Abstract: Circuitry for directly providing drive power to a BLDC motor having separated coils, comprising unipolar controlled current sources for supplying current to each of the separated coils; a controller, for controlling the level and phase of the unipolar controlled current sources; a polarity switch for converting the unipolar current to a bipolar (AC) current, supplied to the separated coils. The controller is adapted to shape the current being fed to the BLDC motor by the current source via the polarity switch, to be in phase with the back EMF sensed on the separated coils, and of a magnitude that corresponds to a required torque.

Abstract: A thermal hazard protection circuit for a transportation vehicle comprises an interruptible power circuit connected between a power source and load, and a failsafe circuit operative to permanently interrupt current flow under an overcurrent condition. The interruptible power circuit comprises a Positive Temperature Coefficient (PTC) component in series with bi-stable relay configured as a SPST switch. The failsafe circuit comprises a failsafe relay energized by current in the interruptible power circuit. An input of the failsafe relay is connected to the power source, and a normally closed (NC) output (not connected to the input so long as the failsafe relay is energized) is connected to a control input of the bi-stable relay that opens the SPST switch. In an overcurrent condition, the PTC component limits current flow, switching the failsafe relay input to its NC outputs, providing a control signal to open the SPST switch, rendering the interruptible power circuit non-conductive and isolating the load.

Abstract: The magnetic pole position of a rotary electric machine is electrically derived accurately by reducing a voltage error due to a dead time while suppressing the influence on the operation efficiency of the rotary electric machine. A control device performs dead-time compensation, and performs current feedback control in a d-q-axis vector coordinate system using a magnetic pole position computed on the basis of an induced voltage produced by rotation of a rotor or on the basis of a response component to a high-frequency observation signal applied to the rotary electric machine. In the case where the rotary electric machine is controlled by deciding current commands Id*, Iq* in the d-q-axis vector coordinate system, the rotary electric machine control device controls the rotary electric machine such that the magnitude of an armature current Ia becomes equal to or more than a lower-limit current Ia_min prescribed in advance.

Abstract: An APU has a gas turbine engine and a starter generator to be selectively driven by the gas turbine engine. A sensor senses windmilling of components associated with the starter generator. A lock feature limits rotation within the starter generator when windmilling is sensed. A method of operation is also disclosed.

Abstract: Provided is an electronic timepiece, including: a step motor; a motor driver; a normal drive pulse generation circuit configured to output a normal drive pulse at a designated drive rank; a rotation detection pulse generation circuit configured to output a detection pulse; a rotation detection circuit which comprises at least a first detection mode determination circuit configured to conduct determination in a first detection mode and which is configured to detect rotation or non-rotation of a rotor; a rotation determination counter circuit configured to count a number of times that the rotation has been successively detected by the rotation detection circuit; a first detection mode determination counter circuit configured to count a number of times that a detection signal generated by the detection pulse becomes a predetermined detection pattern in the first detection mode; and a drive rank selection circuit configured to designate a drive rank of the normal drive pulse based on results of the counting condu

Abstract: A control system for an electronically commutated motor (401) can rotate smoothly to very low speeds without using a high resolution encoder and can respond to variations in load without excessive speed fluctuations. The control system can be applied to motors operating with low resolution encoders and motors operating with sensorless rotor position feedback. The electronic control system can vary the magnitude and frequency of the stator excitation applied to one or more stator phase windings, the electronic control system comprising a frequency setting section (402) and a magnitude setting section (403) characterized by the fact that the frequency setting section (402) is constrained to operate over a limited range of frequencies, the maximum frequency being a function which is closely related to the frequency associated with rotation of the rotor at the desired speed.

Abstract: A sheet transporting apparatus is provided, including a transport mechanism provided with a roller, a motor, a controller, and a measuring input unit, wherein a transport route has a curved area for inverting the sheet, and the controller is constructed such that the control on the motor is executed by a closed loop control system by using a measured value of an control output at an initial stage of the transport of a sheet from a tray, and the control on the motor is switched from the control performed by the closed loop control system to control performed by an open loop control system on condition that a preset phenomenon arises after the sheet is taken out of the tray.

Abstract: A loss-less snubber drive for a permanent magnet motor. The motor system includes a first motor phase with a primary winding and an auxiliary winding. A controllable switch is positioned between the primary winding and ground such that current passes through the primary winding to ground when the controllable switch is closed. A capacitor is configured to accumulate charge when the controllable switch is opened. The auxiliary winding is configured such that charge stored by the capacitor causes current to pass through the auxiliary winding when the controllable switch is closed.

Abstract: A rotation driving system and a method to determine the presence of a rotator on a turntable are provided. The rotation driving system includes an encoder to detect rotation information of a motor, and a controller to determine whether or not a rotator is present on a turntable and also, to adjust a gain of the motor according to moment of inertia of the rotator.

Abstract: A braking apparatus for a vehicle includes a permanent magnet synchronous motor including a rotor having a permanent magnet, and a stator capable of driving the rotor to rotate and configured to couple the rotor to each of at least a pair of wheels of the vehicle; a power accumulating portion that accumulates power to be supplied to the permanent magnet synchronous motor; a conversion control portion that converts the power of the power accumulating portion to excite the stator and control the rotation of the rotor; and an in-phase excitation control portion that applies exciting brake to the wheel by exciting the stator by supplying power in the same phase as the excitation with respect to the stator in the direction of rotation of the rotor according to the control performed by the conversion control portion, wherein the wheel is stopped by the exciting brake.

Abstract: The present invention is provided to remove dust that adhered to a cooling fan. A plurality of comparators are disposed for each of a plurality of coils, respectively, and generates a back electromotive force sensing signal denoting a comparison result by comparing a back electromotive force appearing at one end of each corresponding coil with a neutral-point voltage of the coils. A driving signal synthesis circuit generates a driving control signal used to enable the fan motor to proceed the following actions: (i) enabling the fan motor to rotate toward the opposite direction as a normal operation within a specific reverse rotation period after a driving of the fan motor is started, (ii) applying a brake to the fan motor within a braking period, and (iii) enabling the fan motor to rotate toward a direction of normal operation in a normal driving period. A driving circuit drives the fan motor.

Abstract: An electric motor drive system capture and control apparatus for energy savings has an alternating current power source electrically connected to a direct current motor. A power rectifier diode rated for the alternating current power source and the direct current motor is electrically connected in a reverse bias mode between the negative supply wire of the direct current motor and a grounded neutral conductor of the alternating current power source. A ground wire is electrically connected to the direct current motor and cross connected to a hot lag wire of the alternating current power source. The direct current motor is voltage matched to the alternating current power source. A transformer is electrically connected to the alternating current power source and the direct current motor. The system may be scaled to work with a power grid or for use in a vehicle.

Abstract: A touch control arrangement is arranged for a container having a foldable cover being folded between an opened position and a closed position via an actuation unit. The touch control arrangement includes a power source and a touch actuator electrically linked to the power source, wherein the touch actuator is located out of the storage cavity of the container body and is arranged in such a manner that when the touch actuator is activated by a presence of a touch, the actuation unit is actuated to move the foldable cover from the closed position to the opened position.

Abstract: An actuating device for displacing a control device, such as a gate valve or other control mechanism, in particular for use in oil or gas production systems, includes a motor-gear unit and a threaded spindle drive, which is operable by said motor-gear unit. The threaded spindle drive includes at least a threaded spindle and a screw nut. The threaded spindle is displaceable in an essentially axial-direction so as to displace the control device between an advance position and a retracted position. The threaded spindle drive further includes a position holding means holding the attained position of the threaded spindle. The position holding means is directly connected to a motor shaft of the motor-gear unit so as to apply a holding torque to said motor shaft.

Abstract: A braking apparatus for a vehicle includes a permanent magnet synchronous motor including a rotor having a permanent magnet, and a stator capable of driving the rotor to rotate and configured to couple the rotor to each of at least a pair of wheels of the vehicle; a power accumulating portion that accumulates power to be supplied to the permanent magnet synchronous motor; a conversion control portion that converts the poser of the power accumulating portion to excite the stator and control the rotation of the rotor; and an in-phase excitation control portion that applies exciting brake to the wheel by exciting the stator by supplying power in the same phase as the excitation with respect to the stator in the direction of rotation of the rotor according to the control performed by the conversion control portion, wherein the wheel is stopped by the exciting brake.

Abstract: A method is disclosed for slowing-down control of an asynchronous machine, wherein the value of a start energy is determined and stored while the asynchronous machine is being run up from being stationary to the operating rotation speed. The asynchronous machine is braked, in the reversing mode, with braking energy which corresponds to the start energy multiplied by a correction factor wherein the correction factor assumes a value between 0 and 1. In at least one embodiment, the asynchronous machine is braked further by DC braking after braking has been carried out in the reversing mode.

Abstract: An actuating device for displacing a control device, such as a gate valve or other control mechanism, in particular for use in oil or gas production systems, includes a motor-gear unit and a threaded spindle drive, which is operable by said motor-gear unit. The threaded spindle drive includes at least a threaded spindle and a screw nut. The threaded spindle is displaceable in an essentially axial-direction so as to displace the control device between an advance position and a retracted position. The threaded spindle drive further includes a position holding means holding the attained position of the threaded spindle. The position holding means is directly connected to a motor shaft of the motor-gear unit so as to apply a holding torque to said motor shaft.

Abstract: The method is capable of equalizing time lengths of stopping a motor at load-holding stop positions of respective phases so as to average amounts of heat generation of phase coils. The method for drive-controlling electric machinery, in which a multiphase motor is used as a driving source of an assist mechanism, is performed by a control unit including a driving circuit for driving the multiphase motor. The method is characterized in that the control unit controls to stop a rotor at a load-holding stop position, at which rotation of the rotor is stopped in a state where a motor coil is energized and the rotor is in a load-holding state, and that the load-holding stop position is angularly shifted an electric angle of 180/n (n is number of phases and an integer two or more) degrees, in a prescribed rotational direction, with respect to a previous load-holding stop position of the rotor.

Abstract: To provide a motor controlling device that reduces heat generated by an armature and switching elements when an alternating motor is activated. A motor controlling device includes: an H bridge circuit 20 that has FET1 to FET4 that connect and disconnect a high potential end HV and a low potential end GND of a direct-current power supply to and from an armature Lu; and an energization control unit for controlling the amount of energization of the armature Lu by the PWM control that involves changing the ratio, in a predetermined control cycle, between an energization control period, in which the FET1 and the FET2 are turned on and the FET3 and the FET4 are turned off, or the FET3 and the FET4 are turned on and the FET1 and the FET2 are turned off, and a non-energization control period, in which the FET1 and the FET3 are turned on and the FET2 and the FET4 are turned off, or the FET2 and the FET4 are turned on and the FET1 and the FET3 are turned off.

Abstract: A method is disclosed for slowing-down control of an asynchronous machine, wherein the value of a start energy is determined and stored while the asynchronous machine is being run up from being stationary to the operating rotation speed. The asynchronous machine is braked, in the reversing mode, with braking energy which corresponds to the start energy multiplied by a correction factor wherein the correction factor assumes a value between 0 and 1. In at least one embodiment, the asynchronous machine is braked further by DC braking after braking has been carried out in the reversing mode.

Abstract: An actuating device for displacing a control device, such as a gate valve or other control mechanism, in particular for use in oil or gas production systems, includes a motor-gear unit and a threaded spindle drive, which is operable by said motor-gear unit. The threaded spindle drive includes at least a threaded spindle and a screw nut. The threaded spindle is displaceable in an essentially axial-direction so as to displace the control device between an advance position and a retracted position. The threaded spindle drive further includes a position holding means holding the attained position of the threaded spindle. The position holding means is directly connected to a motor shaft of the motor-gear unit so as to apply a holding torque to said motor shaft.

Abstract: A braking device for an electrically driven rotor comprises a drive signal generating circuit for an electrically driven rotor, an output stage, a motor for the electrically driven rotor, driven by the output stage, and a monitor circuit for detecting interruption of an electric power supply for the motor. The output stage has a MOSFET of an upper stage side and a MOSFET of a lower side, and a diode inserted between a gate of the MOSFET of the lower stage side and the electric power supply. An electromagnetic brake is generated and applied on the electrically driven rotor when the MOSFET of the upper stage side is turned OFF and the MOSFET of the lower stage side is turned ON by a control signal from the monitor circuit, and an exciter coil of the motor is shorted when the electric power supply is interrupted.

Abstract: A car control apparatus including a wheel sensor, wheel torque calculating means for calculating wheel torque from the wheel speed, drive force detecting means for detecting drive force generated by an electric motor, car body drive force calculating means for calculating car body drive force from the above drive force and wheel torque, car body drive force fluctuating component extracting means for extracting multiple frequency band fluctuating components of the car body drive force, and drive or braking force control unit for controlling the running state of a car.

Abstract: Several embodiments of electric vehicle control and control apparatus wherein the amount of regenerative braking of the vehicle and the type of braking is determined by current conditions to provide simpler and more effective control regardless of condition of the power source for the vehicle.

Abstract: A vehicle electronic controller comprises a load such as electric motor or one or more solenoids each connected in series to a power supply; a load state detection sensor for detecting the state of the load; a required minimum drive voltage calculation microprocessor for calculating a required minimum drive voltage which is a drive voltage to be supplied to the load and which is a required lowest voltage, based on the state of the load detected by the load state detection sensor; and a power supply relay circuit arranged between the power supply and the load for transforming a power voltage supplied from the power supply into the required minimum drive voltage calculated by the required minimum drive voltage calculation microprocessor to supply the transformed voltage as the drive voltage to the load.

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

Abstract: A method for rotating a printer paper-feed roller wherein the roller is driven by a DC (direct current) motor. A feedback-control signal is applied to the motor until the roller reaches a desired rotational position. The feedback-control signal is a function of an error signal, and the error signal represents the difference between the actual rotational position and the desired rotational position of the roller. When the roller reaches the desired rotational position, the applied feedback-control signal is removed from the motor, and a direct-control biasing signal is applied to the motor to reduce or prevent rollback of the roller when the feedback-control signal is removed from the motor. In one example, the signals are PWM (pulse-width-modulated) signals.

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 rotation information detection device detects rotation information of a DC motor based on a surge component waveform superimposed on a voltage waveform between the terminals of the DC motor or a current waveform of the DC motor, a circuit is provided which supplies a current of a current value Ipwm 45% during motor forward rotation or Ipwm 55% during reverse motor rotation to the motor over the period from when the motor starts braking operation to when it stops.

Abstract: When an angular acceleration ? of a rotating shaft of a motor connected with a drive shaft exceeds a preset threshold value ?slip, which suggests the occurrence of a skid, the torque control procedure sets a maximum torque Tmax by referring to a map, which gives a smaller maximum torque Tmax with an increase in angular acceleration ?, and restricts the motor torque to the maximum torque Tmax. The maximum torque Tmax is fixed to a value corresponding to a peak value of the angular acceleration ? at the time of occurrence of a skid. The torque control procedure then integrates the angular acceleration ? to give a time integration thereof over an integration interval when the angular acceleration ? once exceeds the preset threshold value ?slip and decreases again below the preset threshold value ?slip by the motor torque restriction.

Abstract: The invention is a motor stop control device for a rotating reel type gaming machine 1 which includes a stepping motor 70 having two pairs of excitation phases as a driving source of reels 3 having a plurality of symbols drawn thereon and in which the stepping motor is stopped in accordance with an operational instruction from outside. The device includes a deceleration transmission mechanism 700 for transmitting the rotation of the stepping motor 70 to rotating shafts for rotating the reels 3 at a predetermined reduction ratio and a main CPU 40 for performing control for reducing the rotating speed of the stepping motor 70 when a stop command for the stepping motor 70 is generated according to an operational instruction from the outside and for performing stop control of the stepping motor 70 through two-phase excitation.

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

Abstract: In the driving operation of a sensorless three-phase motor to be used in a rotation at a comparatively low speed (approximately 2000 RPM or less) and to be bipolar driven, the number of rotations and a rotating position are accurately detected from an induced voltage and a reverse rotation brake is applied in an accurate phase, and furthermore, a short brake is applied at a set rotation number signal or less also in braking. Consequently, it is possible to prevent phase switching from being carried out in an erroneous timing and to prevent a rotation in a reverse direction by an inertia.

Abstract: Brake mode switching signal production means detects the number of revolutions per unit time of a rotor according to a change in a positional relationship between motor windings of a plurality of phases and the rotor so as to output first and second brake mode switching signals for selecting either a short brake mode or a reverse brake mode for braking the rotation of the rotor based on the number of revolutions. Control means outputs an energization control signal for controlling energization of the motor windings of a plurality of phases in response to the first and second brake mode switching signals. Thus, it is possible to reduce the braking noise and the stopping time.

Abstract: Disclosed is an optimized brake method for braking a motor rotating at a high speed. When the motor rotates at the high speed, the present invention reduces the rotation speed of the motor using a mechanical brake method which has a relatively high rate of energy exhaustion, and when the rotation speed of the motor reduces below a predetermined speed, the present invention stops the motor using an electrical brake method. Therefore, since the mechanical brake method is used during the high speed rotation interval, heat occurrence can be prevented, and the electrical brake method is used during the relatively low speed interval so that the motor can be stopped within a short time.

Abstract: In a roller conveyor system for carrying out zone control, a conveyed article can be stopped in an approximately constant position without varying the position where the article is stopped in a desired control zone even if the weight of the article varies. In order to syop the article in a predetermined control zone, such stop control is carried out that a motor is decelerated and stopped in a plurality of braking systems depending on the change in the pulse width of a rotational pulse signal to stop the article with high precision in a predetermined stop position.

Abstract: A motor drive apparatus is provided in an injection molding machine in order to supply electrical energy to a motor. The motor drive apparatus includes an electricity accumulation unit for accumulating electrical energy; and an electricity accumulation circuit for accumulating in the electricity accumulation unit electrical energy regenerated from the motor during a deceleration period of the motor and for supplying the electrical energy accumulated in the electricity accumulation unit to the motor during an acceleration period of the motor.

Abstract: The invention relates to a method for controlling a motor vehicle having electric drive mechanism, especially a city autobus, in which one or more wheels are driven by one electric motor and which is provided with an electric brake and a control circuit, wherein when a first defined threshold value (1) of the rotational speed (n) of the electric motor is exceeded, the drive torque (m) is cut back and is reduced down to zero when the rotational speed (n) continues to increase, and that when a second defined threshold value (3) of the rotational speed (n) which is higher than the first threshold value (1) is exceeded, the electric brake is engaged and as the rotational speed increases exerts a maximum brake torque when a limit value (4) is reached.

Abstract: A motor control method stops rotation of a motor which rotates in a forward direction by applying a brake signal for rotating the motor in a reverse direction. The motor control method detects a power supply voltage, and corrects a brake signal applying time for which the brake signal is applied to the motor depending on the detected power supply voltage.

Abstract: An energization controller for an electric motor eliminates the possibility that a motor driver may be destroyed when the electric motor rotates in the opposite direction from its driving direction.

Abstract: A method of breaking a motor includes the step of applying a pulse width modulated signal to the winding of the motor. A switching voltage is used to intermittently reverse the poles of the motor for selected time periods. The time periods are separated by pauses the duration of which is dependent upon the breaking force needed to stop the motor.

Abstract: A system is provided for controlling a DC motor which is constructed to propel a golf car. The motor is a shunt wound motor having independently excited armature and field windings. The basic input to the armature of the motor is supplied through a pulse modulated chopper circuit which varies the width of the pulse in response to the throttle of the golf car. Full control of the input to the field winding is gained by the supply of power to an H bridge circuit. Armature current is continuously sensed to provide an indication of the status and performance of the car during operation. At a predetermined level of armature current the field current is adjusted to provide a higher torque at a specific speed. When armature current indicates a predetermined overspeed condition, field current is adjusted to enhance regeneration and the resultant braking. In addition, the stopped condition is continuously monitored.

Abstract: A circuit for driving a brushless dc motor includes an active deceleration circuit for rapidly slowing the motor. A phase locked loop senses a position of the rotor for commutating from a drive state to a next drive state in a sequence of drive states at an appropriate time for maintaining torque on the rotor in the direction of rotation. Thus, the rotor "chases" the energized windings. A speed control loop controls current in the windings and, thus, motor speed. When the speed of the motor exceeds a desired speed by more than a threshold amount, rather than commutating to a next drive state in the sequence, the circuit skips a commutation. By skipping one commutation, the current drive state is maintained while the rotor continues to turn, due to its own inertia, such that the rotor "passes up" the current drive state. This results in a torque on the rotor in a direction opposite rotation.

Abstract: A system is provided for controlling a D-C motor which is constructed to propel a golf car. The motor is controlled to provide performance according to a predetermined field current map which calls for a particular performance response to specified performance events. The performance events are detected by sensing actual speed and armature current and the performance response is triggered by adjustment of the field current. A performance map correlating actual speed to various events and specifying the field current response is designed for the motor used. In addition an armature current performance map is similarly constructed correlating armature current to particular performance events.

Abstract: A series-wound motor, wherein, for braking purposes, the polarity of the armature of the motor is reversed for the opposite direction of rotation. The current supply for the motor is maintained until the armature comes substantially to a standstill and subsequently, the current supply to the motor is interrupted. The braking time is controlled in dependence upon operating parameters. For example, the braking time can be controlled by a predetermined time constant for the interruption of the current supply. To prevent running in the opposite direction, a reversal preventing device can be provided.

Abstract: An electric brake circuit (10) for bringing an alternating current (AC) motor (12) to a rapid halt. When the AC motor is turned on, a braking capacitor (C1) is charged to a preselected voltage. A shunt regulator (18) prevents the braking capacitor from overcharging by shunting charging current to ground once the braking capacitor reaches the preselected voltage. In a preferred embodiment, a limit circuit (20) turns off the charging current on the subsequent positive phase of the AC line voltage powering the electric brake. By shutting off current flow to the circuit when the preselected voltage on the capacitor is reached, power consumption and size of the circuit are minimized.

Abstract: A system is provided for controlling a DC motor which is constructed to propel a golf car. The motor is a shunt wound motor having independently excited armature and field windings. The basic input to the armature of the motor is supplied through a pulse modulated chopper circuit which varies the width of the pulse in response to the throttle of the golf car. Full control of the input to the field winding is gained by the supply of power to an H bridge circuit. Armature current is continuously sensed to provide an indication of the status and performance of the car during operation. At a predetermined level of armature current the field current is adjusted to provide a higher torque at a specific speed. When armature current indicates a predetermined overspeed condition, field current is adjusted to enhance regeneration and the resultant braking. In addition, the stopped condition is continuously monitored.

Abstract: In a circuit having an electromechanical transducer, such as a motor (22), a control switch (24) is controlled by a control circuit (26) to connect the motor to, and disconnect from, a battery (12). When control switch opens, thereby disconnecting the motor from the battery, the momentum achieved by the motor tends keep the motor turning, causing the motor to behave like a generator. A switch network (28) connects a first capacitor (30), which is initially discharged, across the motor at the same time the control switch disconnects it from the battery. The momentum of the motor, and any attached mechanical system (32), generates a transient charge which is collected by the first capacitor. When the voltage produced by the collected charge reaches a peak, the switch network disconnects the first capacitor from the motor, reorients the first capacitor, and waits to apply the voltage to the motor.

Abstract: A method and apparatus for preventing overspeed of an electrically powered golf car having a shunt wound direct current electric motor with an armature winding and a field winding serially connected to respective switching devices and to a source of on-board direct current electric power. The golf car includes a control adapted and connected to regulate the current in each of the armature and field windings for controlling speed in response to an operator's command. The golf car incorporates overspeed detection by sensing the magnitude of current in each of the armature winding and the field winding and detecting when the current in the armature winding reverses direction. The magnitude of the armature winding current upon such reversal is compared to a preselected value and an overspeed signal generated when the reverse current magnitude exceeds the preselected value.

Abstract: A method and apparatus for preventing overspeed of an electrically powered .[.golf car.]. .Iadd.vehicle .Iaddend.having a shunt wound direct current electric motor with an armature winding and a field winding serially connected to respective switching devices and to a source of on-board direct current electric power. The .[.golf car.]. .Iadd.vehicle .Iaddend.includes a control adapted and connected to regulate the current in each of the armature and field windings for controlling speed in response to an operator's command. The .[.golf car.]. .Iadd.vehicle .Iaddend.incorporates overspeed detect sensing the magnitude of current in each of the armature winding and the field winding and detecting when the current in the armature winding reverses direction. The magnitude of the armature winding current upon such reversal is compared to a preselected value and an overspeed signal generated when the reverse current magnitude exceeds the preselected value.