Abstract: A dual-speed single-phase AC motor, including: a stator, including a stator core, and a coil winding, including a starting winding, a first main winding, and a second main winding, a rotor, and a starting circuit, including a rectifying and voltage-stabilizing circuit, a detecting circuit, a voltage comparison circuit, a first switching circuit, a second switching circuit, and a third switching circuit. The number of poles of the starting winding is the same as that of the first main winding. The number of poles of the first main winding is less than that of the second main winding.

Abstract: A PSC motor includes a stator core, a rotor arranged in a rotation relationship with respect to the stator core, a first to eighth winding coil sets wound around the stator core and a capacitor. The motor has two kinds of configurations for 4-pole and 6-pole operation modes, respectively. Both configurations comprise a primary winding and a secondary winding which is connected in series with the capacitor, and have two reversible operation directions. The configurations operate different sets of winding coils when operating in different directions.

Abstract: A controller for a motor driving apparatus switches a direction of electricity flowing through a first coil according to a first lead angle signal obtained based on a first magnetic pole detecting signal and a second magnetic pole detecting signal. The controller switches a direction of electricity flowing through a second coil according to a second lead angle signal obtained based on the first magnetic pole detecting signal and the second magnetic pole detecting signal. Thus, a motor driving apparatus can be configured such that the angle of the rotation center of the rotor with respect to two magnetically sensitive poles can freely be selected.

Abstract: A power converter circuit for providing maximum utilization of a DC bus voltage to a two-phase Permanent Magnet Synchronous Motor (PMSM) is disclosed. The circuit includes first, second, and third nodes, each node being the junction between series connected high and low side switches connected across a DC bus; a PMSM having first and second windings and a star point at which the first and second windings are coupled to each other, the first winding having a terminal connected to the first node, the second winding having a terminal connected to the second node, and the star point being connected to the third node; and a controller for performing a three-point Pulse Width Modulation (PWM) coupled to a gate of each switch.

Abstract: For a multiphase alternating current (AC) wound field synchronous machine (WFSM) that has a stator with a selected number of poles, the WFSM having an associated exciter and multiphase AC permanent magnet machine (PMM) directly coupled to the WFSM, a method of sensing the position of a rotor in the WFSM comprises the steps of: configuring a stator for the PMM to have a number of poles that is a sub-multiple of the selected number of WFSM stator poles; configuring a rotor for the PMM to have high saliency; applying multiphase AC power of a selected frequency to the PMM stator; detecting at least one set of stator harmonic currents of the multiphase AC power resulting from the rotor saliency; converting the detected PMM harmonic stator currents from their multiphase coordinates to ?? coordinates; rotating the converted PMM stator currents into a reference frame for at least one selected harmonic to generate ?? coordinate harmonic current vectors; and estimating the position of the WFSM rotor based on the values

Abstract: A variable reluctance electric power system which comprises an alternator and a motor having a rotor with longitudinal lobes and no windings, commutators, slip rings, magnets, or laminations. The alternator and the motor have stators which have conventional windings and laminations and a rotor which is polarized using a static field winding which surrounds but does not touch the rotor. The alternator and the motor may be coupled with current from the alternator driving the motor and solid state power devices controlling the frequency of the current to insure that the current from the alternator is always synchronized with the motor rotor.

Abstract: In order to control the position of a mobile body without using a position detector, a magnetic pole position of a rotor of a synchronous motor is estimated based on electrical quantities in relation to electric power supplied to the synchronous motor and then the mobile body position is estimated based on the estimated magnetic pole position.

Abstract: A synchronous machine control device includes a flux command generator, a magnetic flux estimator, a divider, a flux controller and ?- and ?-axis armature current controllers. The flux command generator produces a flux command from the synchronous machine turning speed. The magnetic flux estimator calculates the magnitude and phase of armature flux linkage from armature currents and field current taking into consideration magnetic fluxes produced by permanent magnets. The divider produces an armature current command by dividing a torque command by the armature flux linkage. The flux controller determines a field current command based on an error of the magnitude of the armature flux linkage from the flux command.

Abstract: The invention provides a method and apparatus for maintaining the force, or torque, delivered by a variable reluctance motor as the speed of the motor increases. The method comprises the steps of sensing the speed of the motor and varying the number of turns of the motor's phase coil based on the sensed speed. The apparatus includes a motor speed sensor for sensing the speed of the motor and an inductance switch for switching the number of turns of the phase coil from a first value to a second value based on the sensed speed. One embodiment of the invention includes an inductance compensation circuit to compensate for the change in load inductance when the number of turns of the phase coil is switched.

Abstract: A sinusoidal acceleration trajectory controller is used in positioning a transducer at high speed to minimize vibration and acoustic noise. The controller reduces vibration and acoustic noise without sacrifice of seeking time by using a sinusoidal waveform as the actuator input. This sinusoidal waveform is a function of target track position and the seeking terminal time. When the velocity of the read/write head on the transducer reaches a maximum velocity, the sinusoidal waveform becomes a segment sinusoidal waveform, including a zero value waveform between two half sinusoidal waveforms. The amplitude of the sinusoidal waveforms and the coast period are minimized to obtain the minimum harmonic content in the segment sinusoidal waveform.

Abstract: A high-speed constant-horsepower motor includes a rotor and a stator having a plurality of groups of windings which are separately driven. In one mode of operation, the polarity of the voltage applied to each winding is such that the windings behave as distinct electromagnets, each defining a separate magnetic pole. In another mode of operation, the polarity of voltage applied to some of the windings is reversed, such that pairs of adjacent windings behave as single electromagnets. In the latter mode, the effective number of magnetic poles is reduced by a factor of two. Thus, the effective number of magnetic poles of the motor can be varied electronically, even while the motor is operating. The invention makes it possible, in one example, to operate the motor as an eight-pole motor at low speeds, and as a four-pole motor at high speeds. The effective motor constants are changed appropriately from eight-pole to four-pole modes.

Abstract: Improvements are described in an electric motor that includes a rotor with permanent magnets and a stator with electromagnets, of the "release" type wherein current to a "last" electromagnet that a permanent magnet is moving away from, receives only enough current to "release" the permanent magnet from the electromagnet core, with the permanent magnet attracted to the core of the "next" electromagnet whose coil does not carry current. The amount of current to the "last" electromagnet varies with the angular distance of the permanent magnet moving away from the "last" electromagnet. The electromagnets and permanent magnets can be in a ratio of 3 to 2. The percent of total electromagnets which are energized during each complete rotation of the rotor, can be reduced to save electricity when only a small output torque is required.

Abstract: A circuit for changing the poles of a rotor of a synchronous machine having contact brushes in operative connection with first and second slip rings includes a switch for reversibly connecting the contact brushes to an electrical current source, reversible pole coils operatively connected to one of the slip rings and connected through a first diode to a circuit portion which is formed by irreversible pole coils, and by a second diode and a third diode, and which is operatively connected with the other of the slip rings, and a circuit branch including a fourth diode having a polarity reversed with respect to the polarities of the first, second and third diodes. One terminal of the fourth diode is connected between the reversible pole coils and the first diode and the other terminal of the fourth diode is connected between the irreversible pole coils and the second diode.

Abstract: A three-phase motor is wound with three spaced phase windings each having first and second multiple section windings. The second winding sections of each are connected in series. The first winding has one end of all three phases connected in common. The second winding has one end connected to the common intermediate connection of the first winding sections. The outer ends of the windings are connected to a two-speed switch having two different positions for alternate direct connection of the two windings to incoming phase lines. In one position, both sections are in circuit with the three oppposite ends of the one winding connected to each other to form a second common connection. In second position, the second windings is disconnected and the first winding sections are connected in series in a star circuit, with the current flow in the two sections of each winding reversed from the first speed connection.

Abstract: In order to obtain any number of poles in the ratio p.sub.1 : p.sub.2 = 3m : 2n in a pole changeable three phase winding having nine base winding branches and only six connecting points with a simple, symmetrical, low harmonic content winding, three equiphasal induced coil sides belonging to the same phase of the winding are arranged such that for a pole pair number p.sub.2 they are located in three respective slots appearing as vectors with the same direction in the p.sub.2 pole pair slot-vector star or, in the case of at least two coils being arranged in each slot layer, two of every three such equiphasal induced coils belonging to the same phase for a pole number p.sub.2 are accommodated in a common slot with the third in a second slot appearing as a vector with the same direction in the p.sub.2 -pole pair slot-vector star.