyphase rectangular signals of the energization phase calculating circuit and applying the same to a field winding of the motor.