Abstract: In a motor driving device, a first relay portion is connected between a power source and an inverter portion, a second relay portion is connected between the first relay portion and the inverter portion, and a motor relay portion is connected between the inverter portion and a winding group of a motor. Inverter pre-driver circuits respectively drive switching elements of the inverter portion. A first pre-driver circuit drives the first relay portion. A second pre-driver circuit drives the second relay portion and the motor relay portion. A controller controls driving of the inverter portion, the first relay portion, the second relay portion, and the motor relay portion, and detects a failure of the first relay portion, the second relay portion, and the motor relay portion.

Abstract: Starting device for electric motors provides a circuit including: a first branch connected at one end to a common point and at the opposite end to the start winding of the motor, whereon a starting capacitor, a resistor and fixed contacts of a relay are inserted in series respectively; a second branch in parallel with the first branch, connected at one end to the common point and at the opposite end to the main or run winding of the motors whereon the coil of the relay is inserted; a third branch in parallel with the branches and, connected at one end to the common point and at the opposite end to the start winding of the motor, whereon a run capacitor is installed, this common point being connected to the common connector of the motor via the power supply line.

Abstract: The present invention is intended to provide a winding arrangement of single star connection for a rotating electrical machine, capable of enhancing insulation performance in coils of the same phase. In such winding arrangement, a first coil U1 to a sixth coil U6 are formed respectively in coil arranging parts 1U to 6U. Next, a coil arranging part 7U is skipped and the seventh coil U7 is formed in a coil arranging part 8U. Then, a coil formed at the end of winding (eighth coil U8) is formed in the skipped coil arranging part 7U.

Abstract: Methods and systems for detecting a motor shorting relay failure. Exemplary embodiments include methods and systems for determining a motor shorting relay failure in a motor, the motor having first phase winding in a first leg of the motor, a second phase winding in a second leg of the motor, and a third phase winding in a third leg of the motor, the method including applying a first voltage signal to the first leg, applying a second voltage signal to the second leg, applying a test voltage to a test circuit electrically coupled to the third leg, measuring a third voltage signal in the third leg at a first predetermined time in response to the application of the first and second voltage signals and determining a motor shorting relay in the motor, based on the amplitude of the third voltage signal.

Abstract: An electric power steering apparatus for assisting the steering force of a steering member by an electric motor (18) driven by a driving circuit (13) connected to a power supply (P) by power connecting means (15a). The electric power steering apparatus comprising: means (12) for detecting a short-circuit failure on the driving circuit (13) and on a wiring connecting the driving circuit (13) and the electric motor (18); power off means (15) for turning off the power connecting means (15a) when a short circuit failure is detected; current detecting means (17) for detecting the value of a current flowing between the electric motor (18) and the driving circuit (13) after the power off means (15) turns off the power connecting means (15a); and current cutting means (Fa, Fb) for, when the current detecting means (17) detects a current value exceeding a predetermined value, irreversibly cutting off the current whose current value exceeds the predetermined.

Abstract: A coil winding number variable type motor for varying a cooling and heating capacity of a reciprocating motor includes: a plurality of coils separately wound and connected in series to each other so as to vary turn ratio among motor coils; a plurality of relays respectively connected between adjacent coils among the plurality of coils; and a relay controller for outputting and ON/OFF control signal for varying the winding number of the motor coil and controlling the relays according to a change in a load and a power supply voltage. The coil wound in the motor of the reciprocating compressor is divided into the main coil and the plurality of sub-coils and the winding number of the motor coil is varied by itself to control the stroke of the reciprocating compressor, thereby effectively coping with the change in the voltage or the load.

Abstract: A simple and economical mechanism providing automatic motor control. The mechanism includes a motor-rated relay directly connected to line voltage and the input terminal of a motor winding, and receiving a signal from a sensing device connected to line voltage and to a signal input on the relay. The relay and sensing device may be housed within a waterproof enclosure, or may be separately housed within a connection enclosure and a separate sensing device enclosure remote from the connection enclosure, the two enclosures being connected by a cable. The sensing device triggers the relay to control the supply of current to the motor winding.

Abstract: A motor start switch includes a temperature responsive resistor element and a cutout switch electrically connected in series with a start winding of an electric motor. The cutout switch is in thermal contact with the temperature responsive resistor element so that heat from the temperature responsive resistor element is transferred to a bimetal element in the cutout switch, causing the bimetal element to open the switch. Heat from a motor overload protector provides heat to maintain the bimetal element in an open position. As heat to operate the temperature responsive resistor element is obtained from existing circuit elements, the efficiency rating of the motor is unaffected.

Abstract: An alternating current induction motor having a tapped RUN winding for developing different levels of stator field excitation which induces rotational torque into a rotor having an output member that drives various levels of mechanical load. Instant motor loading is sensed as a change in power factor or subsynchronous slip speed and the level of RUN winding excitation, together with the resulting magnetic field strength, is immediately changed to compensate for the sensed load changes. The change in RUN winding excitation is brought about by having a RUN winding the full extent of which may be coupled with a.c. power to produce magnetic field strength and resulting output member torque at least sufficient to operate the motor under minimum load conditions, and at least one tapped portion of the RUN winding which may be alternatively coupled with the a.c.

Abstract: A water pump protector unit which includes electrical circuitry through which an electric motor is energized. The pump protector unit is primarily adapted for operation of a capacitor-start induction-run electric motor which operates a water pump. The electrical circuitry includes components for energization and deenergization of the start winding of a capacitor-start induction-run electric motor. The electrical circuitry senses the phase angle between the voltage and the current applied to the electric motor. When the phase angle indicates that the electric motor is operating without a load, the circuitry deenergizes the electric motor. Thus, the water pump is protected against damage which may occur when the water pump is operated without pumping water. Preferably, all of the components of the water pump protector unit are housed within a single cabinet.

Abstract: This disclosure relates to a circuit for controlling energization of a start winding of a single-phase motor connectable by power lines to an AC power supply. The circuit includes at least two triacs connected in back-to-back series relation and connected in series with the start winding. The circuit further comprises a reed switch including reed contacts and a reed coil. The gates of the two triacs are connected across the reed contacts, and the reed coil is connected in one of the power lines and receives the line current during energization of the motor.

Abstract: A D-C relay control is employed for a single phase induction motor for disconnecting the starting capacitors and/or starting windings from the main windings as the motor speed increases upon start up. D-C for the relay control is obtained from a rectifier coupled to the starting windings.

Abstract: A single phase motor is disclosed which comprises a stator assembly having a main winding, a start winding and an auxiliary winding wherein the start and auxiliary windings are connected in two alternative configurations during start and run conditions, respectively. During the start condition, the start and auxiliary windings are interconnected by a series connection which causes current to flow through the auxiliary winding in a reverse direction to the flow through the start winding so that there exists a bucking magnetic relationship between the fields in the start and auxiliary windings. During the run condition of the motor, however, the start and auxiliary windings are interconnected by a second series electrical connection which causes the current to flow through the auxiliary winding in a direction opposite the first direction so as to cause the magnetic fields in the start and auxiliary windings to be in an aiding relationship thereby improving motor operating efficiency.

Abstract: The control relay of a phase converter for converting a three phase motor to one phase operation is operated by D-C power in order to prevent voltage fluctuations on single phase power lines from causing the starting capacitors or the motor from being destroyed. The D-C power is obtained from a rectifier having its input coupled to the secondary of a transformer. The primary of the transformer is adapted to be coupled to the windings of the motor.The phase converter is adapted to be used with a 230 volt or 460 volt motor.

Abstract: A dynamoelectric machine having a low A ratio during its starting mode and a high A ratio during its running mode. During the starting mode of the dynamoelectric machine, an auxiliary winding serially connected in bucking relation with a phase winding is excited therewith across a main winding. Generally as the dynamoelectric machine is energized to a predetermined speed indicative of the occurrence of its running mode, the phase winding and the bucking auxiliary winding are electrically disassociated, and another auxiliary winding serially connected and arranged in additive relation with the phase winding is excited therewith across the main winding.A method of operating a dynamoelectric machine and a circuit are also disclosed.