29099results about "Dynamo-electric converter control" patented technology

In various embodiments, a surgical stapling instrument can comprise a plurality of magnetic elements configured to articulate an end effector of the surgical instrument. The surgical instrument can comprise at least one electromagnet which can be selectively activated, or polarized, to generate a magnetic field sufficient to motivate a second magnetic element, such as a permanent magnet and / or an iron core, for example, mounted to the end effector. In certain embodiments, a surgical stapling instrument can comprise a plurality of magnetic elements configured to open and / or close an end effector of the surgical instrument. In at least one embodiment, a surgical stapling instrument can comprise a plurality of magnetic elements configured to advance and / or retract a firing bar, cutting member, and / or staple sled within the surgical instrument in order to incise and / or staple tissue positioned within an end effector of the surgical instrument.

The steering angle of a vehicle is monitored using position sensors of an electric motor of an electric power assisted steering (EPAS) system. A position of the electric motor corresponding to the straight-ahead, center position of the steering system is stored in non-volatile memory during a steering calibration procedure, such as an end-of-line calibration in a vehicle assembly plant. Following power loss due to a dead battery, a steering angle zeroing procedure performed in a vehicle stability control (VSC) system generates a center position with enough accuracy to be within one electrical cycle of the motor. The pre-stored electric motor position is then used to determine the electrical cycle where the center position was located, and accurate monitoring of steering angle is resumed.

An apparatus for controlling the speed of an AC motor comprising a switch adapted to be coupled in parallel with power terminals for the AC motor; a capacitor coupled in series with the parallel combination of the switch and the motor; the capacitor adapted to provide an AC supply voltage from an AC source to the parallel circuit comprising the motor and the switch; and a control circuit for controlling the conduction time of the switch in order to vary the speed of the motor. The switch is preferably pulse-width modulated at a frequency twice the line frequency of the AC supply voltage, and the switch is turned on when the voltage across the AC motor is zero volts. The apparatus is operable to provide for continuously variable control of the motor speed while minimizing acoustic noise in the motor.

In a method for operating a power tool with an energy accumulator, in particular a rechargeable energy accumulator, which supplies power to an electric drive motor, a clock frequency is generated by an electronic unit, with which a gate of a MOSFET—which supplies operating voltage to the drive motor—is switched on with each cycle, and a switching-off of the MOSFET is carried out within one cycle using different signals, as a function of operating parameters.

The present invention relates to a method for control of a direct current motor in one or several fan units, each comprising a fan, which method comprises: generation of a control signal from a first control unit which is external in relation to the said fan unit; transmission of the said control signal to the said fan unit; reception of the transmitted control signal in the said fan unit; interpretation of the said control signal in a second control unit which is arranged in association with the said fan unit; and generation, in the said second control unit, of a supply signal for the said direct current motor, on the basis of the control signal generated by the first control unit and received in the fan unit and on the basis of a supply voltage. According to the invention, the method comprises transmission of the control signal together with the supply voltage over a shared communication link, with the control signal being superposed on the supply voltage. The invention also relates to an arrangement for such control. By means of the invention, improved control is obtained of a motor that can be utilized in a ventilated seat in a vehicle.

A controllable motor includes a rotor. A first stator winding set is operable, upon being energized, to generate and apply a first torque to the rotor. A second stator winding set independent of the first stator winding set is operable, upon being energized, to generate and apply a second torque to the rotor. A motor control is coupled to the first and second stator winding sets. The motor control is operable to selectively energize one of the first or second stator winding sets to thereby generate and apply one of the first or second torques to the rotor, and simultaneously energize both the first and second stator winding sets to thereby generate and apply a third torque greater than the first or the second torque.

A method of controlling a motorized window treatment provides for continued operation of the motorized window treatment during an overload or low-line condition. The motorized window treatment is driven by an electronic drive unit having a motor, a motor drive circuit, and a controller. The controller controls the motor drive circuit to drive the motor with a pulse-width modulated signal generated from a bus voltage. The controller is operable to monitor the magnitude of the bus voltage. If the bus voltage drops below a first voltage threshold, the controller stops the motor or reduces the duty cycle of the pulse-width modulated signal to allow the bus voltage to increase to an acceptable magnitude. When the bus voltage rises above a second voltage threshold, the controller begins driving the motor normally once again. During an overload or low-line condition, the controller is prevented from resetting, while driving the motor with minimal interruption to the movement of the motorized window treatment.

An electric wheeled apparatus comprises a main body, at least one wheel supported by the main body in a rotatable manner; an electric motor configured to apply torque to the at least one wheel, a battery interface configured to removably receive at least one battery pack which is originally designed as a power source of an electric power tool, and an electric circuit unit configured to electrically connect the at least one battery pack attached to the battery interface with the electric motor.

An H-bridge circuit is connected to a coil of the vibration motor that is to be driven. A comparator receives Hall signals indicating position information of a rotor of the vibration motor, and converts to an FG signal. A pulse width modulator generates a pulse-modulated pulse signal specifying energization time of the coil of the vibration motor. The pulse width modulator, in a first mode, after commencing start-up of the vibration motor, sets a duty ratio of the pulse signal to 100%, and after that, switches the duty ratio to a predetermined value in accordance with rotational frequency of the motor. In a second mode, the duty ratio of the pulse signal continues to be set to 100%. In a third mode, frequency and the duty ratio of the pulse signal are set based on a control signal of a pulse form inputted from outside. The control signal is used also in switching mode.

A motor driving method for driving a direct-current (DC) motor, designed for avoiding a reverse current induced by the Back Electromotive Force (BEMF), includes providing a driver circuit for driving the DC motor; comparing a signal level of a terminal of the DC motor and a predetermined voltage value to produce a comparing result; and controlling a specific lower gate switch to avoid the occurrence of a reverse current of the DC motor according to the comparing result.

An apparatus and method for controlling a hybrid motor, The hybrid motor, uses a permanent magnet instead of a field coil for a rotor, winds a coil round a stator in a multi-phase independent parallel manner, fixes a rectifying type encoder to the rotor and connects a sensor to a driving circuit. The apparatus comprises: an encoder attached to a rotor in cooperation with a pole sensor a speed input unit for generating a speed instruction signal a power switching circuit to generate motor driving signals; a drive module receiving the speed instruction signal and the sensor signal and outputting the speed instruction signal synchronized with the sensor signal as a driving motor signal; a power supply for applying a DC voltage to the power switching circuit; A logic power supply for converting the DC voltage into a logic voltage, and applying logic voltage to the drive module. The motor has n phases, n power switching circuits and n drive modules.

For the present invention, under various running speeds statuses, the voltage supplied to the DC brushless motor is relatively increased or decreased on the basis of the internal setting of the motor drive control device according to the increased or decreased rotational output speed, so as to prevent the shortcoming of too much variation of the input impedance caused by the inductive reactance of the winding accordingly changed when the speed of the DC brushless motor is changed, specifically, to prevent the shortcoming of unable producing required torque resulting from the increased inductive reactance caused by increasing the rotational speed which makes the current value become too low when input by the original working voltage.

An inverter device includes a plurality of switching circuits in which first switching elements including Si semiconductors and second switching element including WBG semiconductors having ON resistance smaller than that of the first switching elements and having switching speed higher than that of the first switching elements are connected in parallel. The inverter device includes a converting circuit that converts a direct-current voltage into a desired alternating-current voltage and a driving unit that generates a plurality of driving signals for respectively turning on and off the switching circuits. The inverter device includes, for each of the switching circuits, a gate circuit that, based on the driving signals, turns on the second switching element later than the first switching element and turns off the first switching element later than the second switching element.