Abstract: A system for controlling multiple inverter-driven loads includes a controller that is configured to be coupled with an inverter that receives direct current and converts the direct current into an alternating current in order to supply the alternating current to plural loads that are connected to the inverter by plural respective contactors. The controller also is configured to control operations of the inverter and of the contactors in order to individually control which of the loads remain connected to and powered by the inverter and which of the loads are disconnected from the inverter.

Abstract: A fan control system includes a first fan, a second fan that is adjacent to the first fan, a first motor that is configured to rotate the first fan, a second motor that is configured to rotate the second fan, and a control unit. The control unit is configured to control the rotational speeds of the first motor and the second motor, and to decrease the rotational speeds of both the first motor and the second motor when the rotational speed of the first motor must be decreased.

Abstract: A heating system and a method of controlling the heating system are provided. When a heating unit and a switch are turned on and off repeatedly by the predetermined number of times or more, only some of heaters of the heating unit are turned on, thereby increasing service life of the heating unit and the switch.

Abstract: A control device includes a control module controlling a polarity switching unit connected electrically to a motor unit of a food processor to provide a first current path for an input power signal through the motor unit when the control module is operated in a processing mode, and further controlling the polarity switching unit to provide a second current path for the input power signal through the motor unit when the control module is operated in a braking mode. A power control unit is connected electrically to the motor unit and the control module, and controls the power control unit such that the power control unit reduces an amount of the input power signal that flows through the second current path during a braking period when the control module is operated in the braking mode.

Abstract: A battery-powered vehicle for transporting a mined payload or supplies over the roadways existing in or around an underground mine, includes variable voltage, variable frequency drivers that convert DC voltage from a battery into an AC voltage for driving AC induction motors of a front wheel drive system of the vehicle, and a further variable frequency driver that converts DC voltage from the battery into an AC voltage for driving an AC pump motor for supplying hydraulic fluid to hydraulically operated components of the vehicle. A controller controls the operation of the variable voltage variable frequency drivers in response to commands supplied to the controller by an operator of the vehicle.

Abstract: A driving control device for an actuator comprises a driving device to drive an actuator having an electric motor (30) and a driving control device (50) to control the rotation of the electric motor (30) by controlling the driving device. The driving control device includes an H bridge circuit constructed by four switching semiconductor elements (Tr1 to Tr4), and rotates the electric motor in normal and reverse directions by turning on and turning off the switching semiconductor elements (Tr1 to Tr4). The driving control device (50) conducts to activate and to stop the electric motor (30) by applying a PWM signal to the switching semiconductor elements (Tr3 and Tr4) constructing the lower arm of the H bridge circuit (51).

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 motor control method and apparatus for stopping an object moved by a motor accurately at a predefined target position, shortening the time period required in stop control, in which the motor is driven at a first (high) speed up to a distance from the target position adequate for stop control and then is sequentially braked to a predetermined speed lower than the first speed, driven at a second (low) speed up to a distance from the target position equal to the stopping distance, and braked to a stop. The method and apparatus are used in a time recorder. An impact printing apparatus is also disclosed with printing pin actuation timing correction dependent upon scanning speed or platen shape, striking duration timing dependent upon scanning rate, or printing pin actuation timing dependent upon stored shift amounts.

Abstract: A power steering system and induction motor load compensation algorithm or processing method for use in a vehicle. The power steering system comprises a power supply, a power steering motor, a steering subsystem, and a power steering controller coupled to the power supply. The controller processes a frequency command input corresponding to the power steering frequency requested by the steering subsystem and data contained in one or more software lookup tables to adjust the output frequency produced by the power supply to control the speed of the power steering, motor. The lookup tables are generated empirically and characterize the output power of the power supply at different system pressures over a range of motor speeds. The software lookup tables provide a power band that implements a power limiting state machine.

Abstract: A power-assisted wheelchair (1) having an electric motor (32), a potentiometer (27) as means for detecting human power applied to wheels (2), and a controller (31) as means for controlling the electric motor (32) according to the detected human power so as to set the time-attenuation rate of the assist power to be greater as the human power is smaller, and to be smaller as the human power is greater. Therefore, the coasting amount of the wheelchair (1) for small indoor movements for example is restricted to a small value. As a result, small indoor movements with a small turning radius are made possible, a sufficient coasting amount is secured for an outdoor running. Therefore, along with the possibility of a comfortable running on a level road, a steep uphill running is made easy, and the physical effort of the rider is alleviated.

Abstract: A controller for detecting abnormal operating conditions of a continuous motion machine such as a packaging machine. The acceleration and velocity of motors for the various axes of the machine are examined by the controller and rapid deceleration or a more gradual deceleration to a lower velocity relative to a machine velocity are employed for stopping the machine when overloads in the form of jams or mechanical faults occur in moving parts of the machine. By using this system, machine overloads can be detected much earlier than by using conventional techniques, and as a result, damage resulting from overloads and nuisance tripping can be eliminated or greatly reduced.

Abstract: A power drive device is disclosed that includes a motor, a control device coupled to the motor, and a rotatable reference axle member rotatably interlocked with the rotation of the motor. A first detection member detects a first phase and a third phase of rotation of the reference axle member wherein the first phase corresponds to a rotation starting position of the reference axle member and the third phase corresponds to a near completion position of the reference axle member. The device also includes a second detection member that detects a second phase and a fourth phase of rotation of the reference axle member, wherein the fourth phase of rotation corresponds to a rotation completion position of the reference axle member. The control device drives the motor in accordance with the detected phases of the first and second detection members, and in particular, can control the velocity of the motor and the timing of the operation of the motor in relation to a second motor.

Abstract: In a drive arrangement of a motor vehicle in which the wheels of the motor vehicle are driven by separate electric motors and the electric motors are powered via a d.c. voltage intermediate circuit by a generator arrangement driven by an internal combustion engine, the speed of the internal combustion engine and individual wheels is sensed by speed sensing circuits which respond to pulse signals of commutator circuits of the generator arrangement and electric motors. The commutator circuits generate the pulse signals depending on position transmitters which are arranged at the generator arrangement and at the electric motors. In this way, the speeds can be sensed with great accuracy exclusively on the basis of already existing components of the drive arrangement. In particular, the speed sensing means cooperate with an antilock braking system (ABS) and a drive slip regulating system (ASR).

Abstract: A heat engine operates an alternator that supplies electrical power to an electric continuously variable transmission for driving at least one ac motor through a differential to multiple wheels or to multiple independent ac wheel motors in an automobile, bus or truck. A heat engine control operates in a closed-loop power mode and decouples heat engine speed from motor speed, allowing the heat engine to produce required power at an operating speed and throttle position, or fuel injector duty cycle, that maximizes fuel economy and minimizes engine emissions. An energy storage unit (e.g., a battery, flywheel, ultracapacitor, superconducting magnetic energy storage device, or combination thereof) provides electrical energy to the electric drive system during vehicle accelerations and further reduces peak power demands on the heat engine. Advantageously, energy is recovered during vehicle deceleration and braking; and the recovered energy is used to recharge the energy storage unit.

Abstract: The present invention relates to a motor control device using an inverter or inverters, in particular, it relates to a motor control device suitable for the prevention of inertial rotation of a motor or motors or for the maintenance of synchronized operation of a plurality of motors in a service-interruption time; a DC side voltage is compared with a target voltage and a correction signal relating to the deviation voltage is added to a speed instruction for the inverter; thereby in a service-interruption time a motor can be continuously and smoothly decelerated keeping the DC side voltage of an inverter at a target voltage value. By utilizing a motor control device according to the present invention for a spinning machine etc., unevenness in thread winding or thread cut in a service interruption time can be prevented.

Abstract: A propulsion system for using a pair of electric induction motors to power a pair of vehicle drive wheels. The motors are driven by pulses of electric current from a common dc bus. The inductance of stator windings cause electric current to power the motors during the time between pulses so power from the dc bus is low. When a vehicle is making a tight turn, an inside motor provides an electric current to the dc bus to supply additional power to an outside motor. Speed and steering signals operate the electric motors and control speed of an engine and an alternator which supply power to the dc bus.

Abstract: An original drum and a recording drum are driven independently by individual synchronous motors. Encoders output respective rotation timing pulses (P.sub.a, P.sub.b) at every rotation of the recording drum and the original drum. If an interval separating the timing pulses (P.sub.a, P.sub.b) becomes smaller than a prescribed value, a scanning line deviation control circuit generates a motor control signal (T.sub.b) which interrupts the delivery of electrical power to the faster moving motor for a limited period such as to restore a correct relationship between the timing pulses.

Abstract: A conveyance (10) is provided with: automatic limiting (223) of the rate of change in power supplied to left (26a or 232a) and right propulsion motors, whether electrically or hydraulically propelled; dynamic braking of electric propulsion motors (26a and 26b) that is achieved by shorting a motor winding (150a) during a portion (233a) of an interval (217a) between power pulses (207a) of a pulse-width-modulated driving voltage (209a); power-off braking that is achieved by shorting a motor winding (150a) when no power pulses are being supplied; extended life of relays (144a & 148a) that is achieved by preventing current flow to the motors during opening and closing of the relay contacts (154a and 156a); and a solid-state switching device (168a and 170a) that is controlled by a signal in a single conductor (200a) and that provides an effective delay (219a and 221a) in switching between two circuits (152a and 160a).

Abstract: In a tape drive system, a dynamic brake control circuit provides dynamic braking for slowing and stopping an associated tape reel and motor system in the event of a power failure. Upon sensing a power failure, the electrical energy stored in a capacitor supplies electrical energy to enable the control circuit, which in turn supplies a controlled conductive path for the flow of a dynamic braking current due to the back electromotive force signal generated by the motor, to effect the controlled dynamic braking of the drive motor to a stop.

Abstract: In the drive for a textile working machine, for the synchronized yet independently operable drive of at least two shafts, brake-clutch units associated with each shaft are provided, which are driven by a common electric motor. To achieve a regulation and control having good dynamic properties and fast response, provision is made for the brake-clutch units to be controlled such that the rotatory speed of the driven shaft of the first brake-clutch unit is given as a required value, and the rotatory speed of the second brake-clutch unit is synchronized through the rotatory speed of the driven shaft of the first brake-clutch unit, systems being provided for establishing the rotatory speed ratio.

Abstract: Two separately-excited d-c electric motors are used to drive the wheels of a traction vehicle. The magnitude of motor field current varies as a function of the value of a variable control signal, which value is representative of any deviation of the field current magnitude from a given reference magnitude. When electric braking of the vehicle is desired, the reference magnitude is normally determined by the difference (if any) between the actual rotational speed of the slower motor and a predetermined desired speed, whereby motor field current is varied as necessary to regulate the retard speed of the vehicle. Means is provided for automatically initiating the retard speed regulation mode of operation as the vehicle accelerates and the actual rotational speed of the faster motor approaches the aforesaid desired speed.

Abstract: A dynamic braking system is provided for electrically driven wheelchairs to slow the wheelchairs to a stop without needing to use a mechanical brake. A primary switch arrangement is provided for connecting resistors across the right and left wheelchair motors automatically when the switch control is in its off position, either because of purposely positioning the control by the patient or as a consequence of power failure. In addition, a secondary switching system is automatically actuated in response to the primary switching system being moved to its off position to cross connect or short circuit the terminals of the right and left motors to each other only after a given period of time to provide a secondary braking action to the motors and bring the wheelchair to a complete rest.

Abstract: A power fail circuit provides protection for tape such as used in the tape transport apparatus of a video recorder in the event of a failure of the external power supply. The tape transport apparatus includes as a feature the provision of an electrical error signal used to govern drive motors to maintain substantially constant tape tension when the system is operating normally. After power failure occurs, the power fail circuit continues to respond to the error signal by coupling current from the drive motors to provide dynamic braking. Further, current taken from the drive motors selectively is coupled to an energy storage device operatively associated with the system power supply, to provide augmenting energy from the kinetic energy of the motors for continued control of the power fail circuit as the drive motors are caused to decelerate under control to stop.

Abstract: A cam controller for determining the operation of an electric motor is coupled with a stepping motor to provide predetermined positional movements of the cam controller in response to a desired electric motor operation control signal and in accordance with a programmed microprocessor determined comparison of the actual electric motor current with a requested current related to the desired operation control signal.

Abstract: A dynamic braking system for a D.C. traction motor which is driven from an asymmetric bridge rectifier having freewheel diodes to permit circulation of motor generated current. The system employs field reversal to ensure a generated (braking) current direction the same as for motoring and this facility permits injection current braking by phasing up the supply bridges when the motor is braking with full excitation. The brake resistance is in two parts one of which forms an uncontrolled arm of the bridge, this part of the resistance being shunted by a thyristor. Part way through an injection braking process the supply bridge is phased down, the resistance bridge arm shorted out and the supply bridge phased up again. Lower losses and greater braking efficiency result.

Abstract: When a plurality of shunt motors connected in parallel are used for driving an electric railcar, the differences in the characteristics of the motors introduced during the manufacturing thereof causes the armature currents to vary greatly even when they are running at the same speed. To control the field current by means a single device, therefore, the armature currents must be corrected by armature choppers. In order to fully recover the kinetic energy possessed by the electric railcar, the present invention automatically corrects for the difference in the characteristics of the shunt motors so that the required braking force is uniformly borne by each of the shunt motors.

Abstract: A phase locked loop control system, in particular for use for synchronizing the operation of a carriage drive motor and a main drive motor in a photocopier, uses a digital frequency- and phase-comparator and relies on the output pulses, used to power the slaved motor, being shaped so that each positive-going d.c. drive pulse is followed by a negative-going d.c. braking pulse of smaller amplitude, to provide positive registration of the slaved motor with the pulsed driving signal.

Abstract: An electric control is disclosed for an electrically powered vehicle having independently controlled left and right drive motors and associated drive wheels to propel and steer the vehicle. The electrical control includes left and right closed loop control circuits for respectively accelerating either or both of the drive wheels whenever a speed command or error signal associated with such drive wheel exceeds a first determined value. Dynamic braking is provided by connecting in parallel electrical relationship an associated brake resistor across one or both of the motors whenever the speed command signal associated with such motor does not exceed a second predetermined value.

Abstract: An electric group drive having synchronous motors which are fed from a static operating converter has a second converter for use in varying the relative angle position of the motors. Provision is made for using the second converter as a start-up and braking converter. A phase shifter and memory-oriented control logic are used to control the processes.

Abstract: A solid-state motor control apparatus operative with a plurality of series motors to determine the selection of a power mode of operation and a brake mode of operation, and including a plurality of current sensors to establish the current flow in the motor armatures and in the motor fields.

Abstract: An apparatus is provided for use with a motor drive for cancelling the electromagnetic reaction energies developed by a pair of drive motors upon rapid starting or sudden stopping, the latter occurring upon the application of dynamic braking to said motor drive. The apparatus comprises a pair of motors each provided with rotors preferably having moments of inertia which are substantially equal. The output shafts of the motors are operatively connected so as to rotate in opposing directions.

Abstract: A motor control system for a pair of motors which drive respective wheels of a vehicle which is steered by controlling the relative speed of the motors includes switch means, and a pair of resistors which are connected in a series circuit including the motors, when no current is being supplied to the motors in order to provide electrical braking of the motors.

Abstract: A microfilm reader has a film transport mechanism driven by separate forward and reverse motors. During operation, the driven one of the motors receives full AC power for driving it at high speed. During low speed operation, the driven motor receives partial power during half-cycles of one polarity, but only minimal power during half-cycles of opposite polarity. The undriven motor is pulled by its associated reel as the film is unwound therefrom. A large capacitor, which is part of a series circuit including both the forward and reverse motors, charges while either motor runs. When a driven motor is stopped, the capacitor is discharged into both of the motors to provide a unipolar field which produces a braking torque. Thus, the capacitor discharge not only stops the driven motor quickly and efficiently, but also stops the undriven motor to maintain film tension.

Abstract: An interlock circuit is provided for tape and film machines which, when the high speed forward or reverse motors are in operation, prevents the main power from being turned off even though the operator might actuate the power switch. Instead of the power going off when the main power switch is operated during high speed operation, the machine continues to operate until the operator takes his hand off the fast forward or reverse drive switch, and then the brake is energized to stop the motion of the film or tape. When the brake cycle is complete, the power is then automatically turned off.

Abstract: Static switching device for two machines making it possible to effect antkid control during drive operation and the controlling of the braking torque during brake operation. It comprises two circuits in parallel on the direct current source, a first circuit comprising, in the following order, a first chopper, a first smoothing inductance, an inductance of the first machine, a first distributing thyristor and an armature of the first machine and a second circuit comprising, in the following order, an armature of the second machine, a second distributing thyristor, a second smoothing inductance and an inductance of the second machine, the two circuits being connected together by two connections arranged on either side of the said first and second distributing thyristors, each of the connections bearing a distributing thyristor. Applications -- Controlling of electric motors used for the propulsion of vehicles.