Abstract: A method for operating a synchronous motor wherein a magnetic field is generated by a first motor component in a predetermined orientation, the method including generating a relative movement between the first and a second motor component limited to a predetermined value, and determining a direction of the relative movement, wherein the generating and determining are repeated until a change in the direction of the relative movement occurs, wherein a magnetic field having a changed orientation with regard to a previously generated magnetic field is generated by the first motor component, and wherein the orientation of the magnetic field with the changed orientation is changed by a predetermined orientation section and depending on the determined direction of the relative movement. The invention encompasses an amplifier for operating a synchronous motor and a system including an amplifier and a synchronous motor.

Abstract: Regulating the speed of a two-phase switched reluctance machine (TPSRM) rotor includes selecting either a motoring mode or braking mode of operation for the TPSRM, regulating the rotor speed, when the motoring mode is selected, using a control signal cooperatively produced by a speed control feedback loop and a current control feedback loop; and regulating the rotor speed, when the braking mode is selected, using a control signal produced by the current control feedback loop without the cooperation of the speed control feedback loop. The speed control feedback loop uses an established speed control signal and a signal indicative of the rotor's speed to dynamically adjust a first parameter governing the control signal. The current control feedback loop uses an established current control signal and a signal indicative of the current flowing through a stator winding of the TPSRM to dynamically adjust a second parameter governing the control signal.

Abstract: A system and method of manufacturing an electric machine comprising a rotor and a stator, wherein the stator comprises a fractional-slot concentrated winding having two sets of terminals, wherein a first set of terminals configures the fractional-slot concentrated winding to have a first pole-number (P1), and wherein a second set of terminals configures the fractional-slot concentrated winding to have a second pole number (P2) different from the first pole-number (P1).

Abstract: A motor controller including a vector controller that controls a permanent magnet motor including a rotor being provided with a permanent magnet having a coercivity low enough to allow modification in amount of magnetization and that executes a vector control by detecting current flowing at the permanent magnet motor; a speed/position detector that detects a rotational speed and a rotational position of the permanent magnet motor; a magnetization controller that increases or decreases the magnetization of the permanent magnet depending on the rotational position of the permanent magnet motor through adjustment in status of the magnetization of the permanent magnet by way of armature counteraction; and a demagnetization detector that detects a decrease in the magnetization of the permanent magnet magnetized by the magnetization controller during operation of the permanent magnet motor.

Abstract: A method for controlling a multi-phase motor includes withholding energization of a first phase of the motor for a non-zero period when the first phase's dwell time begins. Energization of the first phase is activated upon the expiration of the non-zero period. Energization of the first phase is deactivated for the remainder of the dwell time at a deactivation time occurring before or at the expiration of the dwell time.

Abstract: Embodiments of a switched reluctance (SR) motor for use in a integrated vacuum system for a vehicle are disclosed. The SR motor may receive input voltage directly from an electrical storage device used to start up an engine of the vehicle. The SR motor may include an encoder that triggers an optical sensor to provide signals to a motor controller. The motor controller may energize stator poles based on the received signals. The encoder may be mechanically phase-advanced with respect to poles of the rotor to ensure proper start-up of the SR motor. Commutations of the motor may occur before a point of maximum inductance where the rotor and stator are aligned. In a preferred embodiment, the input voltage received by the SR motor is in a range of 9-16 Volts DC, a maximum drawn current is 36 amps, and the phase advance is between 9-11 degrees.

Abstract: To reduce the cogging torque of servomotors, electric power steering motors, and others, there is provided a permanent magnet motor comprising: a rotor 10 comprising a rotor yoke 11 and a plurality of permanent magnets (M1-M10); and a stator 20 comprising a stator yoke 22, salient magnetic poles 21, and armature windings 23, wherein at least one of the permanent magnets is disposed in an adjustment position that is displaced from a corresponding reference position in at least one of the circumferential, radial, and axial directions of the rotor yoke, and the plurality of permanent magnets excluding the permanent magnet disposed in the adjustment position is disposed in the reference positions, and wherein the adjustment position is set so that the permanent magnet motor in which at least one of the plurality of permanent magnets is disposed in the adjustment position has a smaller cogging torque than a permanent magnet motor in which all of the plurality of permanent magnets are disposed in the reference posi

Abstract: Methods and apparatus are provided for a limp home operational mode for an electric motor system. The method includes determining whether a resolver has failed. When the resolver has not failed, operation of the electric motor system uses resolver signals. When the resolver fails, operation of the electric motor system uses sensorless rotor position and rotor speed signals.

Abstract: A power factor correction system includes a rectifier that rectifies the voltage of an alternating current (ac) power source to produce a voltage waveform that transitions, in a half sinusoid, from a minimum amplitude to a maximum amplitude and back to the minimum amplitude twice in the period of the ac power source. A phase winding of a motor conveys current induced by the voltage waveform, and a regulator regulates the flow of the current conveyed by the phase winding for storage as energy in a storage component.

Abstract: A motor controller controlling a permanent magnet motor including a rotor provided with a plurality of low coercivity permanent magnets having a coercivity low enough to allow modification in amount of magnetization, the motor controller including a position detector including one or more position sensors to detect a rotational position of the rotor; an inverter circuit connected between a direct current voltage supply source and windings of the permanent magnet motor and configured by a plurality of semiconductor switching elements of multiple phases connected thereto; and a magnetization controller that magnetizes the plurality of low coercivity permanent magnets constituting the rotor by energizing the windings of the permanent magnet motor through the inverter circuit such that all of the low coercivity permanent magnets are magnetized to a uniform level of magnetization by energizing the windings twice at same timings specified based on a sensor signal outputted by the position sensor.

Abstract: Method for determining the angular position of the rotor of a mechanically commutated DC servo motor (5), which is arranged in the transverse branch of a bridge circuit, and the armature current of which is preset by an electromechanically activated switching device (28), —with a control and analysis unit (17) which analyzes the current ripple (3) present in the armature current (2) and attributable to the mechanical commutation, characterized in that—from each switch contact (6, 7) of the switching device (28), a contact-voltage feedback signal (9, 10) is fed back to the control and analysis device (17) by means of a feedback circuit (20), and in that the control and analysis unit (17), by using the at least one contact-voltage feedback signal (9, 10), determines a contact vibration time interval (4) and performs an estimate of current ripple (3) during this contact vibration time interval (4), during which an analysis of the current ripple due to contact vibrations which are caused by a switching process of

Abstract: An optical apparatus ensuring smooth driving control of an optical member is disclosed. The optical apparatus includes an optical member, a stepping motor configured to drive the optical member, a driving commander configured to generate driving pulses supplied to the stepping motor, a pulse count generator configured to count the driving pulses output from the driving commander, a position detector configured to detect a position of the optical member, and a pulse count presetter configured to replace, based on an output of the pulse count presetter and an output of the position detector, a pulse count output from the pulse count presetter with a pulse count corresponding to the output of the position detector.

Abstract: A full-pitch winding switched reluctance motor is provided. In this motor, one set of current components are estimated, which electromagnetically act on only one set of stator poles for one phase. Based on the estimated one set of current components, current components for respective three phases are controlled, resulting in accurate current control with no electromagnetic interactions with other phases. This current control allows a control circuit to be made compact, and a motor with effective field means can be provided.

Abstract: Methods and apparatus are provided for a controlling an electric motor that is at least partially disposed within a motor housing. The rotational speed and position of the electric motor are sensed, and a temperature of the electric motor is sensed. The sensor signals are converted to optical signals and are propagated in a fiber optic cable. The electric motor is controlled based, at least in part, on the propagated optical signals.

Abstract: A single controllable switch (509) drive system for regulating the speed of a two-phase switched reluctance machine (TPSRM) (700) rotor may include a speed control feedback loop (970) component that uses an established speed control signal and a signal indicative of the rotor's speed to dynamically adjust a first parameter. And a current control feedback loop (976) component that uses an established current control signal and a signal indicative of the current flowing through a stator winding (505,508) of the TPSRM to dynamically adjust a second parameter.

Abstract: A method for controlling starting of a motor is described, which is mainly applicable to estimate a possible initial position of a rotor of a motor by detecting a rotor rotation signal of the motor, and find out a most possible initial position of the rotor after making statistics. In the method for controlling the starting of the motor, a starting angle position region of the motor is calculated simply by using the rotor rotation signal of the motor, without additionally arranging a Hall sensor, so as to save a cost of a Hall device and an assembling cost. Furthermore, accuracy for estimating the starting position region can be increased according to an accuracy specification of products, thereby achieving a high flexibility.

Abstract: Electrical machine arrangements have advantages with regard to providing local electrical power and starting. Embedding such electrical machine arrangements in machinery such as gas turbine engines is advantageous in removing mechanical linkages and reducing aerodynamic drag. However, the components utilized must be able to withstand harsh environmental conditions and therefore the DC link capacitor used for smoothing of voltage fluctuations are limited to relatively low capacitance densities. Low density DC link capacitors require large sizes which render electrical machines less acceptable for embedded usage. By providing offset of electrical current in inductance elements such as stator windings and stator coils of electrical machines in dead periods of the cycle a reduction in DC link capacitor requirements is achieved reducing the size, weight and complexity of installing electrical machines in gas turbine engines.

Abstract: A brushless motor includes a two-phase winding stator having 4×n winding poles and auxiliary poles provided between the winding poles, and a rotor constituted by 6×n permanent magnet rotating poles having divided angle. The two-phase brushless motor can be driven by a control device for the two-phase motor which can transform electric power and rectify electronically. The two-phase brushless DC motor can increase a permeance coefficient of the rotor, improve the efficiency and the starting of the motor, and reduce torque ripple and noise thereof.

Abstract: Disclosed herein is a torque control method for a high-speed Switched Reluctance Motor (SRM), which controls a torque in the high-speed operation of a 2-phase SRM. In the torque control method for a high-speed SRM, a positive torque (T*mA) of an active phase (A phase) of the two phases of the SRM is compensated for based on a negative torque attributable to an inactive phase (B phase) of two phases during a compensation control enable interval (ENA) ranging from a time point at which the active phase (A phase) is turned on to a time point at which tail current of the inactive phase (B phase) remains. Accordingly, the present invention can remarkably reduce a torque ripple occurring in high-speed operation mode in consideration of the influence of a negative torque attributable to tail current.

Abstract: Disclosed herein is a method of controlling the current of a high-speed Switched Reluctance Motor (SRM) using an inverter circuit including a first switching element, a second switching element, a first diode, a second diode and a reactor, wherein the first switching element and the first diode, the second diode and the second switching element are connected to a bridge circuit, and one end of the reactor is connected to the junction of the first switching element and the first diode, and the remaining end of the reactor is connected to the junction of the second diode and the second switching element; and excitation mode, free-wheeling mode-1, the excitation mode, and free-wheeling mode-2 are sequentially performed in a unit period T, and, when the control is terminated, demagnetization is performed.

Abstract: An AC motor is provided. In the AC motor, there are M pieces (M is an integer of 3 or more) of stator pole groups SPG are arranged in a rotor axis direction, where each of the stator poles groups is composed of a plurality of stator poles which are for the same phase and arranged in a circumferential direction of the motor. Between the stator pole groups SPG, “M?1” pieces of annular windings WR are arranged which allow one-way current to flow therethrough. The windings WR are arranged such that the directions of current passing therethrough are reversed in turn in the rotor axis direction. The stator pole groups SPG are excited to generate magnetic fluxes ?G directed in a one way. The excited directions of the magnetic fluxes ?G are reversed in turn in the rotor axis direction.

Abstract: In an automatic transmission position control by a motor, it is determined whether the present instant belongs to a starting period, that is, the present instant is immediately after resetting of a control unit or application of power to it. If it is the starting period, an actual shift position that is detected from an output of an output shaft sensor for detecting a rotation position of a motor is set as an instructed shift position. With this measure, even if the control unit is reset for a certain reason while the vehicle is running, the instructed shift position is not changed in association with the resetting. This prevents trouble that the shift position is switched contrary to the intention of the driver, whereby the reliability of a position switching control can be increased.

Abstract: A reluctance machine includes a stator and a rotor. The stator and rotor have a same number of poles. The rotor is configured to rotate about an axis of rotation. Each stator pole is formed of a primary stator pole and an auxiliary stator pole. The auxiliary stator pole is axially aligned with the primary stator pole in the direction of the axis of rotation. Each rotor pole has a length extending in the direction of the axis of rotation sufficient to at least partially cover the primary stator pole and axially aligned auxiliary stator pole. The primary stator poles are actuated with an alternating magnetic field orientation, and the auxiliary stator poles are also actuated with an alternating magnetic field orientation. The field orientations for the primary and auxiliary stator poles are, however, opposite each other such that a primary stator pole its axially aligned auxiliary stator pole have opposite magnetic field orientations.

Abstract: A system and technique for measuring the mutual inductance in a switched reluctance machine (SRM). In a first example embodiment of the technique, a voltage pulse is applied to primary coil when the machine is stationery. By measuring current in the primary coil and measuring induced voltages in adjacent open circuited coils mutual inductance may be determined. In another example embodiment, a voltage pulse is applied to the primary coil when the machine is stationery. The secondary coil is allowed to freewheel current through the phase. By measuring time taken by the primary phase to reach a preset value, the mutual inductance for the known position of a rotor can be determined.

Abstract: A motor and a control unit therefor comprise: salient rotor poles and salient stator poles, which are arranged along circumferences of phases A, B and C with an even interval therebetween; magnetic paths for passing magnetic fluxes, the paths permitting the magnetic fluxes passing through the salient rotor and stator poles of each phase to return to the rotor side; and substantially looped windings arranged between the salient stator poles of individual phases and the magnetic paths for passing magnetic fluxes, wherein currents are supplied to the windings in synchronization with the rotational position of the rotor to thereby output torque. Since the structures of the stator, the rotor and the windings are simple, productivity is enhanced, whereby high quality, small size and low cost can be realized.

Abstract: A distributed electromechanical actuation system including multiple electromechanical actuators intended to operate together in a synchronous (or near synchronous) manner. Each individual actuator is powered by one or more induction motors or other appropriate motor such as a stepper motor. The induction motors are designed to have a very high pullout torque with very low slippage to the pull out point. The group of actuators is controlled from a single controller (e.g., an induction motor controller) that utilizes a Volts per Hertz type of open loop control where the bus voltage and frequency are controlled to assure that the motors always operate on the low slip side of the pull out point performance curve.

Abstract: Electric drive units comprising a common active part having a stator and a rotor, which has windings and/or permanent magnets for a drive function and an energy transmission function, enable the rotor winding that is provided for energy transmission to be used to allow position detection at a low additional cost. For this purpose, a power converter in the rotor, which provides the output of electrical energy for the energy transmission function, impresses an alternating voltage into the rotor winding, said voltage being detected in the stator and allowing the rotor position to be determined.

Abstract: The present invention provides a generator motor driving device that can promptly perform discharging of charges from the capacitor during a maintenance operation, and a capacitor discharge method to be implemented in the generator motor driving device. Power is supplied from the capacitor to the generator motor being driven by the engine, and the generator motor is driven, with the engine as a load. Rated constant current control is performed on the generator motor, and rated constant voltage control is performed on the booster, until the capacitor voltage decreases to a first voltage. After the capacitor voltage decreases to the first voltage, the rated constant current control is performed on the generator motor, and voltage control is performed on the booster to maintain a predetermined ratio between the capacitor voltage and the booster output voltage to be output to the driver, until the capacitor voltage decreases to a second voltage that is lower than the first voltage.

Abstract: A controller for a switched reluctance machine (SRM) generates current commands that reduce torque harmonics generated by the SRM. The controller monitors the phase currents and rotor position of the SRM to estimate torque generated by the SRM. The current command signal is modified based on the difference between the torque command and the estimated torque. A multiplier that varies with the monitored torque command is applied to the modified current command to provide a smooth phase-to-phase transition.

Abstract: A power system for a vehicle may comprise an electric machine attached to an engine of the vehicle. The electric machine may comprise only one stator core; a stator main winding wound on the one stator core; a stator exciter winding wound on the one stator core. The stator main winding and the stator exciter winding may be magnetically independent from one another even though magnetic-field-isolation material is not interposed between the stator main winding and the stator exciter winding.

Abstract: The present invention provides a superconductive rotating electric machine drive control system that has higher efficiency and is smaller size and lighter in weight than conventional systems, and also provides a superconductive rotating electric machine drive control method to be implemented in the superconductive rotating electric machine drive control system. By the superconductive rotating electric machine drive control system and the superconductive rotating electric machine drive control method in accordance with the present invention, a control operation is performed so that the field current If2 applied to the superconductive field winding of the synchronous rotating electric machine satisfies an equation for the field current If2 in accordance with the variation of the electric power exchanged between the synchronous rotating electric machine and the power unit.

Abstract: A system. The system includes a first module, a second module communicably connected to the first module, a third module communicably connected to the first module, and a fourth module communicably connected to the third module. The first module is configured for determining an angle. The angle is defined by a first rotating reference frame having an axis aligned with a permanent magnet flux of a permanent magnet motor, and a vector of a motor magnetizing flux of the permanent magnet motor. The second module is configured for defining a second rotating reference frame having an axis aligned with the vector, and for transforming a two-phase set of direct currents from the first rotating reference frame to the second rotating reference frame. The first and second rotating reference frames are synchronized. The third module is configured for generating a first direct current reference signal associated with the second rotating reference frame.

Abstract: An interface module is operable to download data from an electrical machine. The interface module includes a cable for transferring data, the cable having a first connector at a first end thereof, a circuit board having a programmable device electrically coupled in circuit to the cable, and a memory connected to the circuit board and configured to store data related to the operating characteristics of the electrical machine.

Abstract: An interface cord is operable to connect an external controller to an electrical machine. The interface cord includes a first connector having a first pin configuration, a cable coupled to the first connector, a second connector coupled to the cable and having a second pin configuration different from the first pin configuration, and a circuit board with a programmable electrically coupled in circuit between the first connector and the second connector.

Abstract: A switched reluctance motor includes an inner stator having a plurality of stator poles with coil windings, the inner stator having a plurality of stator phases, an outer rotor configured to rotate around the inner stator, the outer rotor having a plurality of rotor poles, at least one position sensor configured to detect a position of the outer rotor, and a DC supply configured to sequentially supply current to excite the stator phases.

Abstract: An interface cord is operable to connect an external controller to an electrical machine. The interface cord includes a first connector having a first pin configuration, a cable coupled to the first connector, a second connector coupled to the cable and having a second pin configuration different from the first pin configuration, and a circuit board with a programmable electrically coupled in circuit between the first connector and the second connector.

Abstract: Methods and apparatus are provided for deriving precision position and rate information for motors using relatively low precision analog sensors, and for implementing compensation techniques that overcome inherent sensor errors and rotor magnet flux tolerances.

Abstract: A switched reluctance machine having salient stator and rotor poles. Alternating ones of the stator poles having windings and the others having permanent magnets attached on their pole faces. The alternate stator pole windings are provided with polarities that are suitable for unidirectional and bidirectional current operation of the switched reluctance machine. The alternate poles with permanent magnets in the switched reluctance machines can have also concentric windings placed on them and excited with currents to further augment the flux linkages in the stator poles. The windings on the poles with permanent magnets can be excited from the same source as the windings on the poles without permanent magnets to enhance power output or provide power factor correction.

Abstract: A DC motor system includes a plurality of speed taps coupled to an AC source and a variable speed DC motor. A circuit determines which speed taps are coupled to the AC source, outputs corresponding logic signals, and isolates digital circuits from the AC source. A digital logic device accesses from memory a value corresponding to the upper limit speed of the variable speed DC motor, determines a commanded motor speed based at least in part on the logic signals and the upper limit speed value, and outputs a pulse width modulated signal having a duty cycle corresponding to the determined commanded motor speed. A driver receives the pulse width modulated signal and outputs a corresponding signal. The variable speed DC motor receives the driver output signal, and rotates a rotor at a speed corresponding to the pulse width modulated signal duty cycle.

Abstract: A flux switching electric motor (102) is disclosed. The motor comprises a rotor (104), a stator (106), field windings (124, 126) and armature windings (128, 130). #A microcontroller (134) controls supply of electrical current to the field and armature windings. A rotor position sensor includes a divider for (i) receiving an input signal dependent upon the rate of change of current in at least one field winding, (ii) receiving an input signal dependent upon the voltage across at least one armature winding, current through which causes at least part of the current in the field winding, and (iii) providing the microcontroller (134) with a control signal which is dependent upon the ratio of the input signals received by the divider.

Abstract: In an automatic transmission position control by a motor, it is determined whether the present instant belongs to a starting period, that is, the present instant is immediately after resetting of a control unit or application of power to it. If it is the starting period, an actual shift position that is detected from an output of an output shaft sensor for detecting a rotation position of a motor is set as an instructed shift position. With this measure, even if the control unit is reset for a certain reason while the vehicle is running, the instructed shift position is not changed in association with the resetting. This prevents trouble that the shift position is switched contrary to the intention of the driver, whereby the reliability of a position switching control can be increased.

Abstract: The present invention relates to a two-phase brushless DC motor which can increase a pemerance coefficient of a rotor to the maximum to thereby improve efficiency and starting feature of the motor, and to reduce torque ripple and noise thereof. The brushless motor of the present invention includes a two-phase winding stator having 4×n winding poles and auxiliary poles provided between the winding poles, and a rotor constituted by 6×n permanent magnet rotating poles having divided angle. Auxiliary poles between the stator poles can be provided. The two-phase brushless motor of the present invention can be driven by a control device for the two-phase motor which can transform electric power and rectify electronically.

Abstract: At an initial drive operation after turning on of an electric power source, an ECU sequentially changes each current exciting phase among multiple phases through one complete cycle at a predetermined time schedule, so that a rotational position of a rotor and the corresponding exciting phase coincide with each other at some timing during the initial drive operation, and thereby the rotor is rotated. The ECU counts the A-phase signal and the B-phase signal during the rotation of the rotor in the initial drive operation and learns a relationship among a count value of the A-phase signal and the B-phase signal, a rotational position of the rotor and each exciting one of the plurality of phases at an end of the initial drive operation. When the ECU determines that a result of the learning is erroneous, the ECU re-executes the learning by re-executing the initial drive operation.

Abstract: A device is provided for detecting inadequate electric braking and commutation to a safety brake is intended for a vehicle with electric traction, in particular a rail vehicle, which is provided with a traction chain, the system including a first electric, non-safety brake which is integrated in the traction chain and a second safety brake. The device includes a member for commutation from the first brake to the second brake, a device for monitoring the braking performance of the first brake using data for measurement of the intensity of a current, a decision device for commutating from the first brake to the second brake when a predetermined threshold value is exceeded and a device for transmitting a commutation command to the at least one commutation member.

Abstract: This device is an electric safety brake which is intended for an electric traction vehicle, in particular a rail vehicle comprising: a rotating electromechanical machine (10) having permanent magnets having at least one coil with electric terminals (13, 14, 15), a resistive braking torque production device (22), an electromechanical commutator (20) which is capable of reliably connecting the electric terminals (13, 14, 15) of the machine (10) to the braking torque production device (22).

Abstract: A method of estimating stator resistance of a permanent magnet synchronous machine, when the permanent magnet synchronous machine is controlled with an inverter using a control system having an adaptive observer which is augmented with a signal injection, the adaptive observer having a stator resistance estimate ({circumflex over (R)}s) as a parameter, in which method an error signal (?) is obtained from the signal injection, a speed correction term (??) is calculated from the error signal (?), the rotor position estimate is corrected using the speed correction term (??) in the adaptive observer, whereby the error signal (?) is driven to zero. The method comprises the step of correcting the value of the stator resistance estimate ({circumflex over (R)}s) in the adaptive observer when the speed correction term (??) differs from zero.

Abstract: A method for determining the speed of rotation of an unpowered, coasting electric motor, driven, when powered, by an electronic inverter, and without activating switches of the inverter. The steps include determining an electrical frequency of a back emf signal generated at a terminal of the motor or switching node of the inverter when the motor is coasting and determining the mechanical motor frequency and thus speed of rotation by dividing the electrical frequency by the number of motor pole pairs.

Abstract: A method and apparatus for determining rotor position in a stationary rotor of a sensor-less permanent magnet synchronous machine that employs a rotating magnetic field to identify a magnetic axis of the stator without a magnetic direction and then determines magnetic direction by applying pulses along the magnet axis in two polarities.

Abstract: A motor drive for conditioning power to be delivered to a non-motor load includes a voltage feedback circuit that monitors a DC bus voltage and, based on changes in the DC bus voltage, adjusts a power conditioning scheme such that near steady-state load conditions are maintained in response to a transient load condition. The voltage feedback circuit has a voltage sensor that provides voltage feedback to a controller that determines what changes in power conditioning are needed in response to a transient load condition that manifests itself in a change in DC bus voltage.

Abstract: A cleaner that can be operated at motive force of sufficient strength by using a battery voltage as well as by using a AC voltage. The cleaner uses a low-resistance-mode motor to rotate a collecting fan. The low-resistance-mode motor is driven by a motor driver. The motor driver drops a DC voltage converted from the AC voltage, depending on whether the AC voltage is received. Depending on whether the AC voltage is received, the motor driver drives the low-resistance-mode motor using one of the battery voltage and the dropped voltage.