Abstract: In a synchronous machine starting device, an AC voltage detection unit detects AC voltage supplied to an armature of a synchronous machine through an electric power line from a power conversion unit. The AC voltage detection unit has a first output end and a second output end isolated from the electric power line, transforms AC voltage supplied through the electric power line at a first ratio to output the transformed voltage from the first output end, and transforms AC voltage supplied through the electric power line at a second ratio and then limits the transformed voltage to a prescribed positive voltage value or lower and a prescribed negative voltage value or higher for output from the second output end. Then, a detected voltage selection unit selects one of the voltage received from the first output end and the voltage received from the second output end, and outputs the selected one to a rotor position detection unit.

Abstract: Method and systems for testing an electric motor are provided. A switching circuit coupled to the motor is operated in a first mode causing current to flow through the motor such that the motor is actuated with near zero torque. A magnitude of the current is repeatedly adjusted between first and second values. The current flow through the motor is monitored.

Abstract: A piezoelectric actuator comprises a co-fired stack of piezoelectric elements formed from a piezoelectric material and a plurality of positive internal electrodes interdigitated with a plurality of negative internal electrodes throughout the stack to define active regions of the piezoelectric material which are responsive to a voltage applied across the internal electrodes, in use. An external positive electrode connects with the positive internal electrodes and an external negative electrode connects with the negative internal electrodes. The actuator is characterized in that the stack further comprises means for deliberately creating artificial cracks within the stack at a location at which the artificial cracks do not give rise to a short circuit between the internal electrodes but serve to relieve stresses within the piezoelectric material.

Abstract: A system for controlling a motorized track light system constrained to travel along a track has a control unit coupled to a motor that causes the track light system to move along the track, a plurality of stop sensors strategically disposed along the track, a sensor activation device located on the track light system, the sensor activation device positioned to interface with the stop sensors, and a light sensor for detecting ambient light of a preset level. The system detects a preset level of ambient light, initiating power to the motor of the track light system, moving the lights along the track until the activation device interfaces with a first of the plurality of stop sensors, stopping movement of the track light system along the track for a preset period of time, and at the end of the preset time period, the electrical power is restored to the motor moving the track light assembly along the track to the next of the plurality of stop sensors.

Abstract: A fan system circuit module including a stable voltage input terminal for receiving a stable voltage, an operation unit electrically connected to the stable voltage input terminal and a drive chip. The operation unit includes a first resistor, a second resistor, a first capacitor and a third resistor. After powered on at the stable voltage, the operation unit generates an operation signal for the drive chip to decrease drive current value of the fan. In case that a lock of the fan takes place, the drive chip can effectively decrease the block current. The circuit module has soft-start function and provides block current protection effect so as to avoid malfunctioning of the fan system due to too great start current of the fan and avoid burnout of the fan due to high rise of temperature.

Abstract: There is provided a motor. The motor may include a rotor case including a driving magnet formed on an inner circumferential surface thereof and providing a driving force by interacting with a coil of a stator, a low-speed control magnet formed on an outer circumferential surface of the rotor case and generating a frequency allowing for low-speed rotation enabling label printing as the rotor case rotates at a low speed; and a sensing part sensing an analog signal generated from the low-speed control magnet.

Abstract: In order to automatically detect a mechanically commutated DC motor, it is provided to acquire an electrical engine size, to determine current ripples in the engine size, to evaluate the amplitude, the duration and/or time position of the detected current ripples and to compare to known ripple patterns, and to choose from a known key data table a number of key data assigned to a certain engine type, when the amplitude, during and/or time position of the detected current ripples correspond to a ripple pattern, which is assigned to the engine type.

Abstract: Presented is a method for controlling a roller shade having a roller tube windingly receiving a flexible shade material. The method includes providing a motor that rotates the roller tube to move the flexible shade material between a first position and a second position. The method further includes capturing, with an optical sensor, an image frame at a plurality of linear positions along the flexible shade material as the flexible shade material moves from the first position to the second position. The method further includes controlling the reversible motor to move the flexible shade material from the first position to the second position in response to position information obtained from the captured image frames using a variable linear velocity profile so that the flexible shade material moves from the first position to the second position at a variable linear velocity.

Abstract: An electrically commuted reversible synchronous motor is activated in a calibration journey using an externally forced rotating field, during which an electrical angle of a rotating field and a mechanical angle of the rotor are measured simultaneously at a reference position by an external sensor. These items are stored associated with one another as a measurement series of value pairs. The electrical angle of the rotating field and the mechanical angle of the rotor are also detected simultaneously after direction reversal of the rotating field. These are stored as a second measurement series of value pairs. The angle difference between the electrical angle and the mechanical angle are calculated from value pairs of both measurement series. The correction value for taking the actual incorrect angle into consideration is calculated from the two angle differences by averaging.

Abstract: A control system for an electric machine, the control system including a position sensor and a drive controller. The drive controller generates one or more control signals for exciting a winding of the electric machine in response to edges of a signal output by the position sensor. The times at which the control signals are generated by the drive controller are corrected by a position-sensor offset that is fixed over an operating speed range of the electric machine.

Abstract: An apparatus for controlling a stepper motor comprises a driver circuit and a brake circuit each having a motor controller device. The driver circuit, brake circuit and motor are connected in parallel. The driver circuit receives an enabling signal and outputs driver current to the motor accordingly. The brake circuit includes a logic circuit which receives the enabling signal, a brake input signal, and a power supply status signal, and outputs a brake logic signal. The brake circuit motor controller device is coupled to the logic circuit. This motor controller device receives an output of the brake logic circuit and outputs braking current to the motor in accordance therewith. The braking circuit is effective to prevent movement of the motor shaft in accordance with output of the braking current. The motor controller devices are substantially identical. The apparatus is effective to control the motor while avoiding generation of RF noise.

Abstract: A rechargeable electric power tool includes a motor driven by a secondary battery, a switching element for regulating power distribution to the motor, a motor control unit for controlling rotation of the motor through the switching element, a lead wire for supplying a drive current to the motor therethrough and a trigger switch changed over by a user for turning on or off the drive current supplied to the motor through the lead wire. In the rechargeable electric power tool, upon changeover of the trigger switch, a microcomputer determines a magnitude relation between a detected temperature outputted from a first thermistor and a first temperature threshold value. If the detected temperature is determined to be greater than the first temperature threshold value, the microcomputer is set in a limited operation mode in which a revolution number of the motor is limited to a predetermined value or less.

Abstract: A differential amplifier detects a coil current Is at the time of steady rotation of a synchronous motor. An application voltage S0 at this time is detected from an output of an ATT circuit and so on. With the use of the coil current Is which is detected, the application voltage S0 at that time, and a predetermined scaling factor As, an induced current Ib is obtained based on Ib=As·S0?Is. The application voltage to the motor is controlled based on the induced current Ib which is obtained.

Abstract: An illustrative embodiment of a temperature-activated voltage generator includes a generator housing having a housing interior; a flexible, temperature-sensitive bimetallic element disposed in the housing interior; and a piezoelectric element carried by the generator housing. The bimetallic element is positional between a first position wherein the bimetallic element disengages the piezoelectric element and a second position wherein the bimetallic element engages the piezoelectric element. Electrical voltage output leads are electrically connected to the piezoelectric element. A voltage-generating method is also disclosed.

Abstract: A device and a method for determining the current position of a rotor, particularly the angle of rotation of the rotor, of an electric motor, wherein said device determines the current position of the rotor using the fluctuations of the armature current or the armature voltage of the electric motor. The fluctuations of the armature current or the armature voltage are separated from the fluctuations of the motor current or the motor voltage with the help of an amplifier unit dependent on a controllable offset value. The offset value is changed according to the motor current or the motor voltage. By virtue of the device and the method, the fluctuations of the armature current or the armature voltage can be separated from the fluctuations of the motor current or the motor voltage over the full measurement range of the motor current or the motor voltage.

Abstract: A system and method for controlling an AC motor drive includes a control system programmed with an energy algorithm configured to optimize operation of the motor drive. Specifically, the control system receives input of an initial voltage-frequency command to the AC motor drive, receives a real-time output of the AC motor drive generated according to the initial voltage-frequency command, and determines a real-time value of a motor parameter based on the real-time output of the AC motor drive. The control system also inputs a plurality of modified voltage-frequency commands to the AC motor drive, determines the real-time value of the motor parameter corresponding to each of the plurality of modified voltage-frequency commands, and identifies an optimal value of the motor parameter based on the real-time values of the motor parameter.

Abstract: Slow speed operation of a brushless DC (BLDC) motor is enhanced by gating off some of the PWM pulses in each commutation period. By doing so, longer PWM pulse widths may be used at PWM signal frequencies that are inaudible while still allowing desired slow speed operation of the BLDC motor. Centering the non-gated PWM pulses in each commutation period where peak back EMF occurs, further reduces losses and improves delivery of maximum torque from the BLDC motor.

Abstract: An apparatus operable in a wet environment includes a voltage doubler circuit including a pair of diodes, a pair of direct current switching elements connected between the respective diodes and a common point, a controller, an interface connected to the controller for receiving external status signals, and a switching arrangement responsive to signals from the controller to select the full power mode or a controlled power mode. In the controlled power mode, the switching elements are switched in a predetermined sequence such that only one of the switching elements conducts current during any one half cycle of the AC output voltage applied to the motor.

Abstract: An electric motor drive control apparatus includes a detection angle obtaining section that obtains the detection angle of the resolver; a correction information storage section that stores correction information for correcting the detection angle, in association with a modulation ratio that is a ratio of an effective value of a fundamental wave component of the AC voltage to the system voltage; and a detection angle correcting section that obtains the correction information from the correction information storage section, based on the modulation ratio at the time the detection angle obtaining section obtains the detection.

Abstract: The invention relates to a coupling unit (24) for transmitting high-frequency mechanical vibrations from a vibration generator (12) onto a tool (34). Said coupling unit comprises in input part (22) and an output part (30) that are interconnected via two identical vibration bars (26, 28), said bars being off-set from each other. The bars may have the shape of quadrants to provide the output movement in a direction that forms an angle of 90° with the direction of the input movement.