Abstract: A device includes an FET 206 interposed between one end of a motor 201 and a positive electrode of a battery EB; a diode 203 for circulating an electric current so as to flow through the motor 201 after the switching means is turned off, the electric current is the same as that which has flown through the motor 201 before the switch 220 is turned off; a shunt 203a, differential amplifier 203b, and a low-pass filter 203c as means for detecting a value of an electric current flowing to the motor 210; and a controller 250 for turning on and off the switching means by the PWM control, so that the value of the electric current detected by the current detection means coincides with a target value. The controller 250 sets a very small value as the target value when the motor is rotated by inertia thereof, and supplying the electric current of the small target value to the motor 201.

Abstract: A microcomputer has a timer register 10 for storing period data of a carrier, timer registers 4A and 4B for individually storing positive phase and negative phase time width data of a control signal which is synchronized with the carrier, and an operation unit 13 for subtracting the value of the positive phase time width data of the control signal from a value of the period data. The time width data obtained as a subtraction result is supplied to the timer register 4B. The load on the CPU when the revolution of an induction motor is controlled is reduced.

Abstract: A system for cutting molten plastic material for compression molding includes a rotary-driven cutter mounted in operative association with an extruder which supplies molten plastic. The cutter is driven by a servo motor, the operation of which is coordinated with an associated rotary carousel on which cavities are successively presented to the cutter apparatus. In order to effect separation of each cut discrete quantity of plastic material from the cutting blade of the cutter apparatus, the servo motor is operated to create a period of distinct deceleration during each rotary cutting cycle, thereby effecting separation of the molten plastic from the surface of the cutting blade. The electronic controls of the apparatus further operate to permit the speed at which plastic cutting takes place to be controlled independently of the speed of the associated rotary carousel, while coordinating each cutting cycle with successive presentation of the cavities by the rotary carousel.

Abstract: A control system for a radio controlled model includes an onboard speed controller, an onboard receiver, and a separate transmitter unit having a throttle/brake trigger or other manually moveable member that an operator can move from a neutral position over a range of speed setpoint positions and a range of braking setpoint positions in order to input speed and braking setpoint information. At least one of the speed controller, the receiver, and the transmitter unit is programmed or otherwise arranged to produce a nonlinear speed controller response such that (i) the speed controller responds to an incremental increase in speed setpoint position of the moveable member near the neutral position with a smaller incremental increase in drive circuit duty ratio than when the speed controller responds to such an incremental increase in speed setpoint position near a MAXIMUM speed setpoint position (i.e.

Abstract: Method and system for controlling the operation of a motorized wheelchair where the motors have discrete predetermined speeds thus requiring little user intervention to operate and the motors may be controlled to act as generators to provide dynamic braking of the wheelchair.

Abstract: In a system including clock pulse data such as a network for sequencing music or multi-media data, a man/machine interface is provided which can be driven either by the operator or by a motor and transmission system. The man/machine interface contains encoders for producing tempo clock data which can be varied by the operator. Based on the comparison of the output signals of the encoders, the motor is accelerated or decelerated to eliminate the difference between the outputs of the encoders. The man/machine interface can be operated in the slave mode in which tempo clock data generated in the network is used to control the speed of operation of the man/machine interface or in the master mode when the man/machine interface determines the timing. The man/machine interface is preferably a foot-pedal.

Abstract: A controller for slot cars on either or both domestic and/or commercial track. A programmable pulse width modulation circuit, using at least one integrated circuit to produce an output of variable duty cycle, is provided. This modulation circuit drives transistorized power switches to deliver a DC pulsation of same duty cycle as that of the modulator. The duty cycle is programmed with the use of a simple resistive network array mounted on a small board designed to plug into the rest of the device. Full power bypassing the modulator, transistorized power switches, and filter with another alternative, regenerative braking, are additional features. This controller is revolutionary in design replacing the old wire-wound power resistor technology with modern electronic technology offering the advantages of cool efficient operation and full programmability to match any slot car motor, track, or user.

Abstract: There is provided a drive control apparatus for a motor having a drive device for controlling current supplied to an armature coil, a control device for controlling the rotation speed of a rotor, and a mode switch device for comparing a rotation speed signal and a predetermined reference voltage and generating a normal rotation mode signal or a reverse rotation mode signal. Furthermore, the drive control device has the drive device, the control device and a signal delay device. The signal delay device delays the supply of a stop signal from the control device by a predetermined time, and a reverse current is supplied to the armature coil during the delay time.

Abstract: Apparatus for use with an A.C. induction motor drive for a sewing machine to supplant a clutch-brake mechanism by supplying an A.C. induction motor drive to supply power to the motor to control its operating speed and needle position. The control embodies a programmable controller responsive to information loaded into it to derive a profile of how the sewing machine is to operate to sew workpieces, and to generate a control signal which is supplied to the motor drive to operate the motor in accordance with the profile in association with a speed command encoder responsive to a manipulative operator control to produce speed signals to speed up or slow down. The encoder senses the position of the motor and provides a position signal representative of the needle and signals the controller in a closed-loop control system.

Abstract: A sewing control system for controlling the speed of rotation of a sewing machine in which in a first embodiment, a rotation transfer ratio operation is inhibited during the time that slip occurs. According to a second embodiment, the rotation transfer operation is initiated only when the number of revolutions of the motor shaft is higher than a predetermined value. In a third embodiment, slip is prevented by not outputting a speed instruction which is not steeper than a predetermined gradient. In a fourth embodiment, when an abnormal condition is detected, the rotation transfer ratio is reduced in order to reduce the speed of the motor, thereby assuring the safety of an operator.

Abstract: A rotor speed adjustment circuit (60) reduces the rotational speed of an anode (32) of an x-ray tube (14) in a diagnostic apparatus (10). An AC current (64) from an AC current source (54) is applied to one stator winding (52). A parallel connected diode (70) and resistor (72) are connected between the current source and a second stator winding (50) to cause an effective DC magnetic braking component (66b) which reduces the rotational speed of the anode and an associated rotor (42). By selectively adjusting the resistor (72), the size of the DC magnetic braking component, hence the amount of effective drag is selectively adjustable to adjust the anode rotation speed.

Abstract: A load of an electronic sewing machine is self-diagnosed by a control system to cause a DC motor to be operated under control to drive upper and lower shafts of the sewing machine. The control system includes an evaluating device to which a voltage value applied to the DC motor and a rotating speed of the DC motor, both detected, are inputted for determining a current value supplied to the DC motor and a power loss of the DC motor. These data are supplied to a fuzzy theory applying device for estimating if the power loss of the DC motor exceeds a rated value by application of a prescribed fuzzy rule. A control command signal representing an amount of the excessive power loss is outputted from the fuzzy theory applying device to the DC motor for the control of the applied voltage. No need to directly measure the current value, and therefore no need to provide a current detecting resistor in a control circuit.

Abstract: A control arrangement for controlling the power supplied to an electric motor connected to a rotary member to drive same in rotation by way of a belt drive, to accelerate the rotary member to a given speed and to brake it in a slip-free manner provides that a signal which is proportional to the speed of rotation of the rotary member is compared to a signal which is proportional to the speed of rotation of the motor. The supply of power to the electric motor is correspondingly controlled in dependence on the result of the comparison operation.

Abstract: A conveyance (360) is provided with: 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 pulses (207a) of a pulse-width modulated driving voltage (209a); automatic limiting (233) of the rate of change in power supplied to left (26a or 232a) and right (26b) propulsion motors, whether electrically or hydraulically propelled; power-off braking that is achieved by shorting a motor winding (150a) when power pulses are not being supplied; extended life of relays (144aand 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: A variable speed eddy current electric motor includes a zero-torque regulating circuit that senses and responds to the current flowing through an eddy current motor field coil. As the magnitude of the field coil's current is changed by the eddy current motor's speed control circuit, the operating method of the zero-torque regulating circuit supplies varying amounts of current to flow through the field coil in a direction opposite to that of the current applied thereto by the speed control circuit. Thus, when the eddy current motor's speed control circuit no longer causes any current to flow through the field coil, the current supplied to the field coil by the zero-torque regulating circuit produces a magnetic filed that removes all torque from the eddy current motor's output shaft.

Abstract: An automatic braking and speed control for a device driven by an electric motor. A controller provides a pulsed output voltage having a pulse width dependent upon the load seen by the motor (16). When the drive pulses are present two diodes (52,54) and a transistor (66) serve to maintain a power transistor (56) in the off condition. When the controller is not providing drive pulses and the motor (16) is being turned by the momentum of the mechanical device or by some outside force, such as gravity, the motor (16) functions as a generator and turns on two transistors (56,67) so that two resistors (51a,51b) apply a load to the generator (16). This provides a braking action between the output pulses so that the net speed of the motor (16) and its associated mechanical device is more dependent upon the output pulses provided by the controller.

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: A digital motor control system includes a flip-flop latch for receiving motor circuit drive data from a microprocessor, a counter for counting to a predetermined value representing the total duration of a motor drive pulse, a comparator for comparing the incrementing counter value with the motor circuit drive data stored in the latch to provide a pulse width modulated signal, delay circuitry for preventing overlapping of motor brake and motor drive signals, a drive gate controlled in part by said pulse width modulated signal for applying a drive signal for motor control, and a brake gate for applying a brake signal for motor control.

Abstract: An apparatus for controlling a motor in a camera including, a motor drive unit for driving the motor in a prescribed sequence, a braking device for applying the brakes on the motor in accordance with the prescribed sequence, and a speed detecting unit for monitoring the speed of the motor and permitting initiation of the next action only after the speed of the motor, in consequence of application of the brakes by the braking device, is brought to a level incapable of obstructing the next action.

Abstract: An apparatus for an electric drive vehicle which provides linear deceleration via electrical braking. The apparatus monitors vehicle speed and adjusts the duty cycle of a chopper circuit according to look-up tables. These table correlate vehicle speed and desired deceleration rate to braking torque, thereby enabling the apparatus to maintain a preselected deceleration through the entire stopping distance and to precisely position the vehicle.

Abstract: A stepless speed change electric chain block includes a DC motor for driving a load sheave. The chain block comprises a phase control circuit having a variable resistor, a capacitor, a two-way trigger diode, and a triode AC switch for receiving alternating current from alternating power source to control it in phase, a full-wave-rectifier for receiving alternating current controlled in phase in the phase control circuit to convert it into direct current which is supplied into the DC motor, and mechanical brake means provided in a transmission between the DC motor and the load sheave for braking rotation of the load sheave in a winding-off direction. With this arrangement, as the speed setting for winding operation is effected only by the phase control circuit, so that the constitution of the block is simplified and inexpensive in comparison with the prior art. All the supplied power is effectively utilized for operating the chain block.

Abstract: In a reel-to-reel web transport (such as a magnetic tape recorder), apparatus is provided for accurately positioning a takeup reel to receive the lead end of a web. The takeup reel is rotated in web supply and takeup directions by a brushless direct current (DC) motor. A magnetic hysteresis brake is coupled to the takeup reel when the reel is rotated in a web supply direction. The rotational position of the takeup reel to receive the lead end of a web is coincident with a stable torque equilibrium position of the DC motor.

Abstract: A motor control device provided on an electric sewing machine comprising a brushless permanent-magnet motor and in combination with a magnetic pole sensor, rotational-speed and rotational-speed polarity detector for sewing machine, detectors for needle-position and needle positioning signal, and the control systems of speed and needle stagnation thereof; with the specific ways of controlling the needle stagnant position and the strength of the reverse current for braking the motor, simple structure, less power wastage and no wearable friction clutch and brake device are needed, a quick sewing machine starting, quick stabilizing of speed control and precise stagnation of the sewing needle at a preset position can be achieved.

Abstract: The present invention provides a machine driving apparatus which is composed of a brushless motor for switching the energization phase of the stator winding in accordance with the position of a rotor with a permanent magnet being provided in a rotor as a machine driving motor, compares a speed instructing signal to be generated from a speed instructing unit 32 in accordance with the displacement amount of a machine pedal 31 with a speed detecting signal detected by a speed detector 44 to control the rotational speed of a motor 42, also damps in reverse operation the motor 42 with a stop instructing signal to be generated by a position instructing unit 33 in accordance with the operation of the machine pedal 31 and a needle position detecting signal detected by a needle position detector 46 to stop the machine needle in a given position.

Abstract: A capstan motor control circuit comprises a comparing circuit for comparing an instruction voltage dependent on an instructed low-speed search mode and a rotational speed voltage dependent on a present rotational speed of a capstan motor, a circuit for detecting a rotating direction of the capstan motor and for generating a rotating direction instruction which instructs rotation in a direction opposite to a detected present rotating direction of the capstan motor, a circuit for generating a braking voltage, and a circuit responsive to an output of the comparing circuit for supplying to the capstan motor the rotating direction instruction and the braking voltage during a time period in which the rotational speed voltage is greater than the instruction voltage, and for supplying to the capstan motor the instruction voltage and a rotating direction instruction which instructs rotation in a direction identical to the present rotating direction of the capstan motor when the rotational speed voltage becomes approxi

Abstract: Automatic guided vehicles are commonly used in industrial material handling operations. Such vehicles must be accurately docked at predetermined stop locations without the guidance or assistance of human operators. The subject apparatus is used in conjunction with a vehicle having a vehicle drive circuit for controllably propelling the vehicle at a velocity responsive to a velocity command signal. At least one ground engaging wheel is equipped with a vehicle brake for controllably stopping the vehicle in response to a brake actuation signal. A position determining element produces a controlled stop signal in response to the vehicle being positioned a predetermined distance from the desired stop location, and an absolute stop signal in response to the vehicle being positioned at the desired stop location.

Abstract: The system includes a plurality of parallel-connected power field effect transistors arranged for connection in series with the traction motor with a common control circuit connected to the gate electrodes of the field effect transistors to control the on-off cycle of conduction through the field effect transistors. A plurality of parallel connected power diodes are arranged for reverse connection in parallel with the traction motor to serve as freewheeling diodes. The diodes are physically positioned apart from one another and distributed in position among the field effect transistors and each diode is positioned in a similar manner with a group of associated field effect transistors for ease of transfer of current flow between the diode and the associated field effect transistors.

Abstract: An n-phase DC motor is controlled by converting a motor speed command signal generated from a programmed CPU to a motor drive signal and using this motor drive signal to apply DC power to a selected phase of the motor, the amount of applied DC power being a function of the value of the motor speed command signal. Signals representing the position and/or speed of the motor are supplied to the CPU from which the CPU detects speed errors. The speed command signal then is modified to speed up or slow down the motor so as to reduce the detected errors.

Abstract: A control circuit for regulating the application and release of brake force in an electric brake. A pulse width modulator presents an output signal of regulatable duty cycle to power drivers connected to the electric motors of the brake. A control circuit regulates the direction of current flow through the motors to achieve either brake application or brake release. The output of the pulse width modulator is set by the position of the brake pedal or by a signal which is a function of the correlation betwen brake torque and the position of the brake pedal, whichever is larger.

Abstract: The trackside control includes a trackside d.c. power supply applied initially at low voltage (of selectable polarity, to determine the direction of vehicle motion along the track) and then increased (preferably with constant voltage-increase rate) to maximum supply voltage, and a trackside electrical braking load (preferably capable of forcing down at constant rate the voltage applied to it from the vehicle motor).The motor has series and (separately excited) shunt field windings, and on-board sensing and switching circuitry which (a) in motoring, either forward or reverse, sets full series field in flux addition to limited shunt field (b) in coasting, maintains field winding switch settings, and (c) in electrical braking, sets full shunt field and reduces the now decompounding series field.

Abstract: An electric actuator having an output member movable into and out of a force-exerting position, electric motor means operable both to move the output member to and from its force-exerting position and, when the output member is in that position, to control a spring system to generate a required output force on the output member, and means for withholding the spring system from generating a force on the output member until the output member is determined as being in its force-exerting position.

Abstract: An electric actuator which comprises an electric motor operable to a varying degree correspondingly to cause a spring to generate on an output member an output force which varies in accordance with the varying degree of operation of the electric motor.

Abstract: The present invention provides an electric actuator having an output member movable from a first variable position to a second variable position; an electric motor operable to control a spring system to exert an output force on the output member when in its second position; a device for generating an electrical signal when the output member is about to leave the second position as it returns to the first position; and a motor-control electrical circuit which recognizes the generation of the electrical signal and thereafter operates the electric motor to a pre-determined degree to move the output member a corresponding pre-determined distance back to the first position so that there is preserved a substantially constant distance between the first and second positions.

Abstract: An electric actuator having an electric motor operable to determine the output force generated on an output member by a spring system, and an adjustable stop by which can be limited the maximum value of the output force, the position of the adjustable stop being variable in accordance with variation of the required maximum value of the output force to be exerted by the output member.

Abstract: Internal combustion engine-electric drive unit for a motor vehicle is provided with a setting means for the travel speed and a signal transmitter for the actual r.p.m. of the output shaft and with a nominal-value integrator, where the running time of the nominal-value integrator is shortened in the case of a desired braking or the like in order to prevent undesirable travel movements due to a divergence of the output of the nominal-value integrator from the actual travel speed after a desired braking.

Abstract: A motor driving circuit in which the opposite ends of the motor driving coils of a video tape recorder (VTR) capstan motor are shorted by a group of switching elements when a control input voltage generated from a rotation detection/oscillator is in a predetermined range.

Abstract: In this drive control the regulating circuits for the rotational speed of a drive motor and of an eddy current brake are matched in their static and in their dynamic behavior so that a common regulator may be used for both regulating circuits. The matching is achieved by interposing a current regulation circuit for regulating the excitation current of the eddy current brake to the rotational speed regulating circuit. The output of the common regulator is supplied via a linearization member as a reference value to a regulator in the current regulation circuit during the deceleration phase. During the acceleration phase the output of the common regulator is supplied to a matching element matching the variation of the torque to the variation of the torque during the deceleration phase with respect to time. The output of the matching element is connected to the control member of the drive motor via a linearization member. By means of the linearization members the characteristics of a d.c.

Abstract: A driving and braking system having solid state switches for use with an electric motor. A first switch in series with a motor armature carries current from a power supply to the motor during the driving operation. A second switch couples a voltage from the motor armature to the first switch to render the first switch nonconductive and place the motor in a braking mode in response to a braking signal. The first switch provides armature current and couples a voltage from the motor armature to the second switch to render the second switch nonconductive and place the motor in a driving mode in response to a driving signal. The motor can be switched between the braking mode and the driving mode without bringing the motor to a stop.

Abstract: A motor control apparatus operative with a voltage source and including thyristor switch devices arranged in a bridge circuit for selectively determining forward and reverse operation of a DC series motor coupled with a vehicle, said control apparatus having provision for regenerative braking of the motor to provide current back into the voltage source.

Abstract: There is disclosed apparatus for controlling the regenerative brake operation of a transit vehicle, in relation to the polarity condition of coupled power lines having an insulator gap, by sensing that the power lines are successively supplying in relation to at least one predetermined time period, established in accordance with the vehicle travel time across that gap, a desired line voltage to the propulsion motor of the vehicle.

Abstract: For protection against commutation failures in a motor control circuit, there is provided a method and apparatus by which the charge on a commutating capacitor is made to track the armature current of a separately excited motor regardless of the operating mode of the motor. In preferred form, a commutating network is provided having a commutating capacitor, a charge reversal thyristor, and a commutating thyristor configured to cause commutation of a main, control thyristor upon sequentially gating the charge reversal thyristor and the commutating thyristor with charge of sufficient magnitude stored on the capacitor. The thyristors of the commutating network are gated according to the operating mode of the motor; thus, there is included a means, or step, for sensing the motor operating mode.

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 inherently low speed, high torque, high reliability electric motor features a simple design which is inherently amenable to simple electronic control and utilizes only elements of moderate precision. An electrical circuit distributes electric current successively to a multiplicity of circularly arrayed electromagnets to provide sequentially existing magnetic fields, which progresses around the circular array of electromagnets. The sequential fields attract successive circumferentially distributed portions of a rigid cylindrical shell or drum of ferromagnetic material. Successive portions around the periphery of the shell are pulled into engagement with the circular array of electromagnets.

Abstract: An electric vehicle control device is disclosed which includes a main circuit for supplying power from a d.c. power supply to a driving motor through a chopper, a phase shifter for controlling the conduction ratio of the chopper in such a manner that a current flowing through the driving motor is proportional to an instruction value determined by how much an accelerator pedal is trodden, a circuit for instructing a regenerative braking operation, and a changeover switch for changing over the main circuit between a power running state and a regenerative braking state. The changeover switch is changed over in the regenerative braking state when another power running state in the direction opposite to the current running direction is instructed in a predetermined time after the stop of a power running state where the chopper had a conduction ratio greater than a preset value.

Abstract: A system for automatic control of dynamic braking of an independent transport facility comprises an exciting-current regulator of traction motors provided with rotational-speed transducers whose outputs are connected to the input of a traction-motor reactive e.m.f. limiter, and a voltage transducer whose output is coupled to the first input of a traction-motor exciting-current and brake-horse-power limiter formed with three interconnected rectifying bridges, the outputs of the two bridges being connected in accord and coupled to the output of the third bridge and to one input of a comparison unit, while the inputs thereof are connected to an exciting-current transducer and to a braking intensity setter, the second input of the comparison unit being connected through a diode to the traction-motor reactive e.m.f. limiter.

Abstract: A digital servo control system for a d.c. motor to achieve stepping motor precision and a wider speed control range than either a conventional d.c. motor or a stepping motor, as may be typically utilized in an IV syringe pump. Motor position and direction sensing, as well as motor advance signals at the desired motor rate, condition motor advance and retard logic which, in turn, effects a unique counter-controlled motor drive subsystem to cause the d.c. motor to move forward, reverse, coast or slow down over a 1,000 to 1 speed control range.

Abstract: An arrangement for energy economy in a drive which includes an induction motor and a clutch-brake unit, particularly for sewing machines is provided. The windings of the induction motor are dimensioned so that the motor speed remains virtually constant in a stable speed range under normal service conditions, and in which the clutch-brake unit serves to control the drive output speed, so that the motor operates in an alternation of load phases and no-load phases. Switches are included in the current paths of the windings, which reduce the current through the windings to a prescribable degree. A modulation circuit to control the acceleration of the motor speed and its persistence in the stable speed range during load variations is associated with the switches. The modulation circuit contains a delay element, which is triggered when the mains voltage is applied, and an impulse prolongation element having a time constant dimensioned so that the motor remains in the stable speed range under all service conditions.

Abstract: The electric braking of a passenger vehicle is described, wherein the current generated by the propulsion motor in the brake mode of operation is distributed between the power supply line and a dynamic brake resistor circuit in response to the filter capacitor voltage, and with the operation of the dynamic brake resistor circuit being controlled relative to the chopper thyristor with a predetermined frequency of operation.

Abstract: A low cost power control circuit which achieves variable speed, quasi four-quadrant motor control well suited to the requirements of a direct drive clothes washing machine. For handling relatively low frequency motor direction control signals (one or two Hertz), four relatively inexpensive, low frequency thyristors are employed in a four-leg bridge circuit arrangement. For handling relatively high frequency chopper duty cycle control signals (10 kHz), a single high frequency power transistor is employed. To provide quasi four-quadrant control entirely suitable for clothes washing, a fifth thyristor and a series dissipation resistor are connected across the motor terminals and switched ON during agitation just prior to each motor reversal when motor velocity is decreasing and motor back emf exceeds applied emf. A feedback servomechanism is employed to control motor rotational velocity via chopper pulse width modulation.

Abstract: An electric actuator which comprises an electric motor operable to a varying degree correspondingly to cause a spring to generate on an output member an output force which varies in accordance with the varying degree of operation of the electric motor.