Abstract: Provided is a drive regenerative control system of a drivee with a motor superior in torque and weight balance and suitable for miniaturization as the drive source. In a drive regenerative control system having a drive source with an electric motor, a drivee, a control circuit having a drive control circuit of the motor and a regenerative control circuit, and a detection unit for detecting the driving status of the drivee, the drive control circuit and regenerative control circuit have a control unit for controlling, linearly or in multiple stages, the duty ratio of the drive or regenerative signal to be supplied to the motor based on the phase difference of the phase of the detection signal from the detection unit and the command value signal to the motor.

Abstract: A variable reluctance electric power system which comprises an alternator and a motor having a rotor with longitudinal lobes and no windings, commutators, slip rings, magnets, or laminations. The alternator and the motor have stators which have conventional windings and laminations and a rotor which is polarized using a static field winding which surrounds but does not touch the rotor. The alternator and the motor may be coupled with current from the alternator driving the motor and solid state power devices controlling the frequency of the current to insure that the current from the alternator is always synchronized with the motor rotor.

Abstract: An upper limit value setting unit of a control device conducts integration on the change in battery power, and determines whether the integrated value is lower than a preset first threshold value (negative value). When determination is made that the integrated value is lower than the first threshold value, and the battery power difference is lower than the second threshold value (negative value), the upper limit value setting unit sets Vup2 that is lower than the general Vup1 as the upper limit value of the inverter input voltage command.

Abstract: A stabilizer control device includes: an electric motor having a regenerative function; a stabilizer, connecting a left wheel and a right wheel, that is capable of altering a roll rigidity via the electric motor; vehicle behavior detection device that detects a vehicle behavior; regenerative current setting device that sets a regenerative current of the electric motor based on the vehicle behavior detected by the vehicle behavior detection device; and regenerative current adjusting device that adjusts the regenerative current of the electric motor so that the regenerative current set by the regenerative current setting device is reached. The spring reaction force against the twist of the stabilizer rotates the electric motor to thereby generate electricity. Vehicle behavior such as body roll is detected and the regenerative current of the electric motor is set based on the detected vehicle behavior to restrain or accelerate the twist or return of the stabilizer.

Abstract: An ECU executes a program including the steps of calculating a capacitor charging electric power value W (1) (a value of electric power to be stored in a capacitor) based on a voltage value of the capacitor, if a vehicle is under braking, calculating a regenerative electric power value W (2) (a value of electric power to be generated by an MG (2) under regenerative braking), if the capacitor charging electric power value W (1) is larger than the regenerative electric power value W (2), driving an engine, generating electric power by MG (1) by driving force of the engine, and charging the capacitor with the electric power generated by the MG (1) and the MG (2).

Abstract: According to the invention, there is provided a control apparatus for a motor generator of a hybrid vehicle. The control apparatus includes a determiner, a comparator, and a controller. The determiner works to determine values of a first and a second parameter, which are defined in the same unit and respectively representative of economic benefits obtainable by operating the motor generator in generator and motor modes. The comparator works to compare the determined values of the first and second parameters. The controller works to control the motor generator to operate in the generator mode when the value of the first parameter is greater than that of the second parameter and in the motor mode when the value of the second parameter is greater than that of the first parameter. With such a configuration, the control apparatus can economically shift operation of the motor generator between the generator and motor modes.

Abstract: A power-supply unit for automobiles, connected to an electrically-driven brake device which generates braking forces by being electrically driven, an electric generator capable of generating braking forces for a vehicle by power generation, and a storage device for storing electric power, the power-supply unit comprising a first power supply line for connecting the electric generator with the storage device, a second power supply line for connecting the first power supply line with the electrically-driven brake device, and power-source connection means provided on the second power supply line and have interrupting function.

Abstract: A motor drive inverter control apparatus includes a rectifier circuit for rectifying an AC power supply, an inverter circuit driven by an output from the rectifier circuit, a motor driven by an output from the inverter circuit, a first capacitor coupled in parallel to the output of the rectifier circuit, and a second capacitor coupled in parallel to the first capacitor via a diode. The second capacitor has capacitance not less than three times that of the first capacitor. Although the second capacitor shows a ripple content not less than 90% during practical use, it well absorbs regenerative energy produced by the motor. As a result, elements of the apparatus can be prevented from degrading caused by an over-voltage, and the apparatus can be downsized and reduced its cost.

Abstract: A motor driving apparatus applicable to various types of motor driving apparatuses and having a power storage section for storing a regenerative current and supplying power to an inverter section at the time of acceleration. The motor driving apparatus further comprises a converter section, a DC link, and an inverter section, thereby driving a motor. Connected to the DC link is the power storage section including a capacitor, a charging circuit, a discharging circuit and a diode. The regenerative current produced at the motor deceleration is stored in the capacitor through the diode. The power stored in the capacitor is outputted to the DC link by turning a switching element of the discharging circuit ON at the motor acceleration. Furthermore, the charging circuit has a boost switching regulator circuit for charging the capacitor to the given upper limit voltage equal to or larger than voltage of the DC link and a current limitation circuit for limiting a charging current to the given upper limit.

Abstract: The present invention provides an instantaneous fan stopping method and structure thereof. The method and structure can eliminate the inertial rotating state of the fan when the power supplied to the fan is cut off. In accordance with the present invention, a closed circuit is formed between the two terminals of the coil used to drive the fan. When the closed circuit is formed, the inertial rotation of the fan can generate an induced current in this coil, which, in turn, generates a magnetic force to stop the fan.

Abstract: The present invention relates to a propeller drive arrangement for vessels used in water-borne traffic, and specifically to a propeller drive arrangement containing a propulsion unit, and to such an arrangement, which contains a propulsion unit, which is turnable relative the hull of the vessel. Particularly the present invention relates to a system and a method for braking a motor of a propulsion unit. The solution for braking the propulsion unit according to the present invention is based on short-circuiting a permanently magnetized motor.

Abstract: A motor drive circuit includes a first transistor. The collector of a second transistor is connected to the emitter of the first transistor in series. A motor is connected to a connection point between the first and second transistors. A first brake control circuit turns off the first transistor and turns on the second transistor in accordance with a brake operation instruction signal. A second brake control circuit forces the first transistor to be turned OFF in accordance with the brake operation instruction signal independently from the first brake control circuit.

Abstract: A hybrid propulsion system. The system comprises one or more hybrid propulsion traction drives having an electric motor operable to produce mechanical power for propulsion. A hybrid propulsion traction drive is operable to receive power from an on-board power generation system. The electric motor is operable to receive power from an energy storage unit and operable to supply power to the energy storage unit. The energy storage unit may be coupled to the electric motor via a switch.

Abstract: A control apparatus for an electric railcar that provides control so that when rotational speed of a motor decreases below a required value, torque of the motor will decrease at a required rate of change, a current limiter for limiting a torque current command “(A)Iqp” output from a current command arithmetic unit is provided to ensure that when the rotational speed of the motor decreases below the required value, the torque current command will be limited to a command value “(B)Iqp” smaller than that command value, and to ensure that a carrier frequency at which PWM signals are created when switching elements of the electric power converter are controlled by carrier generator is controlled to become lower than a carrier frequency existing when the rotational speed of the motor decreases below the required value.

Abstract: A motor power supply including a DC supply part having a pair of supply terminals; an inverter having a pair of connection terminals respectively connected to the supply terminals thereof to receive DC power therefrom and to supply AC power to a motor, a breaking resistor and a control switching element disposed in parallel in an additional line connecting the pair of connection terminals to each other, a control switching element disposed with the breaking resistor in the additional line, a breaking switch disposed to one of the connection terminals and switched to either a normal position or a breaking position connecting the one connection terminal to a corresponding supply part or to the additional line, a speed detector detecting a motor speed and a control part controlling the breaking switch to switch to the breaking position and controlling the control switching element so that an on-off interval of the control switching element is controllable depending on the detected speed.

Abstract: The invention provides techniques for reducing or altering the magnetic noise of an AC rotary electric machine. A magnetic noise reducing harmonic current of order n, whose frequency is n times the frequency of the fundamental frequency component of a polyphase AC current fed to an armature of a polyphase AC rotary electric machine, is superimposed on the polyphase AC current, thereby reducing or altering a harmonic component having a frequency (n?1) times the frequency of the fundamental frequency component and occurring due to a radial magnetic excitation force acting radially on an iron core of the AC rotary electric machine.

Abstract: A power supply apparatus driving and controlling motor generators (MG1, MG2) includes a battery (10) generating an input voltage (Vb), a converter (110) converting the input voltage into a motor operating voltage (Vm) according to a voltage command value (Vmr), a smoothing capacitor (120) holding the motor operating voltage, inverters (131, 132) receiving the motor operating voltage and driving and controlling the motor generators (MG1, MG2) according to a torque command value (Tref), and a control unit (15) generating the voltage command value and the torque command value.

Abstract: An apparatus for supplying a power to a motor for driving a mechanism that conveys a cartridge of a storage medium includes an accumulating unit that accumulates a regenerative power generated by the motor in a capacitor; and an adjusting unit that adjusts, when the power is supplied to the motor, a ratio of power supply from a power source to power supply from the capacitor.

Abstract: In the present invention, several polyphase devices are connected together: an inverter (420), and electrical rotating machine (440), and a resistive load or braking resistor (430). The purpose of the resistive load is to dissipate excess electrical which may be produced when the inverter acts to slow down the rotating machine (440), causing the rotating machine to act as a generator. In common art, this resistive load is a single DC resistor coupled to the DC link of the inverter via a separate resistor control transistor. In the present invention, the resistive load is a mesh connected array of resistors, and is electrically connected to the same inverter output terminals that the rotating machine is connected to. When it is desired that the resistors absorb energy, for example from a braking operation, then the harmonic content of the inverter output is adjusted, thus placing voltage differences across the resistor array (430) and causing current to flow in the resistors.

Abstract: A controlling method of a motor state described herein detects the motor operation in a regeneration state or a motor state. The output frequency value of an AC motor drive is calculated and adjusted to stabilize the voltage of a DC bus such that over-voltage protection is avoided. Therefore, a stable load current is obtained and the time for slowing down the motor is shortened.

Abstract: An X-ray computed tomography apparatus wherein an X-ray is generated by a generator and an X-ray data resulting from the X-ray is detected by a detector. The apparatus includes a supporter, a driver, a body, and a converter. The supporter is configured to support the generator and the detector. The driver is configured to drive the supporter. The body is configured to incorporate the supporter and the driver. The converter is provided at a bottom of the body and is configured to convert regenerative energy caused by the driver to heat energy.

Abstract: This invention is a system and a method that uses the braking resistor, commonly used and available in electrically or hybrid-electrically propelled vehicles, to limit the precharge current during the startup of a high power ultracapacitor pack energy storage device and/or safely and rapidly discharge an ultracapacitor pack for maintenance work or storage to lengthen the life of the individual ultracapacitor cells and, correspondingly, the whole pack. The use of the braking resistor for precharging an ultracapacitor energy storage pack is an effective and less expensive method compared to other methods such as a separate DC-to-DC converter. This method includes the control logic sequence to activate and deactivate switching devices that perform the connections for the charging and discharging current paths.

Abstract: The present invention is directed to the provision of a servomotor driving apparatus that feeds energy stored in a power storage part connected with a DC link that connects a rectifier circuit with an inverter circuit so that the energy stored in the power storage part can be reduced. A motor driving apparatus (1) includes: a step-up type DC/DC converter circuit (11) for boosting voltage appearing at an output of the power storage part (C1) connected with a DC link; and a DC/AC conversion circuit (12, 14) for converting the boosted DC electric power into AC electric power and feeding it to an electric power source.

Abstract: If a traveling speed of a carriage calculated by a speed converter is larger than an estimated speed in a deceleration section, braking is conducted by a braking method corresponding to a manipulated variable generated by a drive control unit. Owing to this type of braking, the traveling speed is reduced to the estimated speed. At this time, braking is conducted corresponding to an error between a target speed and the traveling speed, or an error between a speed (corresponding to an error between a current position of the carriage and a target stop position) and the traveling speed. Therefore, even if a braking force required for braking differs depending on individual variability of the carriage control device or operative condition of the carriage, braking can be conducted with a suitable braking force.

Abstract: A method and an apparatus for controlling the mains bridge of a four-quadrant PWM frequency converter provided with a DC intermediate circuit when the power is flowing in the direction towards the supply network, said frequency converter being provided with an AC inductor (9) to be connected to an alternating voltage source (UU, UV, UW), a controlled mains bridge (10), a DC intermediate circuit (14) and a controlled load bridge (11) for feeding a variable-frequency alternating voltage (US, UR, UT) into a load (12), and said mains bridge being provided with controlled semiconductor switches (V1–V6) and shunt diodes (D1–D6), and wherein the mains bridge (10) is mainly controlled in such manner that the controlled semiconductor switch in the upper branch of the phase having the highest supply voltage instantaneous value and the controlled semiconductor switch in the lower branch of the phase having the lowest supply voltage instantaneous value are conducting.

Abstract: A closed-loop system 10 is provided for controlling a DC motor. The system includes a DC motor 12, a controller 18 associated with the motor and constructed and arranged to control operation of the motor, a voltage sensor 14 constructed and arranged to measure a voltage supplied to the motor, a speed sensor 16 associated with the motor and constructed and arranged to obtain a measured speed of the motor, and a conditioning circuit 21 constructed and arranged to receive a speed signal and condition the speed signal to provide to the controller, a nominal speed based on the voltage supplied to the motor, or nominal rate of acceleration or deceleration upon a change in the desired speed. The controller 18 is constructed and arranged to compare the measured speed with a certain speed, that is less than the nominal speed, at a voltage corresponding to a measured voltage, and if the measured speed is less than the certain speed, a fault condition is defined by the controller.

Abstract: A drive unit of the invention comprises a motor that can input/output motive power to/from a drive shaft, a drive circuit that performs drive control of the motor, a fuel cell that is connected to the drive circuit without the intervention of a voltage converter such that electric power can be output, a charge/discharge portion that is connected to the fuel cell in parallel and to the drive circuit such that electric power can be output and that has at least one capacitor whose voltage in a fully charged state is higher than an inter-open-terminal voltage of the fuel cell, a diode that is installed between the fuel cell and the charge/discharge portion such that electric power can be output only in a direction from the fuel cell to the charge/discharge portion, and a drive control portion that controls the drive circuit such that drive control of the motor is performed on the basis of required motive power to be transmitted to the drive shaft.

Abstract: The present invention provides regenerative passive and semi-active suspension systems. A regenerative suspension system generally includes at least one regenerative damper, a module, an electric switch, and a battery. The at least one regenerative damper converts mechanical vibration energy within a vehicle into a voltage, which the damper passes to the module. The module measures the voltage from the regenerative damper, and in response, changes electric switch settings for each regenerative damper between an open circuit, a closed circuit completed by a power resistance, and a closed circuit completed by circuitry for charging a battery. Additionally, the module sets electric switch levels to adjust the damping forces within each regenerative damper.

Abstract: The present invention includes a power drive electronics apparatus connected between a frequency variable generator and an electric motor. The power drive electronics apparatus includes a three-phase diode rectifier having a three-phase AC input, a positive DC output terminal and a negative DC output terminal. A capacitor is connected between the positive DC output terminal and said negative DC output terminal. The three-phase AC input is operably connected to the electric motor and the positive DC output terminal is operably connected to the frequency variable generator's rotor winding. The power drive apparatus also includes a diode having an anode and a cathode, wherein the cathode is connected to the positive DC output terminal of the three-phase diode rectifier, and the anode is connected to a battery.

Abstract: In a portable electronic device having a data-storage drive that employs a rotatable data-storage carrier, as the data-storage carrier undergoes spin-up and spin-down cycles when the data-storage drive is being accessed, the electronic device recaptures at least a portion of the kinetic energy of the rotating data-storage carrier during the spin-downs to generate electrical currents and use them to either charge the battery or reduce the battery drain.

Abstract: A method and apparatus for braking a motor has a braking circuit that intermittently shorts the windings of the motor to brake the motor. The braking circuit is powered by back EMF generated by the motor when power is disconnected from the motor.

Abstract: The present invention is directed to the termination of the occurrence of wheel slip/skid and prediction and prevention of the onset of wheel slip/skid in a locomotive. In one configuration, a lookup table of adhesion factors is used to predict the occurrence of wheel slip/skid.

Abstract: A method and system for controlling vehicle door position having reduced power supply current requirements reduces the cost and weight of a vehicle and further reduces power consumption. The vehicle door control system includes an inverter for converting a DC power source to an AC voltage for driving the motor. The inverter is preceded by a boost converter that maintains a constant voltage at the inverter input, and a capacitor is provided between the converter and inverter for energy storage. Kinetic energy is returned from the door and mechanical portions of the motor through the inverter and stored on the capacitor, reducing the power required from the power source. Operation of the inverter and converter are controlled by timers and detection mechanisms that cease operation of the inverter and converter when the door is held in a fully closed or open position for a predetermined interval.

Abstract: A motor driving apparatus including a regeneration control function and a power storage device for accumulating a regenerative current and for supplying an inverter section with electric power during acceleration. The inverter section is connected to a converter section by a DC link to which regeneration start detecting means and the power storage device are connected. When the regeneration start detecting means detects that a voltage at the DC link reaches a regeneration control start voltage, a controller controls switching elements and starts regeneration control. The regenerative current is accumulated in the capacitor through a diode. When a motor is in a power running state, the switching elements are turned on to apply the voltage at the power storage device to the DC link, and the charged power is utilized for motor acceleration.

Abstract: To provide a power transmission device that can increase the range of speed variation between an engine and a power output shaft and effectively achieve reduction in size and cost of the device arrangement. The speed reduction ratios from an engine 1 to first output shaft 4c, 5c of first and second power distributors 4, 5 are different from each other. A speed change unit 10 is provided between the first output shaft 4c of the first power distributor 4 and a power output shaft 11 linked with driving wheels 2, 2 of the vehicle, and rotation transmission therebetween is achieved at a plurality of stages of speed reduction ratio. The rotation transmission from the first output shaft 5c of the second power distributor 5 to the power output shaft 11 is achieved via gears 20, 15b or rotation transmission mechanisms 15, 14 of a speed change unit 10 at a plurality of stages of speed reduction ratio.

Abstract: Disclosed is a control apparatus for a hybrid vehicle having an engine, a drive motor (3) that regenerates power, and an electric power storage device (6) that gives/receives power to/from the drive motor (3). The control apparatus includes power consumption means (2) for consuming power; a sensor (26, 27) that detects a state of charge of the electric power storage device; means (18, 23, 51) for detecting a driving state of the vehicle; and a controller (9).

Abstract: A control apparatus for controlling a regenerative operation of a vehicle motor includes a vehicle motor as a drive source of a vehicle, an energy storage device, including plural cells, for storing regenerative energy generated by a regenerative operation of the vehicle motor, and a total voltage measuring device for measuring a total voltage that is a sum of inter-terminal voltages of the plural cells, a cell voltage judgment device for determining whether the inter-terminal voltage of any one of the plural cells exceeds a predetermined regeneration limitation voltage, a total voltage estimating device for determining, when it is determined by the cell voltage judgment device that the inter-terminal voltage of any one of the cells exceeds the predetermined regeneration limitation voltage, an estimated total voltage which is defined as a total voltage at a time when the inter-terminal voltage of the one of the cells reaches a regeneration prohibition voltage that is higher than the predetermined regenerative

Abstract: A vehicle and method of operating a vehicle including a motor that supplies a driving force to a wheel, a battery that supplies electric power to the motor and receives regenerative electric power from the motor and a controller that detects a state of the battery and sets, based on a detected state of the battery, a first upper limit value and a first lower limit value for a voltage value and an electric current value that is output from the battery to the motor, and a second upper limit value and second lower limit value for the voltage value and the electric current value that is input from the regenerative electric power to the battery.

Abstract: A multi-stage dynamic braking resistor network (23) is provided that includes a plurality of dynamic brake resistors (1a–d) for dissipating, as heat, regenerative energy inputted onto a system bus (17) by a motor or actuator (19), and a plurality of switches (31a–d) for connecting the dynamic brake resistors (1a–d) to and from the system bus (17), respectively. The multi-stage dynamic braking resistor network (23) further includes a control circuit (25) for controlling the switches (31a–d) such that the dynamic brake resistors (1a–d) are connected to and from the system bus (17) on the basis of a predetermined voltage threshold of the system bus and on the basis of a predetermined rotation pattern.

Abstract: A disc drive includes a disc mounted to a rotatable spindle, a motor coupled to the spindle, and motor control circuitry. The motor has a motoring mode in which it rotates the spindle and a braking mode in which is decelerates the rotating spindle and generates power. The motor control circuitry is adapted to control the modes of the motor. The disc drive also includes an auxiliary power output that is generated while operating the motor in the braking mode. The auxiliary power output is made accessible to electronic components that are collateral to the disc drive.

Abstract: The position and speed and, in some embodiments, direction of rotation of a motor for turning the rod of an object such as a window covering is determined by placing a braking magnet next to the motor and a piezoelectric element between the braking magnet and motor. As the motor rotates, the piezoelectric element generates a signal that can be used to determine the speed of rotation and also the position of the motor (and, hence, the position of the object being moved). The magnet brakes the motor from turning under the weight of the object when the motor is deenergized.

Abstract: The regenerative braking method and system for an electric vehicle in which regeneration current is calculated and controlled using control of an air conditioning system to consume a portion or all of the surplus regeneration power, thereby enhancing braking performance and feel. Control includes calculation of a regeneration current and comparison of the regeneration current to battery current to calculate the surplus regeneration power.

Abstract: An actuator including an electric motor driven by a drive circuit powered by a power source, and a load coupled to the electric motor. The actuator further includes a spring biasing the load to a first position, and a microcontroller coupled to the electric motor to commutate the electric motor. Upon failure of the power source, the spring returns the damper to the first position, and, as the spring returns the load to the first position, the electric motor is spun to generate electricity that is used to power the microcontroller. The microcontroller can govern a speed at which the spring returns the load to the first position. In addition, a potentiometer can be used to indicate when the load approaches the first position so that the microcontroller can slow the speed of return prior to the load reaching the first position.

Abstract: An engine start system includes a starter starting an engine, a starter drive relay controlling the starter and an engine ECU connected to a starter switch for controlling on/off of the starter drive relay based on a predetermined start condition. The engine start system further includes a normally closed relay connected to the starter switch, the engine ECU and the starter for establishing a de-energized state between the starter switch and the starter upon energization from the engine ECU to an exciting coil and establishing an energized state between the starter switch and the starter upon de-energization of the exciting coil. The engine ECU includes a circuit energizing the exciting coil of the normally closed relay upon turn-on of the engine ECU.

Abstract: There are provided as drive sources an engine 2, a front motor 3 provided on a front wheels 8 side of the vehicle and a rear motor 4 provided on a rear wheels 9 side of the vehicle, and in executing a regeneration of deceleration energy when braking, a regeneration capacity of the front motor 3 and a regeneration capacity of the rear motor 4 are calculated, respectively, so that the regeneration is executed with either of these motors 3, 4 which can provide a larger regeneration capacity.

Abstract: A protective device includes a signal input intended for connection to a sensor, a signal output intended for connection to an evaluation unit, and an isolation element for galvanically separating the signal input from the signal output. The provision of the protective device prevents a transmission of overvoltages from the sensor to the evaluating unit.

Abstract: A control apparatus for a hybrid vehicle for generating an appropriate amount of regeneration energy during deceleration. A control apparatus for a hybrid vehicle including an engine and electric motor for driving the hybrid vehicle wherein the engine comprises cylinders capable of deactivated operations and the motor executes regenerative braking when the vehicle is decelerating. The control apparatus of the present invention includes a cylinder deactivation determination device for determining whether or not the vehicle speed is appropriate for executing the cylinder deactivated operation, a regeneration amount calculating device for detecting whether the vehicle state is appropriate for regeneration and calculates the amount of regeneration; and further includes a compensation amount calculating device that compensates the amount of regeneration based on an all cylinder deactivated operation and the engine rotation speed.

Abstract: An apparatus for controlling deceleration of a DC motor which is driven in a forward operating direction with a forward-drive electric current applied thereto by a forward driving device, wherein the forward motor driving device applies the forward-drive electric current in the form of pulses to the DC motor during its deceleration, and wherein a plugging-braking device operable while the motor is subjected to a regenerative brake or operated in a non-braked state is operated to apply a reverse-drive electric current in the form of pulses to the motor, to apply a plugging brake to the motor, such that at least one pulse of the reverse-drive electric current follows every predetermined number of pulses of the forward-drive electric current.

Abstract: A regenerative damper and method for regenerative damping are disclosed. The regenerative damper uses the kinetic energy of undesirable vehicle motion to generate electrical current in a circuit. The electricity is generated by a power screw that operates like an alternator. Vehicle energy efficiency is increased by using the electrical current to charge a battery. The regenerative damper can be semi-active or passive. The semi-active embodiment is able to adapt to operating conditions to improve vehicle ride and handling, whereas the passive embodiment has a fixed response, regardless of operating conditions.

Abstract: A reference signal generation unit generates a reference signal VCA showing a current limit value with a staircase waveform. A PWM control unit compares a measurement signal SENA obtained by a coil current measurement unit with the reference signal VCA at intervals of a PWM timing signal generated by a PWM timing signal generation unit, and switches transistors of a bridge rectification circuit ON and OFF according to the comparison, thereby PWM controlling a supply current to a coil. A discharge instruction signal generation unit issues a discharge instruction signal MMCPA when the reference signal VCA decreases. In response, a PWM control unit forms a current path in the bridge rectification circuit to cause a regenerative current to flow back into a power supply and capacitor.