Abstract: An electric motor system is described. The electric motor system includes a drive circuit configured to supply variable frequency current and a contactor configured to supply line frequency current, wherein the drive circuit includes a three-phase inverter and an H-bridge including two phases of the inverter. The electric motor system also includes an electric motor and a controller. The controller is configured to control the inverter to supply variable frequency current to the electric motor over a first duration and determine to control the drive circuit to transition from supplying variable frequency current to supplying line frequency current. The controller is also configured to determine a polarity of a sensed alternating current (AC) voltage, disable at least two switches of the H-bridge, and control the contactor to close, thereby preventing the contactor and the inverter from energizing the electric motor at the same time once the contactor is closed.

Abstract: An HVAC system including a multi-capacity compressor, and a control system for the multi-capacity compressor are described herein. The control system includes an AC line voltage source, a variable-voltage variable-frequency drive, and a processor. The AC line voltage source is configured to operate the multi-capacity compressor. The variable-voltage variable-frequency drive is coupled to the AC line voltage source and is configured to operate the multi-capacity compressor at a variable speed. The processor is coupled to the AC line voltage source and the variable-voltage variable-frequency drive, and is configured to selectively couple the AC line voltage source and the variable-voltage variable-frequency drive to the multi-capacity compressor to operate the multi-capacity compressor. The processor is further configured to transmit a capacity control signal to the multi-capacity compressor.

Abstract: A motor driving circuit, an application device, and a motor braking method are provided. The driving circuit includes an inverter, a braking unit, and a MCU. The inverter is configured to drive a motor. The braking unit includes a sampling circuit, a discharge circuit, and a switch group. The MCU is connected to the sampling circuit, the discharge circuit, and the switch group, and is configured to control the sampling circuit to detect a voltage across the inverter and obtain a detected value when receiving the emergency signal, compare the detected value to a preset voltage or a preset voltage range, and transmit a control signal to activate the discharge circuit when the detected value is greater than the preset voltage or exceeds the preset voltage range.

Abstract: A kitchen appliance has a base, a driven mechanism rotatable relative to the base, and an electric motor with a stator and a rotor for driving the driven mechanism. The stator comprises a stator core with two primary stator poles with stator windings wound there on and two auxiliary stator poles. The stator windings are configured in such a way that primary magnetic poles with the same polarity are formed at the primary poles and induced magnetic poles with the same polarity which is opposite to the polarity of the primary magnetic poles are formed at the auxiliary poles when the motor is electrified.

Abstract: Provided is a control apparatus of a vibration-type actuator for generating an elliptical motion of contact portions by a common alternating current signal including a frequency determining unit for setting a frequency of the alternating current signal. The frequency determining unit sets the frequency of the alternating current signal for changing an ellipticity of the elliptical motion, within a frequency range such that ellipticity changing frequency ranges set for the vibrators are overlapped, and the ellipticity changing frequency ranges are set for the vibrators as frequency ranges between an upper limit and a lower limit, such that the lower limit is a maximum resonant frequency at a time of changing the ellipticity, and the upper limit is larger than the lower limit and is a maximum frequency for the relative movement of the driving member.

Abstract: An electromagnetic pump has a frequency converter circuit for driving the electromagnetic pump, wherein the frequency converter circuit comprises an oscillator circuit, a bistable circuit and a push-pull circuit. The oscillator circuit oscillates to transform DC into a single-phase oscillating signal. The bistable circuit splits the single-phase oscillating signal into a N-phase stimulus signal and a S-phase stimulus signal. The push-pull circuit amplifies and transports the N-phase stimulus signal and the S-phase stimulus signal to the electromagnetic pump to make the swing arms of the electromagnetic pump swinging effectively, wherein the swing speed, the swing frequency and the swing amplitude of the swing arms vary with the change of the oscillation frequency of the oscillator circuit.

Abstract: The discharge control device for a power conversion system performs discharge control to discharge a capacitor parallel-connected to the input side of the power conversion system including a plurality of pairs of high-side and low-side switching elements connected in series and each controlled by a drive unit, by turning on the high-side and low-side switching elements of one of the pairs at the same time. At this time, the discharge control device inhibits an ON command from being inputted to the drive units for the high-side and low side switching elements of the other pairs.

Abstract: A discharge control device in an electric power conversion system mounted to a motor vehicle turns off a relay in order to instruct an electric power conversion circuit to supply a reactive current into a motor generator, and thereby to decrease a capacitor voltage to a diagnostic voltage. After this process, the discharge control device outputs an emergency discharging instruction signal dis in order to turn on both power switching elements at high voltage side and a low voltage side in the electric power conversion circuit. This makes a short circuit between the electrodes of the capacitor in order to discharge the capacitor, and executes a discharging control to detect whether or not an emergency discharging control is correctly executed and completed. The discharge control device detects whether or not the electric power stored in the capacitor is discharged on the basis of the voltage of a voltage sensor.

Abstract: The drive system for a personal care appliance, such as a toothbrush, includes a first opposing pair of permanent magnet assemblies positioned longitudinally along the length of the internal surface of a cylindrical appliance housing, each first permanent magnet assembly having one portion with a north polarity and the other portion a south polarity, and a second pair of permanent magnet assemblies which are orthogonal to the first pair of permanent magnet assemblies, one second permanent magnet assembly having a plurality of abutting first parts along the length thereof, the parts alternating between a north polarity and a south polarity, the other second permanent magnet assembly having similar parts with reversed polarity. First and second armatures are mounted on, or a portion thereof forms, a spindle element which extends along the length of and outward from the cylindrical housing.

Abstract: A driving apparatus of a motor capable of operating a motor of a reciprocating compressor stably by using a simple power voltage control unit. The apparatus includes a power voltage control unit for maintaining a power voltage supplied from a power supply unit as a certain value when a motor is operated, outputting the certain power voltage or cutting off the power voltage after a certain time has passed; and a capacitor for applying the power voltage supplied from the power supply unit to the motor when the power voltage control unit cuts off the power voltage.

Abstract: The present invention relates to a vibration type actuator apparatus, and is aimed to provide an apparatus capable of determining a phase with which a driving voltage is applied to a piezo-electric member particularly relative to a phase of vibration displacement of a vibration member, shifting to a high-speed driving state in a short time, and abruptly stopping.

Abstract: An automatically controlled DC power supply output circuit includes an isolation diode connected in series between the power supply and the load, a terminal voltage detection circuit connected in parallel between the power supply and the load on the load side of the isolation diode, and a shunt resistor connected in parallel between the power supply and load on the power supply side of the isolation diode. A control element such as a switch or variable impedance is connected in series with the shunt resistor to cause the shunt resistor to shunt current from the power supply when the terminal voltage detection circuit detects that the terminal voltage exceeds a predetermined threshold, for example due to stored voltage in case the load is a battery, secondary cell, or capacitor, or due to counter EMF generated by the load in case the load is a DC motor, thereby reducing the power supply output voltage to compensate for the detected increase in terminal voltage.

Abstract: A circuit and method for providing drive currents to a polyphase dc motor are presented. The circuit (40) includes a circuit for generating a user-defined waveform first. signal in synchronism with a reference frequency signal. A reference frequency signal generator (62) generates pulses of a second signal at a reference frequency. A commutation circuit (56) combines segments of the first and second signals, and a circuit (64) is provided for applying the combined sinusoidal/trapezoidal waveforms to coils of the polyphase dc motor in a commutative sequence. Preferably, the user-defined waveform, when combined with the second signal, has approximately a sinusoidal/trapezoidal waveform.

Abstract: An electronic circuit and software control methodology tracks motor position in a motor drive system. High power consumption position transducers, such as inductive sensors or optical encoders, can be controlled in a variable active duty cycle mode to reduce power and yet maintain motor position information while the main power is off. A lower power battery backup circuit is implemented as a secondary power source, and is automatically brought in operation when the main power supply is disabled. A dedicated control circuit operates during AC power outages, and the circuit average power can be controlled to a minimal rate, based on the rate of change of motor position. The motor can be externally driven, up to a defined limit speed, without losing its actual position information.

Abstract: An electric motor with an electrodynamic braking means, where the same power controller is used in both motor operation and in braking. Therefore, the field current with the separately excited electric motor can be controlled or regulated by the power controller. It is also possible to preset a certain braking time. A measure of the braking current is obtained by sensing the voltage at a braking resistor, so the braking current can also be regulated on the basis of the field current.

Abstract: A motor drive system for driving a conventional single phase PSC motor from a two-phase power source which allows for convenient motor direction reversal. In one embodiment, the PSC motor is supplied from a three-phase inverter that is controlled to generate two-phase power. In another embodiment, the PSC motor is connectable through a double-pole double-throw switch to either a single phase source including a run capacitor or a two-phase inverter source.

Abstract: A motor drive system for driving a conventional single phase PSC motor from a two-phase power source. In one embodiment, the PSC motor is supplied from a three-phase inverter that is controlled to generate two-phase power. In another embodiment, the PSC motor is connectable through a double-pole double-throw switch to either a single phase source including a run capacitor or a two-phase inverter source.

Abstract: A reversible vibratory motor includes a driving member responsive to a first frequency of vibration for driving a driven member in a first direction, and responsive to a second frequency of vibration for driving the driven member in the opposite direction.

Abstract: A solenoid-actuated fluid pump having reciprocable armature operable by a magnetic circuit and with structure in the flux path at the upper and lower air gaps to substantially change the reluctance across the air gaps as the armature moves beyond a predetermined location. The armature has slots for passage of fluid therethrough and which have a C-shaped cross-section to minimize the air gaps.