A control device for a braking system of a vehicle is provided, having a first receiving device which receives a provided brake activation intensity variable, a plunger control device which determines a setpoint fill level variable of a plunger, taking into account at least the received brake activation intensity variable, and a corresponding plunger control signal is outputtable so that a ratio of an actual volume and a maximum fillable volume of a storage volume of the plunger is settable corresponding to the determined setpoint fill level variable. For a brake activation intensity variable corresponding to a predefined non-activation intensity variable, the plunger control device determines a fill level variable different from an empty state as the setpoint fill level variable, and outputs a plunger control signal corresponding to the determined setpoint fill level variable to the plunger such that the plunger is at least partially filled.

A brake control device for a brake system. The control device can perform both an interlocking brake control and an antilock brake control. The brake system includes a front-wheel hydraulic circuit, a front-wheel-side braking part; a rear-wheel hydraulic circuit, a rear-wheel-side braking part; and an electrically-operated pump which pressurizes the brake fluid. The brake control device includes a usual voltage mode where the interlocking brake control or the anti-lock brake control is performed when the supply voltage is a first voltage or more, and a low voltage mode where at least one of the interlocking brake control and the anti-lock brake control is performed in a limited manner when the supplied voltage is a second, lower voltage. An operation mode is changed from the usual voltage mode to the low voltage mode when it is determined that the supply voltage becomes lower than the first voltage.

Disclosed is a control method of an electronic parking brake system, which variably controls the duty of voltage applied to a motor upon release of the electronic parking brake system. The control method includes controlling voltage applied to a motor to a first duty ratio upon release of the electronic parking brake system, controlling the voltage applied to the motor to a second duty ratio greater than the first duty ratio if locking of the motor occurs and the motor is not operated, and controlling the voltage applied to the motor to the first duty ratio if locking of the motor is released and the motor begins to operate, after the control of voltage to the second duty ratio.

Systems and methods disclosed herein may be useful emergency braking systems for use in, for example, an aircraft. A system is disclosed that allows emergency braking without the need for a manually operated emergency brake. For example, a system is provided comprising a potentiometer in mechanical communication with a brake pedal, a first electronic switch in electrical communication with the potentiometer, a second electronic switch indicating a displacement of the brake pedal, wherein a brake control valve opens in response to the first electronic switch, and wherein a shutoff valve opens in response to the second electronic switch.

A pressure control valve arrangement for controlling a fluid pressure in an ABS brake system of a vehicle so that, while there is a tendency of individual wheels of the vehicle to lock, the brake pressure in at least one associated brake cylinder can be adaptively adjusted, including: a housing; and at least one diaphragm valve is accommodated in the housing, the diaphragm valve having a diaphragm as the valve body, which diaphragm can be acted upon by introducing pressure medium into a control chamber that is covered on the outside of the housing by a cover so that the control chamber is formed between the diaphragm and the cover, wherein at least one pressure medium channel carrying pressure medium is formed in the housing in the region of the cover, wherein at least one cover has at least one projection projecting into the pressure medium channel in the housing, a pressure medium guiding surface for directing the flow of the pressure medium carried in the pressure medium channel being formed on the projection.

A flat, box-shaped hydraulic block for the mechanical fastening and hydraulic interconnection of solenoid valves, pump elements, etc. of a slip-controlled vehicle brake system connects connections of installation spaces for the pump elements to connectors for a brake master cylinder and connections of receptacles for pressure build-up valves which run past one another via flat chambers on longitudinal sides of the hydraulic block and short blind bores. As a result, the receptacles of the pressure build-up valves are connected to the connectors for the brake master cylinder. The chambers damp pressure pulses of the pump elements of a piston pump.

A method of controlling a vehicle having a transmission system, an engine system, and a braking system includes detecting a braking condition of the braking system. The braking condition is at least one of a brake temperature being above a predetermined brake temperature limit and a braking load being above a predetermined braking load limit. The method also includes detecting a second condition of at least one of the transmission system and the engine system. The method also includes determining whether the second condition satisfies predetermined criteria. Furthermore, the method includes detecting an absolute vehicle acceleration that is below a predetermined acceleration limit. Moreover, the method includes downshifting from a current gear to a lower gear to thereby cause engine braking when the braking condition is satisfied, the second condition satisfies the predetermined criteria, and the absolute vehicle acceleration is below the predetermined acceleration limit.

A vehicle yaw stability control method and a vehicle yaw stability control apparatus are provided. The yaw rate {dot over (ψ)} of the vehicle is measured. A first reference yaw rate {dot over (ψ)}ref is set. A difference yaw rate Δ{dot over (ψ)} is set. Stabilizing braking intervention is triggered when a value of the difference yaw rate Δ{dot over (ψ)} exceeds limits defined by difference yaw rate threshold values Δ{dot over (ψ)}min, Δ{dot over (ψ)}max. Information regarding the shape of the road ahead of the vehicle is acquired. The reliability of the driver steering input δ is evaluated upon stabilizing braking intervention being triggered. In case the driver steering input δ is deemed unreliable a replacement reference yaw rate {dot over (ψ)}refroad is set based on the acquired road shape and a replacement difference yaw rate Δ{dot over (ψ)}road is set whereupon stabilizing braking intervention is performed based on the replacement difference yaw rate Δ{dot over (ψ)}road.

A method and a device for controlling and/or regulating an electric motor. Such electric motors are used for example in motor vehicles in the form of pump motors. In general, the electric motor is supplied with electrical energy from a battery and/or using a generator. The controlling and regulation take place using a high-frequency pulse width modulation (PWM). When the electric motor is started, the PWM is used to continuously increase the motor current required for the operation of the electric motor, e.g. beginning from 0.

A variable speed power converter controls the speed of a load in a material handling system as a function of the torque required to move the load. While the power converter is running, the torque being produced in the motor is determined. The power converter then determines the maximum rotational speed of the motor as a function of the torque currently being produced and of the torque-speed curve of the motor. The power converter then commands the motor to rotate at this maximum rotational speed. The power converter periodically monitors the torque being produced and adjusts the maximum rotational speed of the motor throughout the run.

An electric power tool includes: a motor; a manipulation input receiving unit which receives a user manipulation input for rotating the motor; a mode changeover unit that has one manipulation portion which manipulated by the user; a rotation drive force transmitting unit that switches a transmission mechanism to one of the transmission mechanisms corresponding to the set position of the manipulation portion and transmits a drive force of the motor to a tool output shaft via the switched transmission mechanism; an electric signal output unit that outputs an electric signal corresponding to the set position of the manipulation portion; and a motor control unit that sets the control method of the motor to a control method preset for the electric signal, among a plurality of different types of control methods, based on the electric signal, and controls the motor by the set control method, based on manipulation by the user.

A motor control device comprises: an acceleration upper limit estimating unit; a target acceleration setting unit; a motor control unit; and a deficit calculating unit, wherein the target acceleration setting unit corrects the target acceleration based on the acceleration profile by an amount corresponding to the acceleration deficit within a range in which the target acceleration does not exceed the acceleration upper limit on the basis of the acceleration deficit calculated by the deficit calculating unit to set the target acceleration at each time.

To achieve peak acoustic and power performance, the coil or applied current should be in phase or substantially aligned with the back electromotive force (back-EMF) voltage. However, there are generally phase differences between the applied current and back-EMF voltage that are induced by the impedance of the brushless DC motor (which can vary based on conditions, such as temperature and motor speed). Traditionally, compensation for these phase differences was provided manually and on an as-needed basis. Here, however, a system and method are provided that automatically perform a commutation advance by incrementally adjusting a drive signal over successive commutation cycles when the applied current and back-EMF voltage are misaligned.

A motor control apparatus for controlling a DC motor includes a first detection unit configured to detect an angular velocity of the DC motor, a driven member configured to be driven by the DC motor, a control unit configured to perform, during start-up of the DC motor, feed forward control for changing a control value used for controlling drive of the DC motor from a first control value corresponding to an angular velocity smaller than a target angular velocity to a second control value corresponding to the target angular velocity, and to change the feed forward control to feedback control for controlling the control value based on a detection result by the first detection unit to keep the DC motor at the target angular velocity, and a second detection unit configured to detect whether the driven member has been replaced.

An electric motor, having a stator (465), a rotor (470), and an apparatus for evaluating a signal provided for controlling said motor (110), comprises a receiving unit (430, 440) for receiving a control signal (PWM_mod), which is a pulse width modulated signal (PWM) onto which a data signal (DIR, DATA) is modulated. An evaluation unit (440) is provided for evaluating the modulated control signal (PWM_mod). The unit is configured to extract, from the modulated control signal (PWM_mod), data provided for operation of the motor (110). The control apparatus includes a signal generator (450) configured to generate, on the basis of the extracted or ascertained data provided for operation of the motor (110), at least one control signal for the motor (110), such as a commanded direction of rotation. Piggybacking other control data onto the PWM power level signal reduces hardware investment, by permitting omission of a signal lead which would otherwise be required in the motor structure.

A driving circuit for a single-phase-brushless motor includes a driving-signal-generating circuit to generate a driving signal for supplying, to a driving coil of the single-phase-brushless motor, first- and second-driving currents alternately with a de-energized period therebetween, an output circuit, and a zero-cross-detecting circuit. While measuring a driving cycle from a start of an energized period, during which the output circuit supplies the first- or the second-driving current to the driving coil, to a time when the zero-cross-detecting circuit detects a zero cross of an induced voltage, generated across the driving coil, during the de-energized period, the driving-signal-generating circuit determines a length of a subsequent energized period based on the measured driving cycle, when the zero-cross-detecting circuit detects the zero-cross, and the driving-signal-generating circuit determines a length of an immediately previous energized period as a length of a subsequent energized period, when the zero-cross-detecting circuit does not detect the zero-cross.

Electromotive furniture-flap drive, characterized by an identification device for automatically identifying the type of furniture flap in the installed state of the furniture flap drive.

A variable speed trigger mechanism that allows a user to reverse a direction of a motor and supply variable amounts of power to the motor using a single trigger mechanism. In a first motion, the user can actuate the reversing module to change the direction of the motor coupled to the trigger mechanism. In a second motion, the user can actuate the same trigger and apply variable amounts of power to the motor.

A control circuit for a blender provides low-cost power conditioning through the use of a high resistance which provides temporary power for operation of low-voltage logic circuitry and low-voltage switches for a time sufficient to switch the motor on, and a lower resistance which provides sufficient power for maintaining the motor on state indefinitely as instructed by the low-voltage logic circuitry. Low average power dissipation is provided by powering the low-voltage logic circuitry and low-voltage switches using the high resistance in a standby mode and switching in the lower resistance only when the motor is activated.

A circuit for speed monitoring of an electric motor comprises a circuit for generating a time-frame signal, a circuit for receiving a first signal from a chopper driver circuit designed to drive the electric motor, a circuit for detecting chopper pulses in the first signal, a pulse counter, and a circuit for at least one of outputting and evaluating a state of the pulse counter, after the inactive state of the time-frame has been indicated. The time-frame signal indicates when a time-frame of predefined length changes from an inactive state to an active state and indicates when the time-frame changes back from the active state to the inactive state. The pulse counter is designed to count the detected chopper pulses while the active state is indicated by the circuit for generating the time-frame signal.

In order to process a motor signal (Ia, Um) of a DC motor (4), in particular of an adjustment drive of a motor vehicle, the armature current (Ia) and the motor voltage (Um) of the DC motor (4) are detected and used for determining the back-emf (E) of the DC motor (4), wherein the determined back-emf (E) is used to generate a useful signal (Sf, SEFL), which is in particular speed-proportional, from the armature current signal (Ia) for position sensing or for evaluating an excess force limitation.

A method and device for controlling an electric motor, in particular a machine tool drive, wherein during a sensorless open-loop control mode of operation of the electric motor the speed and the torque are determined from the motor current and the motor voltage, and the moment of inertia of the electric motor torque are determined from the determined motor current and the determined motor voltage, wherefrom then a control torque is determined, which is then associated with an open-loop torque control value and supplied as the torque setpoint value to a control element for setting the motor current and/or the motor voltage in the open-loop mode of operation. As long as the speed is below a minimum speed, the control element receives as input variable a control or pilot control torque generated from a predefined moment of inertia for a sensorless closed-loop control mode of operation of the electric motor.

A power converting apparatus including a power converter that converts a DC voltage into an AC voltage and applies the AC voltage to an AC rotating machine and a control unit that controls the power converter based on an operation command from the outside is provided. The power converting apparatus includes: a first calculating unit that calculates and outputs, from a d-axis current detection value and a q-axis current detection value detected by the AC rotating machine and current command values based on the operation command, first voltage command values to the power converter, magnetic fluxes of the AC rotating machine, and an angular frequency; and a second calculating unit that sets, as an initial value, at least one of the magnetic fluxes and the angular frequency input from the first calculating unit and calculates and outputs second voltage command value to the power converter and an angular frequency.

A computer-implemented fan control method includes measuring a temperature within a computer system and dynamically selecting a fan speed step in response to the temperature received, wherein the fan speed step is selected from a fan speed table defining a finite number of fan speed steps each having an associated fan speed. A fan is operated at the dynamically selected fan speed step, wherein the fan is positioned to drive air through the computer system where the temperature is being measured. The fan output variation is measured over a prescribed time interval and the fan speed table is automatically modified to change the fan speeds associated with each fan speed step, wherein the fan speeds are changed as a function of the measured fan output variation while continuing to drive the fan.

A circuit includes a comparator having input terminals configured to be coupled across a drive transistor adapted to drive a phase of a motor. The comparator senses a drive current of the motor phase, said sensed drive current represented by a periodic signal whose period is indicative of motor speed. A motor speed calculation circuit receives the periodic signal and processes the periodic signal to determine a speed of the motor.

An electric power tool includes a motor that rotary drives an output shaft; an operation unit to input a drive command of the motor; a torque setting device that sets an upper limit value of a rotational torque of the output shaft in accordance with a torque setting command; and a control device that drives the motor in one of a forward direction and a reverse direction in accordance with the drive command, and stops driving of the motor when the rotational torque of the output shaft has reached the upper limit value set by the torque setting device during driving of the motor. The torque setting device is configured to set the upper limit value such that the upper limit value during driving of the motor in the forward direction and the upper limit value during driving of the motor in the reverse direction are different.

A voltage regulator for a pair of electric motors has an input for a signal indicative of the desired speed for the motors and a pulse width modulation control circuit device. A control module provides a conditioning signal to the control circuit to output to the motors a square wave voltage having a duty-cycle which varies according to a predetermined function of the signal applied to the input of the regulator. The control circuit device has first and second electronic solid state switches associated with the motor and controlled by the control module.

Embodiments of the present method and system permit an effective method for determining the optimum selection of pulse width modulation polarity and type including determining machine parameters, inputting the machine parameters into a predicted duty cycle module, determining the optimum polarity of the pulse width modulation for a predicted duty cycle based on a pulse width modulation generation algorithm, and determining the optimum type of the pulse width modulation for a predicted duty cycle based on the pulse width modulation generation algorithm.

A lower limit value setting unit (52) variably sets a lower limit value (Vth) of a target voltage (Vh*) in a range of a voltage that is higher than the maximum value of voltages (Vb1, Vb2) of power storage devices and is not affected by a dead time provided for converters, based on temperatures (Tb1, Tb2) and required electric powers (Pb1*, Pb2*). A maximum value selection unit (53) sets the maximum value among the voltages (Vb1, Vb2) of the power storage devices and required voltages (Vm1*, Vm2*) of motor-generators, as the target voltage. A target voltage limiting unit (54) compares the target voltage with the lower limit value (Vth), and if the target voltage is lower than the lower limit value (Vth), the target voltage limiting unit (54) sets the lower limit value (Vth) as the target voltage (Vh*).

A method for monitoring input power to an electronically commutated motor (ECM) is described. The method includes determining, with a processing device, an average input current to the motor, the average input current based on a voltage drop across a shunt resistor in series with the motor, measuring an average input voltage applied to the motor utilizing the processing device, multiplying the average input current by the average voltage to determine an approximate input power, and communicating the average input power to an external interface.

A device and method to determine the stopping rotor position of a washing machine motor includes an inverter, a permanent magnet synchronous motor, and an electronic motor controller. The controller determines the stopped rotor position of the motor by measuring induced currents in the stator field coils of the motor. While the motor is de-energized and slowly rotating, the controller directs the inverter to connect all of the stator field coils of the motor together. The stator field coils may be connected to a common D.C. rail, output from an A.C.-D.C. converter of the washing machine. In an embodiment, the controller determines the rotor position based on the polarities of current induced in the stator field coils. In another embodiment, the controller determines the rotor position based on the phase angle and angular frequency of the three phase currents, transformed into a stationary reference frame.

The invention relates to an electric motor assembly, particularly for driving a fan for an engine cooling system and/or an air conditioner of a motor vehicle, comprising an electric motor and a motor control device for activating the electric motor. According to the invention, the motor control device can be adjusted according to a characteristic curve (1,2,3,4) of the electric motor and/or of the fan, and thereby the power and/or rotational speed of the electric motor can be adjusted.

A detection control system includes a sensing unit, a control module and a driving module for a motor including a rotor and a stator. The sensing unit electrically connects the motor to sense a first and a second magnetic pole of the rotor cross a chip disposed between the rotor and the stator; a third magnetic pole is alternated to a forth magnetic pole of the stator to generate a sensing signal. A detection unit of the control module detects a kickback voltage value generated by a first current value changing to a second current value to calculate a minimum current value to generate a detecting signal. A timing unit receives the sensing and the detecting signal to calculate a first and a second period of time, and a discharging time. The driving module drives the rotor by receiving a control signal the control unit generates by controlling an alternating time.

The present application discloses a control circuit for a power tool and a method for manipulating the power tool. The control circuit has a detection circuit for battery packs, a calculating control circuit, a battery capacity indicating circuit for indicating the calculation result of the battery capacity, and a current measure and calculating circuit for measuring the current flowing through motors. The calculation result further includes the voltages consumed by the battery pack internally and the discharge loop. The method for manipulating the power tool includes pressing the switch to electrically connect the motor and the battery pack, measuring the parameters of the battery pack and allowing the motor to operate or not according the measured parameters. Further, after the motor is in operation, the battery capacity is calculated and the results are displayed.

An electric tool comprises a removable battery pack 2 as a power supply, a motor M as a power source, a drive unit being driven by said motor, a switch SW as an operation input unit, and a control circuit CPU controlling the driving of said motor according to the operation of said switch. The electric tool further comprises a power supply connection unit that enables a plurality of battery pack types, which have different rated output voltages, to be selectively connected, and an identification means that identifies the type of said battery pack that has been connected. Said control circuit is configured to control an output of said motor based on identification information for the type of said battery pack that has been connected, provided by said identification means.

Assemblies for HVAC systems and methods of operating HVAC systems are disclosed, including a method of operating an HVAC system having a compressor assembly and a condenser assembly. The compressor assembly includes a compressor having a compressor motor that is susceptible to backspinning and capable of generating electric power when backspinning. The condenser assembly includes a condenser motor operatively coupled to a fan. The condenser assembly is electrically coupled to the compressor assembly. The method includes using the condenser motor as an electric load to dissipate electric power generated by the compressor motor when the compressor motor backspins.

A motor driving apparatus is applied to a fan and motor mechanism and a voltage supply unit. The motor driving apparatus includes a motor driving unit, a voltage division resistor, a first resistor, a first switch unit, a second resistor, a second switch unit, a third resistor, a third switch unit, a transistor switch, and a pulse width modulation unit. The first switch unit, the second switch unit, and the third switch unit are configured to select the rotational speed upper limitation of the fan and motor mechanism for suppressing noise.

An integrated circuit for controlling an electric motor, which has a primary component with a coil and a permanently magnetic secondary component cooperatively connected via an air gap to the primary component, has a semiconductor substrate in which are integrated a microcontroller and/or a pre-amplifier for controlling the coil of the electric motor. For detecting the position of the permanently magnetic secondary component, at least two magnetic field sensors with their measurement axes aligned crosswise relative to each other are integrated in the semiconductor substrate.

A control circuit for a fan includes a fan controller, a switch controller, and a frequency detector. When a pulse-width modulation (PWM) signal output pin of the fan controller outputs PWM signals, the frequency detector outputs a high level signal, connecting an input pin of the switch controller to an output pin of the switch controller. The fan receives the PWM signal. When the PWM signal output pin of the fan controller does not output PWM signals, the frequency detector outputs a low level signal, such that the output pin of the switch controller does not output any signal. In this state, the fan receives a high level signal through a resistor and a power supply, enabling the fan to continue operating.

The invention relates to a method for detecting blocking or sluggishness (M1, M3) of a DC motor (2). The method comprises the following steps: applying a voltage pulse (Uv,t=Os) to the DC motor (2); monitoring a motor current (IMotor) flowing through the DC motor (2); detecting a maximum value of the motor current (IMotor) following the application of the voltage pulse; checking whether a change in the motor current (IMotor) after reaching the maximum value exceeds a specific amount; signalling the blocking or the sluggishness (M1, M3) of the DC motor (2) if the change in the motor current (IMotor) after reaching the maximum value exceeds the specific amount.

An apparatus or method which accepts a burst of pulses at a frequency which may not be tightly controlled and converts this into a trajectory command that is a suitable motion profile for an incremental motor control application. The output of the invention can be a pulse stream that can be fed to an existing incremental pulse input motor drive or the invention can be embedded into a motor drive where its output is a numerical sequence that defines a physically realizable trajectory to be fed to the control circuits and software within the motor drive.

A motor current detection apparatus in the present invention includes: a current detection unit, a first filter, and a second filter. The detection unit detects a conduction current flowing from a battery to a brushless motor and outputs a conduction current signal corresponding to the detected conduction current. The first filter extracts a first current signal which is included in the conduction current signal outputted from the detection unit and is a signal component in a frequency band equal to or lower than a predetermined first cutoff frequency. The second filter extracts a second current signal which is included in the conduction current signal outputted from the detection unit and is a signal component in a predetermined frequency band within a frequency band equal to or lower than a predetermined second cutoff frequency higher than the first cutoff frequency and having the second cutoff frequency as a maximum value.

A control system (128) for controlling a switched reluctance (SR) machine (110) having a rotor (116) and a stator (118) is provided. The control system (128) may include a converter circuit (122) operatively coupled to the stator (118) and including a plurality of switches (132) in selective communication with each phase of the stator (118) and a controller (130) in communication with each of the stator (118) and the converter circuit (122). The controller (130) may be configured to determine a position of the rotor (116) relative to the stator (118), and generate a modulated switching frequency (152) based on the rotor position.

A rotation speed control circuit is disclosed. The rotation speed control circuit includes a temperature-controlled voltage duty generator, a pulse-width signal duty generator, a multiplier and a rotation speed signal generator. The temperature-controlled voltage duty generator converts temperature-controlled voltage to digital temperature-controlled voltage and executes linear interpolation operation according to a first setting data so as to output temperature-controlled voltage duty signal. The pulse-width signal duty generator coverts pulse-width input signal to a digital pulse-width input signal and executes linear interpolation operation according to a second setting data so as to output a pulse-width duty signal. The temperature-controlled voltage duty signal and the pulse-width duty signal are executed for multiplication by the multiplier so as to output mixing-duty signal. The rotation speed generator receives the mixing-duty signal and a third setting data, and executes a minimum output duty operation so as to output a pulse-width output signal.

The present invention discloses a controller and a method for improving motor driving efficiency. According to the present invention, multiple control parameters are inputted to the controller so that the controller can adjust timings of PWM driving signals for driving the motor to advance or delay the turned-ON or turned-OFF points, whereby the motor is driven efficiently.

The electric tool is powered by a secondary battery as a power source, and includes: an output section configured to be transmitted thereto a rotation of a motor directly or through a decelerator; a voltage measurement section that measures a battery voltage; a storage means that stores, as a reference voltage, a voltage value of the battery voltage measured preliminarily when a motor-lock is occurring; and a control means that controls a driving of the motor. The control means is configured to decide that the motor is being locked and then stop or decelerate the motor upon detecting that the battery voltage measured through the voltage measurement section is maintained lower than or equal to the reference voltage stored in the storage means for a predetermined period of time during the driving of the motor.

A method for controlling a motor is provided. The method comprises obtaining electrical signals of the motor with a signal unit, the electrical signals comprising a motor torque and an angular velocity, calculating a voltage phase angle of a voltage vector with a calculating component, wherein a command torque, the motor torque, the angular velocity and a voltage amplitude of the voltage vector are inputs of the calculating component, and wherein the voltage phase angle is a variable and the voltage amplitude is a constant. The method further comprises modulating the voltage phase angle and the voltage amplitude to a switching signal for controlling an inverter; converting a direct current voltage to the voltage vector according to the switching signal, and applying the voltage vector to the motor.

Provided is an apparatus for compensating offset of a current sensor detecting a motor current supplied by an inverter for PWM (Pulse Width Modulation) control of a motor, the apparatus including a current controller providing a PWM signal generated based on the motor current detected by the current sensor to the inverter, calculating an offset using the motor current detected by the current sensor in response to presence and absence of the PWM control of the motor, or offset-compensating the motor current detected by the current sensor.

A circuit configuration for driving an electric motor includes a signal evaluation module, which stores a number of output patterns. An input pattern is specified, and as a function of the input pattern, one of the output patterns is output, by which the electric motor is driven.

A wiper device that includes: a wiper motor that swings a wiper blade that is coupled to the wiper motor through a wiper arm to-and-fro over a window pane between an upper return position and a lower return position; and a drive component that gradually increases power supplied to the wiper motor until the rotation speed of the wiper motor reaches a specific speed when the wiper motor has been restarted from a stationary state of the wiper blade between the upper return position and the lower return position.