Abstract: A door operator with an electrical back check feature is disclosed. Embodiments of the present invention are realized by a motorized door operator that electrically creates a back check force for an opening door. The door operator simulates the back check normally created by hydraulic means in convention door closers, but without the use of pistons, springs or hydraulic fluid. The door operator includes a motor disposed to operatively connect to a door so that the door will open when the motor moves, and a position sensor to determine a position of the door. A processor is programmed to exert a closing force on the door in the back check region. In some embodiments, the closing force is exerted by injecting a voltage into the electric motor of the door operator.

Abstract: A method of braking a washing machine from an operational speed to a reduced non-zero speed is provided (as well as a washing machine incorporating the method) for a washing machine driven by one of a synchronous or asynchronous motor. Upon receipt of a speed reduction signal, the motor rotating magnetic fields are collapsed for a defined time period. After the defined time period, DC braking voltage is applied to the motor stator windings at a controlled ramp-up rate to an amplitude to generate a controlled ramped braking torque on the motor until the motor has slowed to a defined reduced speed. Thereafter, the amplitude of the DC braking voltage is set to 0V and the motor is soft started to an amplitude and reduced frequency needed to maintain the defined reduced speed.

Abstract: The present invention advantageously provides methods for manually and/or remotely controlling a motorized roller shade that includes a shade attached to a shade tube, a DC gear motor disposed within the shade tube and a microcontroller. One method includes detecting a manual movement of the shade using a sensor, determining a displacement associated with the manual movement, and, if the displacement is less than a maximum displacement, moving the shade to a different position by energizing the DC gear motor to rotate the shade tube. Another method includes receiving a command from a remote control, and moving the shade to a position associated with the command by energizing the DC gear motor to rotate the shade tube.

Abstract: A fan control system includes first and second adjacent fans, first and second motors configured to rotate the first and second fans, and a control unit configured to control rotational speeds of the first and second motors in order to control rotational speeds of the first and second fans. The first and second motors are energized such that the rotational speeds of the first and second fans reach target rotational speeds prior to increasing the rotational speeds of the first and second fans to required rotational speeds. The target rotational speeds are lower than the required rotational speeds. The first and second motors are energized such that the rotational speeds of the first and second fans reach the required rotational speeds after the rotational speeds of the first and second fans reach the target rotational speeds.

Abstract: An apparatus for controlling a stepper motor comprises a driver circuit and a brake circuit each having a motor controller device. The driver circuit, brake circuit and motor are connected in parallel. The driver circuit receives an enabling signal and outputs driver current to the motor accordingly. The brake circuit includes a logic circuit which receives the enabling signal, a brake input signal, and a power supply status signal, and outputs a brake logic signal. The brake circuit motor controller device is coupled to the logic circuit. This motor controller device receives an output of the brake logic circuit and outputs braking current to the motor in accordance therewith. The braking circuit is effective to prevent movement of the motor shaft in accordance with output of the braking current. The motor controller devices are substantially identical. The apparatus is effective to control the motor while avoiding generation of RF noise.

Abstract: The invention relates to a retraction device for a movable piece of furniture, having a pulling means windable on a roll, and an electric motor is provided for driving the roll. The retraction device also has a coupling for releasably connecting the movable piece of furniture to the electric drive, and the coupling has a first coupling part for fastening to the movable piece of furniture and a second coupling part connected to the pulling means. The first coupling part has an opening for at least the partial acceptance of the second coupling part. A locking mechanism is provided by which the first coupling part can be connected to the second coupling part in at least two different positions, and the second coupling part is located at different depths in the opening in the two different positions.

Abstract: Presented is a system for synchronizing movement of roller shades each from a first position to a common second position. The system includes a master controller, a plurality of optical assemblies each configured to obtain information related to the position of one of the roller shades, and a plurality of motor assemblies. Each of the motor assemblies is configured for receiving the position information from one of the plurality of optical assemblies, receiving a master shade movement time from the master controller, and moving one of the of roller shades from the first position to the common second position in response to the received position information so that the roller shade arrives at the common second position simultaneously with the other roller shades in a time equal to the master shade movement time.

Abstract: Presented is a method for synchronizing movement of a plurality of roller shades each disposed at a first position to a common second position. The method includes obtaining information related to the position of each of the plurality of roller shades with a respective one of a plurality of optical assemblies, and moving each of the plurality of roller shades from the first position to the common second position in response to the respective obtained position information so that each of the plurality of roller shades arrives at the common second position at the same time.

Abstract: A system for detecting a backspin condition of a motor in an electrical submersible pump is described herein. The system comprises a variable speed drive for powering the motor via a power cable; and a controller, the controller having a memory, a computer processor, and a computer program product stored on the memory and executable by the processor. The computer program product comprises the instructions of: monitoring an input current or impedance on the power cable to determine changes in motor current impedance, comparing changes in the motor current impedance to a historical threshold value for backspin events to determine whether the motor is backspinning; impeding operable power to the motor when it is determined the motor is backspinning; supplying a low AC voltage to the motor after it is determined the motor is backspinning; and determining whether or not the motor has stopped backspinning by monitoring the low AC voltage.

Abstract: Systems, methods and apparatus are provided through which in some multisensory implementations, a patient-lifting-device is controlled by voice recognition using a background noise filter, keyboard text input, synaptic control and/or a tongue tactile input commands. In some implementations, the command is rejected or accepted in reference to an analysis of the command, the analysis including an analysis of the authority of operator, competency and/or the state of mind of the operator.

Abstract: A motor control apparatus for controlling a DC motor includes a detection unit configured to detect an angular speed of the DC motor, and a control unit configured to, when the DC motor is accelerated, increase a control value that controls a driving of the DC motor at a constant rate from a first control value corresponding to an angular speed lower than a target angular speed up to a second control value corresponding to an angular speed higher than the target angular speed, and switch the control value that controls the driving of the DC motor to a control value corresponding to the target angular speed in response to the detection result of the detection unit reaching the target angular speed.

Abstract: The present invention advantageously provides a motorized roller shade that includes a shade tube, a motor/controller unit and a power supply unit. The motor/controller unit is disposed within the shade tube, and includes a bearing, rotatably coupled to a support shaft, and a DC gear motor. The output shaft of the DC gear motor is coupled to the support shaft such that the output shaft and the support shaft do not rotate when the support shaft is attached to the mounting bracket.

Abstract: A method of driving a vibration wave motor enables proper frequency control of an AC voltage applied to the motor according to the rotational speed difference between the actual and target rotational speeds of the motor, even if frequency-rotational speed characteristics are not stored in advance. A target rotational speed of a moving member is set. A ratio of an amount of increase or decrease in a rotational speed of the moving member to an amount of update of a frequency of the AC voltage and a rotational speed difference between the target rotational speed and an actual rotational speed of the moving member are calculated. The amount of update of the frequency is calculated by dividing the calculated rotational speed difference by the calculated ratio. The frequency of the AC voltage is updated by using the calculated amount of update of the frequency.

Abstract: A stepping motor controlling device includes first and second clock signal generators, plural drivers, and a controller. The first clock signal generator generates a reference clock signal for rotationally driving of plural stepping motors. The second clock signal generator generates, on the basis of the reference clock signal, for each of the stepping motors, speed control clock signals. The plural drivers are provided respectively for the stepping motors and, on the basis of the speed control clock signals for the respective stepping motors, generate pulse excitation signals and input the pulse excitation signals to the stepping motors to rotationally drive the stepping motors. The controller controls the second clock signal generator to generate the speed control clock signals such that phases of the respective speed control clock signals for the stepping motors differ from one another.

Abstract: An object of the present invention is to provide a motive power output apparatus including a motor with a permanent magnet and a motor without a permanent magnet. A boost device (10) is connected to a power storage device (B). A first drive device (30) is connected to the boost device (10). A first rotating electric machine (35) with a permanent magnet is connected to the first drive device (30). A second drive device (40) is connected to the power storage device (B). A second rotating electric machine (45) without a permanent magnet is connected to the second drive device (40). A third drive device (20) is connected in parallel to the first drive device (30). A third rotating electric machine (25) with a permanent magnet is connected to the third drive device (20). The second rotating electric machine (45) is formed of a reluctance motor or an induction motor. The first rotating electric machine (35) and the second rotating electric machine (45) of the present invention may be linked to wheels of a vehicle.

Abstract: A model train control system providing a more realistic modeling of the movement, sound, smoke, and lighting effects of a model train is disclosed. A number of dynamic inputs are used to control such effects. Novel features include providing a dynamic variable speed compensator, a dynamic engine load calculator, automatic dynamic momentum, an adjustable train brake, spectrum control, a velocity controller, pressure sensitive effects, a voice activated dispatcher system, a train location and information reporter network, two digit addressing, a traffic control system, accessory control, a model train Central Control Module, and removable memory modules.

Abstract: An automated gas cap mechanism for opening and closing the fuel tank of a vehicle includes a housing with a filler compartment door mounted on a door support link that is coupled to an axle having first and second ends mounted in slots formed in the housing and configured to rotate and to move longitudinally in the housing. A crank is mounted on the axle and an arm on the crank is pivotally coupled to the door support link. A drive motor is operable to rotate the axle and crank to retract the filler compartment door into the housing and drive the axle in a linear direction to open a gas cap coupled to the axle.

Abstract: An integrated printed circuit board-based solid state line voltage interface for use in automation control system applications. Relays connect various functional loads to the line level source in response to input from a controller unit. Switches enable a user to override the controller and manually control the connection of the functional loads. An alternative embodiment further includes limit switches and time delays. The compact nature of the device facilitates ease of installation, mounting of multiple units in less space, and mounting in various specialized location as desired.

Abstract: The model train control system includes a remote control device that receives user input with respect to various train functions such as desired speed and effects, and that generates commands based on that input in order to cause the model train to perform in a desired manner. In an embodiment of the invention, the model train controller comprises control input devices that permit user control over corresponding control features of the model train. A touch screen display may be coupled to the housing and adapted to receive user selections regarding the control features. A processor is operatively coupled to the control input devices and the touch screen display. The processor is adapted to generate at least one model train command to be transmitted to the model train based at least in part on a user input received from either one of the control input devices or the touch screen display.

Abstract: The present invention pertains to vibration devices that do not require a rotating mass. In accordance with aspects of the invention, a coil causes a plunger to move linearly. A spring device is coupled to one end of the plunger. Activation of the coil causes the plunger to move in a first direction relative to a body and coil deactivation enables the spring device to move the plunger in an opposite direction relative to the body. Activating the coil at a predetermined frequency causes vibration of the plunger. Vibratory forces are transferred via the spring device and coil onto the body at predetermined locations. Opposing spring devices may be affixed to either end of the plunger. Spring devices may be linear or non-linear. Such spring devices may be used in conjunction with magnetic spring devices. A controller and a driver circuit may be used to control system operation.

Abstract: A method and apparatus for controlling a plurality of different motors used in a corresponding plurality of power tool applications requiring different operational characteristics. In one implementation a method involves the use of a single universal control module to store a generic, non-application-specific control algorithm. The generic, non-application-specific control algorithm has at least one programmable constant. The programmable constant is selected to transform the generic, non-application-specific control algorithm into an application-specific control algorithm. The programmable constant represents a function parameter relating to a specific functionality of a specific, selected motor used in a specific, selected motor application to implement a phase control over the specific, selected motor.

Abstract: A semiconductor power converter includes a power converter for converting direct current to three-phase alternating current or vice versa; a means for detecting a current in an alternating current side of the power converter; a means for providing a current reference in the alternating current side of the power converter; a current controller for calculating a voltage reference in the alternating current side of the power converter to match the current reference and a value of the detected current; and a pulse width modulation means for controlling the power converter through pulse width modulation based on the voltage reference, wherein the current reference is used in place of the value of the detected current for at least one phase current among three phase currents in the alternating current side.

Abstract: A control system for controlling an adjustment device which is operated by electric motor in a motor vehicle includes an indirect anti-trapping system for detecting a trapping situation between an adjustment element, which is moved by the adjustment device in an adjustment movement along an adjustment path, and a vehicle element. The anti-trapping system stops or reverses the adjustment movement of the adjustment element if a defined threshold value for a mechanical running parameter—which results from the adjustment movement is exceeded. The anti-trapping system operates with an analysis unit for analyzing the adjustment movement of the adjustment element, wherein the control system is configured and embodied in such a way that by means of the analysis unit, in an analysis mode, the running parameters of the adjustment device can be checked for mechanical functional faults of the adjustment device.

Abstract: A method for controlling the operation of a motor utilizing a generic motor control module. The method includes sampling at least one motor operating criterion during operation of the motor and executing a generic control algorithm at a predetermined periodic interval. Execution of the algorithm provides a firing angle, duty cycle, or other suitable control function solution for an electronic valve for each periodic interval, thereby controlling the behavior of the motor. Additionally, the method includes firing the electronic valve at the calculated timing during each periodic interval such that the motor functions in accordance with desired motor operational parameters.

Abstract: A voltage command value of a converter is set by executing the step of determining a candidate voltage of a system voltage VH as a converter output voltage in a voltage range from the minimum necessary voltage corresponding to induction voltage of a motor generator and a maximum output voltage of the converter; the step of estimating power loss at the battery, converter, inverter and motor generator, at each candidate voltage, and calculating total sum of estimated power loss of the overall system; and the step of setting the voltage command value VH# based on the candidate voltage that minimizes the total sum of estimated power losses among the candidate voltages.

Abstract: A method for controlling the operation of a motor utilizing a generic motor control module. The method includes sampling at least one motor operating criterion during operation of the motor and executing a generic control algorithm at a predetermined periodic interval. Execution of the algorithm provides a firing angle, duty cycle, or other suitable control function solution for an electronic valve for each periodic interval, thereby controlling the behavior of the motor. Additionally, the method includes firing the electronic valve at the calculated timing during each periodic interval such that the motor functions in accordance with desired motor operational parameters.

Abstract: A device and method for controlling the changing operation of an on-load tap changer (LTC) that interrupts current passing the current zero point of a commercial frequency are provided. The device may include a current zero point detecting unit that detects a zero point in the waveform of current passed through the LTC, a current zero point cycle measuring unit that measures the cycle of the current zero point detected by the current zero point detecting unit, a commercial frequency determining unit that generates an output signal when the cycle of the current zero point measured by the current zero point cycle measuring unit corresponds to a commercial frequency, and an actuation signal output unit that outputs an actuation signal used to have the LTC carry out tap changing operation in response to the output signal of the commercial frequency cycle determining unit.

Abstract: Embodiments of the invention provide a disk device and a method of controlling the device which is capable of suppressing peak current, even for serial communication, that is required when initiating rotation of a spindle motor down to a level equivalent to that of parallel communication, without prolonging elapsed time before reaching the steady rotation speed. In one embodiment, an HDD includes a serial communication circuit which executes serial communication with a host, an SPM which rotates a disk, an HDC/MPU which controls the SPM and the serial communication circuit. The HDC/MPU, after shutting down the serial communication circuit once, starts up the serial communication circuit again when rotation speed of the SPM reached the specified standard value, and establishes serial communication with the host by means of the serial communication circuit.

Abstract: A fan motor drive control apparatus comprises a plurality of drive circuits for driving respectively a plurality of fan motors, and a speed change-over control circuit for transmitting a control signal for changing over speeds of the fan motors, to the plurality of the drive circuits, wherein each of the drive circuit comprises a stopping detection terminal for detecting stopping of a fan motor as an object to be driven, and the speed change-over control circuit transmits the control signal in accordance with a signal received from the stopping detection terminal.

Abstract: A semiconductor power converter includes a power converter for converting direct current to three-phase alternating current or vice versa; a means for detecting a current in an alternating current side of the power converter; a means for providing a current reference in the alternating current side of the power converter; a current controller for calculating a voltage reference in the alternating current side of the power converter to match the current reference and a value of the detected current; and a pulse width modulation means for controlling the power converter through pulse width modulation based on the voltage reference, wherein the current reference is used in place of the value of the detected current for at least one phase current among three phase currents in the alternating current side.

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

Abstract: Information indicative of the placement of spindle motor components may be obtained and used to provide a correction to one or more BEMF-derived attributes used to control the spindle speed. In some implementations, first and second signals indicative of BEMF of different stator windings may be used to determine a speed-related characteristic. The speed related characteristic may be used to determine an error amount, which may be used to determine a correction factor to control the speed of the spindle motor.

Abstract: A method is specified for operating a rotating electrical machine (1), which machine (1) has at least two sets of stator windings (A, B), in each case one associated converter unit (2) being provided for each set of stator windings (A, B) and each set of stator windings (A, B) comprising n phase windings, where n?3, in which method the respective set of stator windings (A, B) is fed by the associated converter unit (2).

Abstract: A self-calibrating, continuous variable speed fan for use in cooling electronic circuitry is disclosed. Upon initial power-up, in an environment of known temperature, the self-calibrating fan accommodates for the tolerances of its electronic components by reading a voltage from its thermistor array and comparing the actual value to an expected value for the given temperature. The difference is then stored in the non-volatile memory of a microcontroller for use in adjusting future voltage readings from the thermistor array. During normal operation, adjusted readings from the thermistor array are then converted by the microcontroller into a control signal for driving the motor of a cooling fan. A quickly cycling stochastic process between adjustments to fan motor speed and temperature readings is then established, thereby maintaining a high degree of control over the device to be cooled.

Abstract: Rotation of a capstan motor is detected by a frequency detector, and supplied to a CPU as a rotation detection signal CFG. The CPU derives a period of the rotation detection signal CFG, calculates an average rotational speed of the capstan motor on the basis of the derived period, derives an attenuation value of the rotational speed on the basis of the calculated average speed, and thereby sets a braking time interval. As a result, calculation of the braking time using a highly accurate zero point detection with a frequency detector of one system becomes possible. The apparatus scale can be reduced.

Abstract: A method for controlling the operation of a motor utilizing a universal motor control module. The method includes sampling at least one motor operating criterion during operation of the motor and executing a universal control algorithm at a predetermined periodic interval of an AC line signal. Execution of the algorithm provides a firing angle solution for an electronic valve for each periodic interval, thereby controlling the behavior of the motor. Additionally, the method includes firing the electronic valve at the calculated firing angle during each periodic interval such that the motor functions in accordance with desired operational parameters.

Abstract: The present invention discloses an apparatus for compensating for a speed error of a motor which can reduce a speed ripple of the motor resulting from load characteristics, and which also can reduce vibrations and noises. The apparatus for compensating for the speed error of the motor divides a rotational section corresponding to one complete revolution of a rotor of the motor into a plurality of preset rotational sections, determines a speed compensation value in each divided rotational section on the basis of a difference value between a reference speed and a previous estimated speed, and compensates for the speed error of the motor on the basis of the speed compensation value.

Abstract: In a motor and a disk drive apparatus in accordance with the present invention, a position detecting part 30 comprises a detection signal switching circuit 39A, a noise elimination circuit 38 and a detection circuit 39B, and the detection signal switching circuit 39A is configured to output an inverted detection signal obtained by logically inverting a detection signal until the rotation speed reaches a predetermined rotation speed after the beginning of starting or until a position detection pulse signal FG is detected a predetermined number of times; position detection operation is carried out only during the ON operation of PWM, whereby PWM sensorless starting is carried out.

Abstract: A method controls a torque of an a. c. motor which does not cause a shortage of torque by using an economical current detection which estimates d- and q-axis currents Idc, Iqc from d. c. current IDC flowing through an input d. c. bus line of a power converter. A value of d- and q-axis motor currents Id, Iq of a rotational coordinate system are estimated from detected input d. c. current IDC flowing through the bus line of the power converter to which power is input from a d. c. power source 21. A output voltages of the power converter 2 are controlled so that the estimated currents Idc, Iqc are equal to respective current instruction values Id*, Iq*. Errors of motor constants are determined from information on the motor currents and the rotational phase errors by an operation.

Abstract: A control system for a polyphase AC motor having a predetermined horsepower rating is provided comprising a plurality of integrated control systems each rated at less than the hoursepower rating for the motor and having a rectifier section, an inverter section, and a controller section, and a parallel controller interfaced to each integrated control system.

Abstract: A controller of a vehicle for igniting, i.e., starting-up an engine on the basis of a load condition. When a starting condition judging device judges that the vehicle is advanced, i.e., starts moving, during an idle stop, an engine water temperature detector and a lubricating oil temperature detector of a load condition detector detect, e.g., the water temperature of the engine and the temperature of lubricating oil of an automatic speed change gear as a load condition having an influence on the magnitude of the load torque given to a motor. When an ignition condition setting device sets an ignition condition for starting the engine on the basis of the load condition and an ignition condition judging device judges that the ignition condition occurs, an engine ignition device ignites the engine. Thus, when the load with respect to the motor is large, the engine is ignited from low speed rotation and electric power consumption is reduced.

Abstract: The invention relates to a windshield wiper system with two wipers (1, 2) that travel in opposite directions and can each be driven by a separate motor (MFS, MBS), wherein a regulating unit (7) is provided for triggering the motors (MFS, MBS) separately from each other by means of control signals, wherein the regulating unit (7) triggers the motors (MFS, MBS) of the wipers (1, 2) in order to preset a time-dependent angular position of the wipers according to a trigonometric function ?(t).

Abstract: A movable barrier operator (10) can have at least two automatic modes of operation. These modes of operation can differ from one another at least with respect to their respective utilized maximum-applied-force thresholds, such that one of the modes of operation correlates to a reduced maximum-applied-force threshold. Selection between these available maximum-applied-force thresholds can be based, at least in part, upon whether an obstacle detector is operably coupled to the movable barrier operator. In one embodiment, a primary controller (30) and a secondary controller (31) can be utilized to effect the controlled selection and usage of the available maximum-applied-force thresholds. In another embodiment, maximum permitted speed of travel for the movable barrier can also be determined, at least in part, as a function of whether an obstacle detector is available to the movable barrier operator.

Abstract: An anti-entrapment system for preventing an object from being entrapped by a translating device includes a capacitance sensor positioned adjacent to the translating device. The sensor has first and second flexible conductors separated by a separation distance. The conductors have a capacitance dependent on the separation distance. The sensor has a compressible dielectric element interposed between the conductors. The capacitance of the conductors changes in response to the separation distance changing as a result of the dielectric element compressing in response to a first object touching the sensor. The capacitance of the conductors changes in response to a second conductive object coming into proximity with at least one conductors. A controller controls the translating device as a function of the capacitance of the conductors to prevent the translating device from entrapping either of the first object or the second conductive object.

Abstract: A motor control apparatus is combined with an internal combustion engine and an electric motor to form a vehicle-propelling system. The motor is connected to a crank shaft of the engine and has both driving and power-generating functions. The motor control apparatus includes an automatic start-up/stop control device having automatic start-up control and automatic stop control sections. When the vehicle is started with a key, the automatic start-up control section uses the starter motor and always gains assistance from the electric motor in starting the vehicle. Only the automatic start-up control section controls start up of the electric motor, which prevents a noise occurring when a ring gear is engaged with a starter motor gear. This operation improves the quietness of the engine. This arrangement enhances discharge of exhaust gas.

Abstract: An electronically commutated motor is controlled by controlling the winding current of the motor. During an operational mode change of the motor, the winding current is first changed to a value in excess of the value needed to maintain a measured motor parameter at a desired level. When the desired level of the parameter is reached the current is changed to the value needed to maintain the parameter at the desired level. In addition, the communication time of the motor is shifted such that the temporal maximum of the magnetic field of the motor coincides with the position of the motor poles which results in attainment of a maximum speed altering force.

Abstract: A plant controller calculates the updated value of a control parameter for a motor controller for controlling motors for driving process machines in accordance with the change in the operational condition of a process plant so as to transmit it to the motor controller. The motor controller updates the set value of the control parameter relating to the control characteristics of the motor in accordance with the supplied updated value of the control parameter. The plant controller transmits the updated value of the control parameter to the motor controller in such a manner that the parameter code denoting the type of the control parameter and the updated value are allocated to predetermined bits of one word. The motor controller separates the received parameter code and the updated value from each other to change the setting of the control parameter, which corresponds to the parameter code, in accordance with the updated value.

Abstract: An inverter control device for controlling an induction motor that drives elevators, has two induction motor coils that are electrically separate with inverters connected to each coil, and a control device that controls these two inverters with the same current command. The preferred structure is one where one control system outputs one current command to two inverters, the inverter control device has two separate control systems that divide one current command and output each half to the respective inverter and one carrier circuit that modulates each control system at the same timing, or two separate converters are connected to the power element of the respective inverters.

Abstract: A pulse control circuit for a d.c. series motor having an armature and two oppositely-wound field windings, comprises a contactor in series with the motor, two main thyristors each connected in series with the armature and a respective one of the field windings, means for controlling the mark-to-space ratio of conduction of each thyristor, one or other of the main thyristors being brought into operation in dependence upon the desired direction of drive of the armature, means for sensing failure of commutation of the main thyristor, and means for causing opening of the contactor in response to such sensing. The control circuit includes means for firing the other main thyristor immediately commutation failure is sensed, thereby to limit the net field flux and motor torque in the period during which the contactor is opening.

Abstract: A motor control apparatus which includes a pulse generator for providing a first signal for specifying the operational condition of a motor, and a motor driver for providing a second signal for driving the motor when the first signal is at a first level and providing a second signal when the first signal is at a second level. The motor control apparatus further includes a comparator, which compares the back electromotive force of the motor with a reference level when the first signal is at the second level and providing a third signal when the back electromotive force is within a given level range prescribed by the reference level. A switch circuit closes a circuit path through which a back electromotive force current produced by the back electromotive force flows when the second and third signals are provided, thereby applying electromagnetic braking with respect to the rotation of the motor.