Abstract: A motor control center communication system configured to interface with a communication network. The system includes a plurality of motor control units (MCUs), and a MCU controller configured to transmit and receive data signals via the communication network to and from, the plurality of MCUs. Each of the plurality of MCUs includes a magnetic contactor having electrical contacts operable between open and closed positions, and a local control module operatively connected to the associated magnetic contactor and to the MCU controller, and configured to monitor a status of the electrical contacts, transmit the monitored status information to the MCU controller, and actuate the associated magnetic contactor based on data signals received from the MCU controller.

Abstract: According to the present invention, an overcurrent fault detection device includes: an inverter converting DC current to three-phase AC currents for driving a motor; a DC voltage detector; phase current detectors; a rotational position detector that detects a rotational angle of the motor; a control circuit that controls a gate drive circuit, which controls the inverter at every predetermined cycle, based upon the phase current values, a motor rotational angle detection value, and a speed command or a torque command from a higher-order control device; and a first decision-making circuit that detects an overcurrent based upon the phase current values at every predetermined cycle, wherein: the first decision-making circuit determines whether or not the phase current values exceed a predetermined amplitude threshold value by frequency detection for any of the phase current values exceeding the predetermined amplitude threshold value, and determines that an overcurrent has occurred upon detecting the frequency.

Abstract: A portable bearing test device includes a power supply that is operable to supply direct current (DC) electrical power via a plurality of power supply outputs and a circuit common. Independent bearing test circuits are coupled to receive output electrical power from one of the power supply outputs, and are further adapted to independently couple to a separate rotating machine test bearing. Separate indicator lights are electrically coupled in series in each of the independent bearing test circuits.

Abstract: A modular control assembly is provided for on-machine control of a desired machine. One embodiment has a machine mountable base and a replaceable control unit, wherein the machine mountable base has a machine protection device. In various embodiments of the machine mountable base, the machine protection device may have a short-circuit protective device and a disconnect device. In addition, various embodiments of the replaceable control unit may have a variable frequency drive, a soft start device, or an adjustable overload protection device.

Abstract: A permanent magnet machine (PMM) has a kinetic portion electrically coupled to a power conversion portion. Motive power is provided to the kinetic portion by a torque applied to a motive shaft coupled to a prime mover, such as an aircraft engine or an automobile engine. Generated power is transmitted through a plurality of electrically isolated output feeder cables. When a fault is detected, a switch is opened stopping the flow of current through the feeder cable associated with the faulty circuit. The fault condition is then rendered safe while the prime mover may continue normal operation.

Abstract: A compressor monitoring system includes current and voltage monitors, current and voltage averaging modules, a control module, and a switch. The current monitor measures a current drawn by a motor of a compressor. The current averaging module generates first and second average current values based on the current measured by the current monitor. The voltage monitor measures a utility power voltage. The voltage averaging module generates first and second average voltage values based on the voltage measured by the voltage monitor. The control module selectively generates a fault signal when a first ratio is greater than a first predetermined threshold and a second ratio is less than a second predetermined threshold. The first ratio is based on the first and second average current values. The second ratio is based on the first and second average voltage values. The switch deactivates the motor when the fault signal is generated.

Abstract: A shift-by-wire shift switching device and shift switching method that switch a shift range of an automatic transmission using an electric motor. The shift switching device includes a controller that determines whether a fault has occurred in a current supply line of each phase of the electric motor on a phase-by-phase basis, executes an open-loop control of the electric motor using only the phases in which it has been determined that a fault has not occurred, and determines whether a fault has occurred in the current supply line by detecting an activation state of the electric motor when the open-loop control of the electric motor is executed. Therefore, it is possible to determine whether a fault in the motor is a short-circuit fault or a break fault, without addition of a part such as a short-circuit detection sensor.

Abstract: A method of detecting an output phase loss (OPHL) for a motor drive detects an abnormal OPHL operation when at least one phase of a three-phase current is continually zero. Each phase of the three-phase current is acquired, sampled, filtered, and compared. Hence, a corresponding zero-current counter value is continually added, and a corresponding abnormal current value is set as logic 1 when a zero-phase current of the three-phase current is continually zero. Finally, an OPHL certified value is set as logic 1 to confirm that the motor driver is operated in the abnormal OPHL operation. Therefore, a direct-current and an alternating-current OPHL can be detected before and after the motor driver is operated, respectively.

Abstract: A drive amplifier system includes a drive control device, a power supply, and at least one drive amplifier. The power supply includes a power control circuit, a rectifier, and a current sensor. The power control circuit includes an over-current detection circuit, a controller, and a state comparator. The drive amplifier includes a control circuit, a state memory, and an inverting circuit. When a actual current provided for the at least one drive amplifier by the power supply is more than a reference voltage, the over-current detection circuit outputs an over-current detection signal.

Abstract: A controller 43 turns on a semiconductor switch 41 in a normal mode, and turns off the semiconductor switch 41 in a sleep mode. A bypass resistor 5 is connected in parallel to the semiconductor switch 41. A resistance value of the bypass resister 5 is so large as that in the sleep mode, a dark current is supplied to an electronic device 3 via the bypass resistor 5, and if an electric wire downstream of the bypass resistor is short-circuited, an electric current more than a permissive current is prevented from flowing to the electric wire.

Abstract: A control apparatus for controlling a fuel pump includes: an electronic switch provided in a circuit for connecting a power supply to a motor for driving the fuel pump; a current detector which detects a current which flows through the motor; and a controller which controls the electronic switch in a first PWM mode of a first frequency and a first duty ratio in a normal operation; and change a PWM mode to control the electronic switch in a second PWM mode of a second frequency lower than the first frequency and a second duty ratio lower than the first duty ratio when the current flowing through the motor exceeds a threshold current value in the normal operation.

Abstract: Systems and methods for operating a variable speed drive to receive an input AC power at a fixed AC input voltage and frequency and provide an output AC power at a variable voltage and variable frequency. The variable speed drive includes a converter stage to convert the input AC voltage to a boosted DC voltage, a DC link connected to the converter stage to filter and store the boosted DC voltage from the converter stage; and an inverter stage to convert the boosted DC voltage into AC power with variable voltage and the variable frequency. An integral bypass contactor is connected in parallel with the VSD between the AC power source and the AC output power. The integral bypass contactor is arranged to bypass the VSD when the VSD output frequency and voltage are approximately equal with the AC input voltage and frequency.

Abstract: A device for driving a magnetic levitation train has at least one controllable power supply unit that feeds at least one multi-phase power supply line, and a long stator with stator windings that extend in switching sections of the long stator. Each switching section can be connected to at least one of the power supply lines via an assigned section feed switch and each stator winding has at least one assigned current sensor for detecting a current and at least one assigned evaluation unit connected to the sensor. In order to permit a simple, precise overcurrent protection, each current sensor is configured to detect the current in one phase of each assigned stator winding and the evaluation unit is configured to deactivate the section feed switch, if the current detected in each case exceeds a previously defined threshold value.

Abstract: Systems and methods for improved Variable Speed Drives are provided. One embodiment relates to apparatus for common mode and differential mode filtering for motor or compressor bearing protection when operating with Variable Speed Drives, including conducted EMI/RFI input power mains mitigation. Another embodiment relates to a method to extend the synchronous operation of an active converter to the AC mains voltage during complete line dropout. Another embodiment relates to an active converter-based Variable Speed Drive system with Improved Full Speed Efficiency. Another embodiment relates to a liquid- or refrigerant-cooled inductor. The liquid- or refrigerant-cooled inductor may be used in any application where liquid or refrigerant cooling is available and a reduction in size and weight of a magnetic component is desired.

Abstract: A system is provided and may include logic circuitry in communication with an intelligent device. The logic circuitry may process a refrigeration system operating parameter as a function of time and at least one of the logic circuitry and the intelligent device may diagnose a refrigeration system status based on the processing. The intelligent device may output the diagnosis.

Abstract: A current detection device for detecting an electric current flowing through an inverter, an overcurrent level generation device for generating an abnormality judgment reference value, an overcurrent detection device for generating an interruption signal to the inverter on the basis of an output of the current detection device and the abnormality judgment reference value, and an adjusting apparatus for correcting the abnormality judgment reference value of the overcurrent level generation device on the basis of the output at a time when a constant electric current is applied to the current detection device are provided. The overcurrent level generating device is provided with one or a plurality of resistance value adjusting sections, and generates the abnormality judgment reference value in correspondence to a resistance value of the resistance value adjusting section.

Abstract: An electric motor control device includes a power supply unit that supplies power to a three-phase electric motor; a three-phase current sensor that individually detects three respective phase currents of the three-phase electric motor; a summing unit that calculates a three-phase sum by adding the three phase currents detected by the three-phase current sensor; a detected current correction unit that calculates correction amounts for at least two of the three phase currents based on a phase and an amplitude of the three-phase sum and then corrects phase current detection values by the calculated correction amounts; and a motor control unit that controls a power supply by the power supply unit to the three-phase electric motor by feedback control based on the three phase currents after correction by the detected current correction unit and on target currents.

Abstract: An inverter system having a semiconductor device, and a railway vehicle using this inverter, provide a more accurate determination of whether an abnormal heat generation from the inverter is associated with an error of the inverter system or is due to other causes, by use of a plurality of temperature detecting elements at a plurality of sites associated with the semiconductor device. An error detection section applies inputs from the temperature detecting elements, captures a trend of the differential value based on the plurality of temperature inputs using period sampling wherein an error associated with the semiconductor device, and not from some other condition such as outside environment temperature, is determined based on differences from, or a change in, the initial trend.

Abstract: A dual redundant permanent magnet type dynamoelectric machine includes a dual flux throttle system to selectively disable one of a first motor and a second motor.

Abstract: The present invention refers to an electric overload protecting device (100) capable of avoid overheating of motors (400) of refrigeration equipment, and further providing an additional protection at the end of its lifetime. Such additional protection is provided by means of a backup protecting element (300) comprising at least a first connection means (301) associable to an electric energy feeding source (600); a second connection means (302) associable to the motor (400); and a fusing linkage (303) directly connecting the first connection means (301) to the second connection means (302). Such fusing linkage (303) is capable of interrupting an electric current that runs through the motor (400). The first connection means (301), the second connection means (302) and the fusing linkage (303) are fully associated to each other in a single part. The present invention refers also to a motor start device (500) comprising the above mentioned overload protecting device (100).

Abstract: In a system comprising a fuel and a rotating electrical machine, damage of a switching element is prevented when the rotating electrical machine becomes a locked state. In a power controller, it is monitored whether the rotating electrical machine is in the locked state or not. When the rotating electrical machines is judged to be in the locked state, a command for dropping output voltage is given to the fuel cell. Thus, inverter input voltage can be dropped, loss power of the switching element in the rotating electrical machine is dropped and damage can be suppressed. The rotating electrical machine is monitored to cancel the locked state or not while dropping of inverter input voltage is controlled. When the locked state is judged to be canceled, control of the fuel cell is returned to a state of regular operation control.

Abstract: The following invention is an electromechanical system (1) that is to be connected to an electricity supply (7), comprising: an electric machine (2) that can operate as an independent generator with a rotating shaft, and a switching system (9) allowing i) in the first configuration, the electric machine to operate as a motor in the case where the connected device (4) is normally driven or as a generator in the case where the coupled device is normally driving, and ii) in the second configuration, the electric machine to operate as an independent generator, the electrical energy generated by the electric machine (2; 22) being dissipated in the machine and in a dissipative load (13).

Abstract: A protection circuit is configured to change control modes in a drive control process of a drive circuit for a motor when overvoltage is applied to a power source line while the motor is driven. With overvoltage applied, the control process is changed to a control mode to perform forced commutation control. When a predetermined time period passes after the voltage of the power source line returns to a predetermined level, the control process is changed to a sensorless control mode using a position detection circuit. This configuration can provide a motor drive apparatus capable of performing an overvoltage protection operation appropriately even when the sensorless control mode is adopted.

Abstract: A motor drive device includes: chopping signal generation means for generating a chopping signal Sa when drive current of a driver has reached a first threshold value; chopping signal cut-off means for cutting off the chopping signal Sa when the drive current has reached a second threshold value which is greater than the first threshold value; and overcurrent protection means for generating an overcurrent protection signal Se when the drive current has reached a third threshold value which is greater than the first threshold value and its continuation time has reached a predetermined threshold value time. Thus it is possible to simultaneously obtain the constant current chopping function and the overcurrent protection function and to improve its reliability and safety.

Abstract: A terminator reduces reflections on power lines connecting an inverter to an AC motor by providing a differential-mode reflection damping element and at least one common-mode reflection damping element, the latter including a series capacitance to substantially reduce power dissipation in the resistance of the damping elements.

Abstract: A method of controlling in-rush current to a DC motor is disclosed. The method may include operating the DC motor in a first mode including applying back-EMF across a relay coil to maintain the relay in an open configuration when the back-EMF is below a predetermined voltage. The method may also include operating the DC motor in a second mode including applying the back-EMF across the relay coil to maintain the relay in a closed configuration when the back-EMF is equal to or above the predetermined voltage.

Abstract: A motor-drive circuit comprising: a current-passage-control circuit to perform ON/OFF control of a drive transistor connected to a motor coil to pass current through the motor coil; an overcurrent-state-detection circuit to detect whether current passing through the drive transistor is in an overcurrent state where the current exceeds a predetermined threshold value; a charging and discharging circuit to start charging a capacitor in response to detecting the overcurrent state by the overcurrent-state-detection circuit and subsequently discharge the capacitor in response to not detecting the overcurrent state; and an overcurrent-protection-control circuit to stop the ON/OFF control to turn off the drive transistor, for an elapsed charging period for a charging voltage of the capacitor at a predetermined voltage to exceed a threshold voltage, and determine whether to perform such an overcurrent-protection-control as to turn off the drive transistor by detection of the overcurrent state, after the charging peri

Abstract: A drive system for an electrical machine is provided. The system includes a control unit and a monitoring unit, which is independent of the control unit. The control unit includes a device that converts one or more incoming operating parameters of the electrical machine to an output value. The monitoring unit includes a device that converts the operating parameters to a comparison value, with the conversion being carried out more quickly in the control unit than in the monitoring unit. A comparator compares the output value or an intermediate value of the output value with the comparison value of the output value or of the intermediate value.

Abstract: In a motor controller, if a failed electric current flow in any one of phases of a motor is detected, a motor control signal is generated, based on a phase other than the phase with the failed electric current flow, in such a manner that a motor electric current matches a required torque except for at a specific rotation angle corresponding to the phase with the failed electric current flow.

Abstract: A method of voltage supply management for an electric drive system includes receiving a voltage signal (1002) indicative of a voltage in a supply link, and one or more condition signals that are indicative of an operating condition of the electric drive system. A difference between a desired voltage value (1008), which is calculated based on the voltage signal (1002) and the one or more condition signals, and the voltage signal (1002) yields a voltage error signal (1014). The voltage error signal (1014) is evaluated to indicate an over-voltage condition or an under-voltage condition. Power is dissipated from the supply link when an over-voltage condition is present and a torque command limit with respect to the one or more electric drive motors (210) is imposed when an under-voltage condition is present.

Abstract: A method for controlling a motor (2) which drives a disk-shaped tool (4) of a power tool (1) and to which a motor voltage in the amount of a nominal value is applied in an “on” position of a motor switch (6), includes determination of an actual motor current (IM) applied to the motor (2) and comparing it to a first predetermined threshold (GW1), and automatically triggering of a control process for protecting the motor (2) when an overload condition which is defined in that the first predetermined threshold (GW1) is exceeded beyond a first predetermined limiting time period (grDt1), is met, the control process including reduction of the motor voltage applied to the motor (2) by a magnitude that can be perceived by the user as a choke value.

Abstract: A current sensor of a motor controller detects the current applied to a motor drive circuit and thus a phase where a failure cannot be detected would occur without taking any measures. However, an abnormal current monitor section contained in a microcomputer receives a voltage signal of an average value of the currents detected in the current sensor by allowing a signal to pass through a first LPF having a cutoff frequency sufficiently lower than the frequency of a PWM signal. Therefore, whether or not the value is within a predetermined normal range is checked, whereby whether or not some failure containing a failure of the current sensor occurs can be easily determined about every phase.

Abstract: An over-current protection circuit, has a main transmission circuit including at least a first triode and a first resistor, a trigger circuit including a second triode and a second resistor, and a detecting circuit having an input terminal and an output terminal. One end of the first resistor is connected to one end of a collecting electrode and an emitting electrode of the first triode. The other end of the first resistor is connected to a current output. The other end of the collecting electrode and the emitting electrode of the first triode is connected to a current input. One end of the second resistor is connected to a collecting electrode of the second triode. The other end of the second resistor is connected to the ground. An emitting electrode of the second triode is connected to the current input. The collecting electrode of the second triode is connected to a base electrode of the first triode.

Abstract: A surge current protection circuit, has a control unit having an output end, a photoelectric coupling and driving circuit, a silicon symmetrical switch having a control end, and a current-limiting resistor. The current-limiting resistor and the silicon symmetrical switch are parallel connected altogether and then serially connected to a load and an AC input, and the control end of the silicon symmetrical switch is connected to the output end of the control unit via the photoelectric coupling and driving circuit. The invention features low production cost, high reliability and improved power efficiency, and is capable of effectively suppressing surge current.

Abstract: To provide a cordless power tool which can suppress heat generation of a protection unit and prevent the erroneous operation. A cordless power tool 1 includes a body casing 10; a battery 20 which is detachably attached to the body casing 10 and can supply electric power; a motor 30 which is housed in the body casing 10, and generates rotation force by the electric power of the battery 20; a cooling fan 40 which rotates by the rotation force of the motor 30; and a protection unit 50 which shuts off the power supply to the motor 30, in accordance with a detection result of the state of the battery 20, so that the battery 20 does not enter an overdischarge state or an overcurrent state. Herein, a passage of cool air generated by the cooling fan 40 is formed in the body casing 10, and the 16 protection unit 50 is arranged so that at least its part is located in the passage of the cool air.

Abstract: A motor overload protecting method includes (a) detecting an instantaneous motor current value in real-time, calculating a current integral value in each of a corresponding integral period, and resetting the current integral value to 0 at an end of the integral period, (b) obtaining an overload coefficient according to the current integral value, which is greater than or equal to 0 and less than 1 when the current integral value is greater than or equal to a maximum motor current value, and is equal to 1 when the current integral value is less than the maximum motor current value, wherein the maximum motor current value is a maximum current integral value when the motor is in a non-overload condition; and (c) multiplying the instantaneous motor current value by the overload coefficient to obtain a new input current value, and operating the motor according to the new input current value.

Abstract: This invention provides methods for electric vehicle motor control and rotor position detection and fault-tolerant processing. The rotor position signal sampled by the system is compared with the previous rotor position ?0. When there is a sudden change, the current position signal acquired is discarded. Instead, a fault-tolerant processing strategy for use during an error condition is employed where the previous sampled rotor position ?0 is used as a base to determine the corrected current rotor position angle ?1?. Then the correcting value is used to control the electric motor.

Abstract: A method and apparatus for a pump control system. One or more embodiments of the invention include a pump controller that can perform a self-calibrating procedure, can provide precise motor speed control, can provide a limp mode before shutting down the motor when system parameters are exceeded and/or fault conditions occur, can detect fault conditions, and can store fault conditions for later retrieval.

Abstract: In an off-road vehicle having a resistor grid network and a blower system as part of a braking system operable to determine at least one of a resistor failure and a blower failure, the system including a first series of resistors connected in series, a second series of resistors connected in series, a blower cross to at least one of the first series of resistors and the second series of resistors, a sensor proximate at least one of the first series of resistors, the second series of resistors, and the blower, wherein each individual resistor in the first series connected in parallel to an individual resistor in the second series, and wherein when at least one of a current value, blower speed, and voltage value changes, the grid network is disconnected.

Abstract: A motor detecting and protecting apparatus electrically connected with a motor. The motor detecting and protecting apparatus includes a detecting unit, an error determining unit, a controlling unit and a driving unit. The detecting unit detects a state of the motor and outputs at least one first detecting signal and at least one second detecting signal to the error determining unit. The error determining unit has a first predetermined value, wherein the error determining unit outputs a warning signal to the controlling unit while a variation value between the first detecting signal and the second detecting signal exceeds the first predetermined value. And the controlling unit will control the motor to stop operating by the driving unit in accordance with the warning signal. And a motor detecting and protecting method is also disclosed.

Abstract: Each of three-phase arm of an inverter has first and second switching elements connected in series together at a connection point to the corresponding phase coil of the three-phase motor. Control device turns on the first switching element of the i-th (i is a natural number smaller than four) for a predetermined time period, and determines that the second switching element of the i-th arm has a short fault, when an overcurrent exceeding a predetermined threshold is detected within the predetermined time period. The predetermined time period is shorter than a time period from a time point of turning on the first switching element of the i-th arm to a time point of attaining the predetermined threshold by a current flowing through a path extending from a power supply line through the second switching element of the remaining arm other than the i-th arm to a ground line.

Abstract: A motor lock detection circuit for detecting lock of a motor, comprising: a binarizing circuit to binarize a signal, obtained from the motor, having a frequency corresponding to rotation speed of the motor, to generate a binary signal; an edge detecting circuit to generate an edge detection signal when detecting an edge of the binary signal; a first counter to count based on a first counter clock, be reset according to the edge detection signal generated by the edge detecting circuit, and generate a count signal when counting for a first count period longer than an interval between edges of the binary signal; and a second counter to count based on a second counter clock, be reset according to the count signal, and generate a motor lock detection signal indicative of detection of lock of the motor when counting for a second count period longer than the first count period.

Abstract: A method (100) is provided for controlling torque of an electric motor (12) including the step (106) of supplying drive current to drive the electric motor. The speed of the electric motor is monitored (108) and from the monitored speed, it is determined (110) when the motor has reached a steady state condition. The supply current is turned off (118) if the monitored torque of the electric motor exceeds a predetermined value (114) after the electric motor has reached the steady state condition.

Abstract: An accurate slip calculation for providing monitoring and protection to an electric motor. The slip calculation is made using a minimum value of stator resistance as the initial stator resistance, where the minimum value of stator resistance is the minimum value of stator resistance calculated during an initiation period of the motor. The initiation period may be a predetermined time period or a predetermined number of cycles during the motor startup. The initiation period may start after a predetermined settling time or after a predetermined condition is met.

Abstract: An electric vehicle includes a control unit having overcurrent generation judgment unit, inverter selection unit, and inverter drive control unit. The overcurrent generation judgment unit judges whether an overcurrent is generated in an inverter for generation or an inverter for travel. When an overcurrent is generated in one of the inverters, the inverter selection unit selects the other inverter to be driven. The inverter drive control unit stops the driving of the one inverter and drives the other inverter to drive a travel motor or a generator.

Abstract: A drive arrangement for a hand-guided working machine for agriculture, forestry and horticulture applications. The drive arrangement comprises an electric motor, a DC power source for electrical energy, and a control apparatus for the electric motor which is fed from the DC power source. The electric motor has a specific, in particular linear, characteristic curve between the electric current which is consumed by the electric motor and the rotational speed of an output shaft of the electric motor. The control apparatus has current-limiter which limits the current which flows through the electric motor to a maximum value in order to protect the electric motor against overloading. The control apparatus limits the current consumption of the electric motor in a range of low rotational speeds to values which are considerably smaller than the characteristic curve values which are given for these rotational speeds by the characteristic curve of the electric motor, as a function of the rotational speed.

Abstract: A diagnostic system and method for a compressor assembly including a compressor and a motor protector includes logic circuitry associated with the motor protector and operable to analyze a status of the motor protector as a function of time and identify a specific fault cause. The diagnostic system also includes a demand signal sensor and a current sensor, wherein the logic circuitry is associated with the sensors to further enable the diagnostic system to determine a specific fault cause.

Abstract: Embodiments of the invention provide a stand-alone controller and a method for controlling a pump motor driven by an alternating current source. The stand-alone controller includes a power terminal for connection with the alternating current source and a load terminal for connection with the pump motor. The stand-alone controller further includes an enable switch to form a power line carrying power from the alternating current source to the pump motor. The stand-alone controller can store a first current being drawn through the power line by the pump motor when a control switch is actuated. A state of the enable switch is based on a comparison of the first current to a second current being drawn through the power line by the pump motor.

Abstract: A switching system is provided. The switching system includes electromechanical switching circuitry, such as a micro-electromechanical system switching circuitry. The system may further include solid state switching circuitry coupled in a parallel circuit with the electromechanical switching circuitry, and a controller coupled to the electromechanical switching circuitry and the solid state switching circuitry. The controller may be configured to perform selective switching of a load current between the electromechanical switching circuitry and the solid state switching circuitry in response to a load current condition appropriate to an operational capability of a respective one of the switching circuitries.

Abstract: When a variable valve mechanism which varies an opening characteristic of an engine valve is malfunctioned, the power supply to a drive circuit for the variable valve mechanism is stopped, and also a control signal to the drive circuit is cleared.