Abstract: A power switching device includes a power terminal connected to a power supply; a load terminal connected to a load; a power switch connected between said power terminal and said load terminal and arranged to be conductive in a first operating state; a power conductor connected between said power terminal and said load terminal in at least one state, wherein an electrical current through said power conductor changes in response to said power switch being turned off, thereby causing self-induction in said power conductor; and a control unit arranged to control said power switch in real-time on the basis of a real-time level of said voltage across said power conductor so as to turn off said power switch in a continuous or stepwise or pulsed manner to prevent a voltage across said power conductor from exceeding a maximum allowed level.

Abstract: A device for detecting an insulation fault of a direct voltage source that can induce electrocution, including: first and second input terminals for the voltage source; first and third resistive dipoles connected in series between an electric ground and the second input terminal, the first resistive dipole having a resistance at least ten times higher than that of the third dipole; a second resistive dipole and a switch connected in series between the first input terminal and the electric ground; and a detection circuit connected to the terminals of the third dipole, configured to alternately open and close the switch, measure the voltage at the terminals of the third dipole, and determine the amplitude of an insulation fault according to the measured voltages.

Abstract: A power tool system includes: a power tool including an AC motor; a portable battery pack; and a power supply device that converts a DC power supplied from the portable battery pack into an AC power to supply the AC power to the AC motor.

Abstract: In a control unit, a control part is operated by electric power from an ignition power supply, and controls operations of relays and inverters. A first end of a boosting part is electrically connected between at least one relay and a corresponding inverter. A second end of the boosting part is electrically connected to the control part. The boosting part boosts a voltage at the first end, and outputs the voltage boosted from the second end. An abnormality detecting portion detects an abnormality of the boosting part. When the abnormality detecting portion detects an abnormality of the boosting part, the control part controls the at least one relay to which the first end of the boosting part is connected to shut off a flow of electric power from a main power supply to the boosting part and to the inverter corresponding to the at least one relay.

Abstract: An electric power saving device for motor of pump jack apparatus. The electric power saving device preferably detects current and voltage generated from a motor of the pump jack during the up stroke and down stroke and preferably converts the real-time load torque obtained using an AC amplifier and voltage converter. The electric power saving device preferably minimizes the counter electromotive force (Back-EMF) and preferably reduces consumption of electrical energy by automatically reducing speed in a heavy-load during an up stroke, while automatically increasing speed in un-load, during a down stroke. This is preferably done by converting real-time load torque obtained by torque formula and through the output value according to load torque in order to minimize Back-EMF.

Abstract: An electric motor system includes a brushless direct-current motor, a driver circuit, a position sensor, and a control circuit. The motor has an output shaft for transmitting torque. The driver circuit supplies power to the motor according to a control signal input thereto. The position sensor measures an angular, rotational position of the motor shaft. The control circuit controls operation of the motor. The control circuit includes a position sensor terminal, a reference terminal, a differential calculator, a controller, and a gain adjuster. The position sensor terminal receives a feedback signal. The reference terminal receives a reference signal. The differential calculator generates an error signal representing a difference between the measured and targeted rotational positions. The controller generates the control signal based on the error signal through a combination of control actions. The gain adjuster is connected to the controller to adjust a gain of each control action.

Abstract: A drive circuit is provided for reducing conducted electromagnetic interference provided by a power line to a motor controller. The drive circuit includes an EMI filter having first and second EMI filter input terminals, and first and second EMI filter output terminals. The first input terminal is configured to be coupled to a first AC line output and the second input terminal is configured to be coupled to a second AC line output. The drive circuit includes a rectifier portion having first and rectifier input terminals coupled to the first and second EMI output terminals, respectively. The drive circuit includes at least two series-coupled filter capacitors after the rectifier portion and a PFC choke coupled at a first end to one of the EMI filter output terminals and to one of the first and second rectifier input terminals, and at a second end between the series-coupled filter capacitors.

Abstract: A method for controlling a permanently excited synchronous motor, in particular a brushless direct-current motor, having a permanently magnetized rotor and a number of stationary Stator windings to which an alternating voltage of predetermined amplitude and frequency is applied, wherein the frequency of the alternating voltage is determined by the speed of the motor and a phase difference results between the alternating voltage and the alternating current for each Stator winding. Accordingly, current is applied to the Stator windings in such a way that between alternating voltage (UPhase) and alternating current (IPhase) arises a phase angle (?Target, ??Target), which is selected according to speed (?), motor inductance (L), and the power received by the motor.

Abstract: A system and method for determining rotor shaft position of high voltage permanent magnet AC synchronous machines using auxiliary windings utilizes a permanent magnet AC synchronous motor including a stator having a main set of coils and an auxiliary set of coils. A drive controller including a digital signal processor in communication with the motor utilizes a current and voltage measurements from the main and auxiliary coils to determine the position of the rotor shaft in a sensorless mode.

Abstract: A rotation detector provided in a motor unit according to an embodiment includes a first support and a second support, a pair of magnetic field generator, at least one magnetic field detector, and a first magnetic member and a second magnetic member. The pair of magnetic field generator is provided on the first support in a manner facing the second support, and has opposite polarities. The magnetic field detector is formed by winding a coil around a magnetic element whose magnetized direction changes in the longitudinal direction, and is provided on the second support in such a manner that a longitudinal-direction side of the magnetic element faces the first support. Each of the first magnetic member and the second magnetic member is made of a magnetic material, and covers a longitudinal-direction end of the magnetic field detector facing the first support.

Abstract: A position sensorless step-wise freewheeling control method for a switched reluctance motor having dual switched-mode power converters for each phase doesn't require any additional external hardware, any rotor-position sensor, or storage of flux linkage data of the motor. After the upper and lower tubes of the main switch are switched off, and the phase of the switched reluctance motor enters into a negative voltage forced freewheeling state, the phase current is detected. When the phase current falls to a preset threshold, one of the upper or lower tubes is switched on and the phase enters into a zero voltage natural freewheeling state. When the phase current reaches a peak value, the rotor position becomes the start position of the minimum phase inductance and the rotor position is used as the switch-on position of the main switch. The upper and lower tubes are then switched on.

Abstract: A motor controller is provided with integrated metering and data logger functions to measure, store and report information suitable to verify the controller's energy saving performance. The integrated functions in the controller can be used to establish an AC motor's baseline electrical power and energy profile and to monitor continuously the power and energy reduction performance of the controller without requiring a separate meter and logger.

Abstract: A motor control system includes a drive motor and a deck motor that are connected to a battery, an ECU, and a key switch. The key switch acquires that an operation unit has been turned on, and transmits a restart permission signal to the ECU. When SOC of the battery reaches or falls below a first threshold set in advance, the ECU performs a step of disabling all the motors, and when the restart permission signal is received, the ECU performs a step of executing a decelerated travelling mode where the disabled state of the drive motor is released and an allowed speed of the drive motor is reduced.

Abstract: A drive signal generating unit generates a drive signal used to alternately deliver a positive current and a negative current to a coil. The drive signal is such that nonconducting periods are set before and after a positive current conducting period and the nonconducting periods are set before and after a negative current conducting period. A driver unit generates the drive current in response to the drive signal generated by the drive signal generating unit and then supplies the drive current to the coil. The drive signal generating unit sets the width of a nonconducting period such that, after the drive start of the linear vibration motor, the width of a nonconducting period to be set before at least the first conducting period of the drive signal is shorter than the width of a nonconducting period to be set before each conducting period during steady operation of the linear vibration motor.

Abstract: A motor control device includes an energization pattern output portion and an inverter circuit. The energization pattern output portion cyclically outputs a plurality of energization patterns. The inverter circuit selectively connects respective coils provided in a motor to a rectifier circuit according to the output energization pattern. The energization pattern output portion delays the output timing of the energization pattern according to a rotation speed of the motor.

Abstract: Stepper motor winding current regulation methods and apparatus continuously and bi-directionally sense winding current to determine both the magnitude of the winding current and the slope of a waveform representing the winding current. The magnitude and slope information is used to more precisely control periods of current rise and characteristics of fast and slow current decay during pulse-width modulation (“PWM”) regulation cycles. Winding current rise and decay shaping is based upon the sensed magnitude of the winding current, the magnitude of the winding current regulation set-point ITRIP, whether the sensed winding current is greater than or less than ITRIP at a selected sampling time, whether the sensed winding current is increasing or decreasing when a waveform of the sensed winding current crosses over ITRIP, and whether or not the magnitude of ITRIP changes during a PWM cycle in response to a receipt of a subsequent DAC code.

Abstract: A controlling apparatus for an electric motor according to an embodiment includes a superposed component generator, an inverter, a current detector, and a magnetic pole position estimator. The superposed component generator generates, at a predetermined cycle, a superposed voltage reference of which vector is shifted by 90 degrees with respect to that of a superposed voltage reference previously generated, in a coordinate system that is set to a stator of the electric motor. The inverter outputs a driving voltage that is based on a driving voltage reference superposed with the superposed voltage reference to the electric motor. The current detector detects currents flowing into respective phases of the electric motor, and outputs the detected currents. The magnetic pole position estimator detects the magnetic pole position of the electric motor based on an amount of change in the detected currents at the predetermined cycle.

Abstract: A control device for rotary machine includes: a voltage instruction generation section for generating a voltage instruction; a voltage application section for applying voltage to a rotary machine based on the voltage instruction; a current detection section for detecting rotary machine current of the rotary machine; and an inductance calculation section for calculating an inductance of the rotary machine from the voltage instruction and the rotary machine current. The voltage instruction generation section generates voltage instructions of constant DC voltages. The voltage application section applies voltages to the rotary machine based on the voltage instructions. The inductance calculation section calculates the inductance from a voltage instruction for measurement arbitrarily selected from the voltage instructions, and the rotary machine currents detected by the current detection section before and after application of the voltage instruction for measurement.

Abstract: A motor control device includes an energization pattern output portion and an inverter circuit. The energization pattern output portion cyclically outputs a plurality of energization patterns. The inverter circuit selectively connects respective coils provided in a motor to a rectifier circuit according to the output energization pattern. The energization pattern output portion delays the output timing of the energization pattern according to a rotation speed of the motor.

Abstract: A blower motor assembly having a variable speed motor that is suitable for replacing a PSC motor in a residential HVAC (heating, ventilation, and air conditioning) system. The blower motor assembly includes a variable speed motor and motor controller; a first power input for receiving a plurality of AC power signals from a control device for use in determining an operating parameter for the motor; and a second power input for receiving AC power from an AC power source for powering the motor controller even when no AC power signals are received by the first power input.