Abstract: An apparatus has a first H-bridge having a first motor contact on a shared first side and a second motor contact on a second side. The apparatus also has a half H-bridge having a third motor contact on a third side, wherein the shared first side of the first H-bridge and the third side of the half H-bridge may be operated as a second H-bridge. Another apparatus has a first H-bridge having a first motor contact on a shared first side and a second motor contact on a second side. The other apparatus also has a switch coupled to a third motor contact, wherein the shared first side of the first H-bridge and the switch may be operated as a partial H-bridge. A method of operating an alternate H-bridge and a method of flexibly using an H-bridge circuit on an ASIC are also provided.

Abstract: A moving body drive control device characterized by mutually balancing a magnitude of driving force TK and a magnitude of braking force TB, both of the forces being generated by a motor, to approximate a moving speed of a moving body 100 to a target speed highly precisely without being affected by a disturbance and the like in a state where the drive control device always applies at least any force of the driving force TK and the braking force TB to the moving body 100 to always apply a driving load thereto.

Abstract: A device for supplying energy by means of a first DC voltage source e.g. in the form of a DC voltage bus, a drive system comprising several electric motors is connected to said DC voltage bus. The electric motors are comprised e.g. in a number of yarn feeding devices co-acting with a weft insertion system in a shuttleless weaving machine for producing a woven fabric having a multi-colour pattern. The electric motors operate with energy consumption function phases (start and acceleration) and with energy generating function phases (deceleration or braking). The first DC voltage source is associated with at least one second DC voltage source via a variable voltage converter.

Abstract: A load in an electrical apparatus is driven by two motors M1, M2. Switching means (R1, R2) switches the motors M1, M2 between: a series configuration, in which the motors M1, M2 are connected in series across a power supply and driven with a dc supply; and a parallel configuration in which the motors M1, M2 are connected in parallel across the power supply and driven with an ac supply. In the series configuration, a bridge rectifier BR is switched across the ac supply to provide the dc supply for the motors M1, M2 and in the parallel configuration, the rectifier BR is removed from the circuit. The arrangement can be used to drive a drum of a washing machine or a load in some other kind of appliance.

Abstract: A vibration motor obtains a FAST signal when r.p.m. of the motor is faster than reference speed, whereby an output-driving circuit is controlled by the FAST signal to omit parts of the powering periods of respective phases. The motor thus controls the r.p.m. and increases torque ripple generated from the motor. As a result, vibration magnitude increases and insufficient vibration due to downsizing of the motor can be compensated by the control system.

Abstract: A method for setting a predetermined travel of an actuator (1), in particular a piezo-electric actuator (1) for an injector of an injection system is disclosed. According to said method, a first electric state variable (Q) of the actuator (1), which determines the travel of the actuator (1), is set. Said first electric state variable (Q) is set in accordance with the temperature (TAKTOR) of the actuator (1), to avoid temperature-induced fluctuations of the actuator travel.

Abstract: A motor controller circuit for controlling an electric motor in response to motor commands from a host controller. The controller circuit includes a motor driver circuit for providing motor driver signals to the motor in response to motor driver commands. A control logic circuit is responsive to command words from the host controller for generating motor drive control signals, the controller has an associated motor identification, each command word having associated therewith a motor identification portion and a motor command portion. The control logic compares the motor identification portion of the command word to the motor identification, and converting the motor command portion into motor driver control signals if the motor identification portion corresponds to the motor identification. Multiple motors can be interfaced to a host controller, either in parallel or in a cascaded manner. Each motor has an unique address, and can interpret a command word and execute a command addressed to the motor.

Abstract: The present invention provides a circuit for operating a plurality of bi-directional motors, each motor having a pair of terminals disposed across the motor. The circuit includes a common half bridge for providing one of power and ground to one of the pair of terminals across each motor. A plurality of particular or individual half bridges, one particular half bridge for each motor, provide the other of power and ground to the other of the pair of terminals across each motor. A controller selectively controls the common half bridge and the particular half bridges to supply power in either direction across the pair of terminals of one or more of the motors. In a preferred embodiment, the controller selectively controls the common half bridge and the particular half bridges to independently pulse width modulate power in either direction across the pair of terminals of one or more of the plurality of motors.

Abstract: AC servo motor drives which allow several AC drives to be connected in parallel and allow for the connection and reconnection of AC servo motors to be accomplished primarily through a central processing unit (CPU). Thus, multiple AC servo motor drives may be ganged under the supervision of the CPU to provide a servo motor with multiple times the current available from a single drive and optionally redundancy in the drives. To provide necessary coordination, the required motor current magnitude and phase (current vector) are broadcast by an axis controller to the drives. This command current vector is broadcast over a high speed serial data bus which allows many simultaneous listeners (the AC servo motor drives). To protect against damage to each drive, each of the three current output terminals is preceded by an output filter. The output filters preceding the terminals permit phase by phase parallel connection of several drives in the service of one servo motor.

Abstract: The present invention provides a fan installation for a cooling system of a motor vehicle, comprising at least two fans which respectively have an electric fan motor arranged in a separate housing and a fan wheel which can be driven by the fan motor. The fan installation also comprises a control unit for operating the fan motors. The invention provides for an improved fan installation with a simple and cost-effective design, which is achieved by arranging the control unit in the housing of one of the fans for operating both fan motors.

Abstract: An electric vehicle accessory motor drive power supply system (40) that utilizes a single power supply design to provide efficient variable speed motor control to both brushless and brush-type DC motors (42,44). The power supply system includes at least one of each type of motor along with a first DC-DC converter (46) that provides operating power to the brushless motor (42) and a second DC-DC converter (48) that provides operating power to the brush-type motor (44). Both converters (46,48) have a power input (52) connected to the electric vehicle's high voltage bus (50) and each includes a data input (54) for receiving a speed control signal (SC) indicative of desired motor speed, as well as an output (56) for providing a motor drive signal to its associated DC motor (42,44).

Abstract: Brake control apparatus and includes an electric motor arranged to drive a wheel and a brake operable to apply a braking force to inhibit the rotation of the wheel. An input signal indicative of a desired angular velocity of the wheel is provided to the control. The current flowing through the electric motor is monitored and a monitoring signal is provided. The power to the electric motor is controlled in response to the input signal by generating a control voltage. After setting the control voltage to zero the brake applies the braking force at a braking time. The braking time may be determined according to the magnitude of the monitoring signal when the control voltage is set to zero, according to the rate of change of the monitoring signal, or according to the polarity of the monitoring signal. An electric vehicle using the brake control apparatus is also disclosed, as is a method of controlling a brake for applying a braking force to inhibit the rotation of a wheel driven by an electric motor.

Abstract: A motor controller includes: a driver stage operable to provide voltage and current to a plurality of induction motors over a single power bus; and a control unit operable to monitor the current drawn from the driver stage and cause one or more of the induction motors to operate in a regenerative mode to supply current to at least one other of the induction motors when the current drawn from the driver stage exceeds a threshold.

Abstract: The motor driving apparatus comprises a plurality of motors for displacing the position of the control object member, semiconductor switch pairs, a plurality of motor driving units for connecting the motors to the power supply and a control unit for ON/OFF controlling the semiconductor switch pairs. The motors form two sets of motors with each set being formed of two motors. One end of the motors and forming each set is connected to the common motor driving unit having the semiconductor switch pair and the other end of the motors and forming each set is connected to the motor driving units having the semiconductor switch pairs in each set. When the motors of each set are driven simultaneously, the control unit turns ON and OFF two semiconductor switch pairs and drives the motors of each set on the time division basis to provide inverse output polarities of the two semiconductor switch pairs connected to the motors of each set.

Abstract: A motor control system includes a processor having a clock output terminal for outputting clock pulses in desired cycles, a plurality of motors, and a plurality of motor drivers which are provided one for each motor and drive the corresponding motors on the basis of the clock pulses input into the motor drivers through their respective clock input terminals. The clock input terminals of the motor drivers are connected to the clock output terminal of the processor in common with each other.

Abstract: In an electrical drive system an increased electromagnetic compatibility is achieved by used of AC rotating motors having no commutator and no slip rings as driving motors, whereby a simplified structure of the drive system and of the control of the drive is achieved in that, particularly plural phased stator windings of the AC motors are pulsewise controlled by use of plural channel control whereby the rotation speed of the respective rotating magnetic field of the AC motors is controlled.

Abstract: The present invention relates to an electronically adjustable actuator for actuating a plurality of actuating elements, such as valves. A control unit is provided for generating actuating signals to cause each of the valves to move with one another in a start-stop motion in accordance with a predetermined moving pattern. The control unit would measure each potential at the outermost lowest position of the valve and at the outermost highest position of the valve. A device is provided for determining the present potential percentage value of the different valve between the maximum potential as well as the minimum potential. This different value is used to determine whether an actuating signal would be used to drive each of the actuating elements in the start-stop motion.

Abstract: At least two components that use DC power to drive at least two motors, such as DC armatures, field windings, etc., collectively referred to as DC driving devices, are connected together by switching components which can be operated to selectively connect the driving devices either in parallel or series or, in the case of more than two DC driving components, in mixed parallel and series configurations. The switching components can be solid state or electromagnetic switching components, including components that have variable resistances so as to allow continuously variable control of the series/parallel connections between the elements, and can be switched by modulation of control or trigger pulses. When the DC power driving devices are in the form of DC armatures, the series and/or parallel connection effects can also be further modulated by shunt field control of the armature currents.

Abstract: A simplified wiring system for an electronically controlled vending machine of the type capable of vending multiple products out of columns, trays or other queuing means, wherein by employing DC motors and various novel circuits, one may reduce controller complexity and assembly time. Selector button sensing and motor drives are connected in a matrix configuration. Sold-out switches are connected in series with the motors. Home switches are connected in series and only momentary continuity interruption is sensed. Separate sold-out switch outputs are eliminated. Interconnect wiring is reduced by mounting both the Home switch and Sold-out switch for each motor on a motor interface board permitting operation of up to 16 motors from a 10-wire ribbon cable.

Abstract: A pair of DC motors, each having a shunt-connected field winding, are interconnected such that current supplied to the shunt field winding of one of the motors is proportional to the armature current in the other of the two motors when the speed of the other motor is between predetermined maximum and minimum speeds.

Abstract: A servo device which simultaneously controls plural servo systems, using a digital signal processor (DSP). The servo device includes plural servo systems, plural control subjects, and plural sensors which determine control quantities of the respective control subjects. The servo device also includes a calculation processing device which finds operating amounts of the respective control subjects from the control quantities which have been detected. The calculation processing device measures the gain of each servo system, and during the gain measurement of a given servo system, drops the control band of other servo systems, or sets the other servo systems to OFF or HOLD.

Abstract: An automated drafting system particularly suitable for drafting textile strands of sliver is provided. The automated drafting system includes a synchronous drive sliver drafting roller system utilizing toothed gears in the preferred embodiment operatively connecting a pair of drafting rollers with one of the rollers being directly driven by a motor to thereby cause identical rotation of both rollers. The automated drafting system also includes a system for securing and pressuring together upper and lower sliver drafting rollers wherein the lower roller of a pair of drafting rollers is preferably maintained in a fixed but rotational position while the upper roller of the pair is pressured towards the lower roller and controllably restricted as to both horizontal and vertical movement during the drafting process.

Abstract: A film driving circuit that is capable of normal driving and reverse driving to drive-control a first motor and a second motor each rotating in only one direction. The motor driving circuit is structured so the first motor driving and the second motor driving is controlled by four switching elements composing a bridge circuit. The first motor connects to the connecting points of two of the switching elements. The second motor connects to the connecting points of the other two of the four switching elements. A CPU controls the first motor and the second motor by controlling the on-off status of the four switching elements.

Abstract: A method and apparatus for controlling a multiple motor drive arranged to drive printing cylinders of a printing machine sychronously decelerates each of the drives upon a failure or defect occurring in one or more of the components of the drive system such that the individual printing cylinders are decelerated in a manner synchronized with one another with respect to rotation angle. The apparatus includes a main control device which detects a failure in one of the drive system components and controls the drive units to decelerate the drive units to a standstill in accordance with a time function. The time function is determined by the rotation of the drive unit which contains the component that failed.

Abstract: A motor controller that incorporates all of the advantages of RS-485, yet allows the user to interface with the controller through RS-232 without a separate RS-232 to RS-485 converter. The controller includes a port for receiving RS-232 compatible signals. The RS-232 signals are converted to RS-485 compatible signals which are, in turn, converted into logic level signals suitable for the motor controller. The RS-485 signals may be shared among a number of controllers, and an RS-485 port is provided for such a purpose. RS-485 ports can be interconnected via a common bus so that a number of motors can be separately controlled from a master controller (usually a personal computer) that is connected to any available RS-232 port.

Abstract: A three state switch detection circuit converts a three state input to a two-bit binary output readable by a micro-controller or other digital logic. The circuit utilized complementary NPN and PNP transistors having coupled emitters and coupled bases connected by a resistor. The collector of the PNP transistor is connected by a resistor to ground while a complementary resistor ties the collector of the NPN transistor to V.sub.BATT. Additional circuitry preferably converts the voltage output from the collectors to a suitable voltage level readable by the micro-controller or other digital logic device.

Abstract: The invention concerns a method and an apparatus for actuating a plurality of synchronous motors which are connected to a common power supply and which are respectively used for displacing an element between two limit positions and have a connection Y1 for forward motion, a connection Y2 for reverse motion and a neutral connection G. In that case the respective connection between the connection Y1 or Y2 which is in use and the power supply is interrupted by means of a limit switch which responds when the element reaches a limit position. The connection between the connection Y2 or Y1 which is not in use and the power supply remains interrupted during non-use. A respective switch element having a control input is connected upstream of the connection Y1 for forward motion and the connection for reverse motion. The control input of the switch element is connected to a respective control circuit which includes the respective limit switch.

Abstract: Electronic control apparatus of a kind used in low voltage industrial equipment such as assemblies of motors or circuit breakers. Where an overall controller, e.g. a programmable logic controller (PLC) controls an array of (e.g.) motors (M1, M2, M3) by way of respective control units (13, 23, 33) identification or location of selected motors is usually effected by an address stored in the respective control unit. A faulty control unit entails replacement and loss of the location address which has to be reentered as a skilled operation. The invention provides a separate non-volatile memory (15, 25, 35) for the location address, this memory being physically associated with the particular motor (M1, etc.). A replacement control unit (13, 23, 33) is automatically loaded with the location address which was retained.

Abstract: An electric vehicle control system for controlling a plurality of main motors for driving an electric vehicle and an auxiliary circuit. The control system includes a first circuit breaker, and a first main power converter for receiving a DC power for converting the DC power into a first AC power to supply the first AC power to the first main motor. The control system further includes a second circuit breaker, and an auxiliary power converter for receiving the DC power for converting the DC power into a second AC power to supply the second AC power to the auxiliary circuit. The control system also includes a second main power converter for receiving the DC power for converting the DC power into a third AC power to supply the third AC power to one of the second main motor and the auxiliary circuit, respectively.

Abstract: A high pressure cleaning means is described with a preferably portable housing having a high pressure pump (6) and an electric motor drive (7) for the high pressure pump (6), the motor drive having an electric drive motor (8) with a drive shaft (9) connected to the high pressure pump (6). The motor drive (7) has at least a second electric drive motor (11) and the electric motors (8, 11, 12) of motor drive (7) are coupled to one another so as to drive the high pressure pump (6) jointly. The use of universal motors as the electric drive motors (8, 11, 12) is especially advantageous. The motor arrangement is also applicable to hand saws, water pumps, shredders, vacuums (wet/dry vacuums, leaf vacuums) and various other assemblies.

Abstract: A system for powering a multicurrent locomotive having 2N motors where N is greater than or equal to 2, the system comprising 2N pairs of voltage converters respectively associated with the 2N motors, each motor M.sub.i being powered by means of an inverter connected to the terminals of a parallel capacitor. When the locomotive is powered with AC, then each of the pairs forms a 4-quadrant converter in which the two portions are implemented by the secondary winding of a transformer whose primary winding is connected directly to the terminals of the AC power supply. When the locomotive is powered with DC, the switches serve to use the voltage converters either as voltage-lowering choppers or as voltage-raising choppers. The power supply system is designed in such a manner that in the event of a converter or an inverter failing, it suffices to isolate the failed element to conserve the functions that remain.

Abstract: Disclosed is a method of controlling an internal combustion engine driven electric vehicle in power operation of the vehicle, in which control is made so that a voltage of a DC intermediate circuit is maintained to a first constant DC voltage in a first speed range of from a zero vehicle speed to a first vehicle speed, the voltage of the DC intermediate circuit is changed in proportion to the vehicle speed in the second speed range of from the first vehicle speed to a second vehicle speed, end the voltage of the DC intermediate circuit is made to be a second constant DC voltage in the third speed range not lower than the second vehicle speed, and control is further made so that an AC output of the second power converter is made to have a variable voltage and a variable frequency in the first and second speed ranges, while the AC output of the second power converter is made to have a constant voltage and a variable frequency in the third speed range.

Abstract: The present invention resides in that two of three drivers are BTL-operated in pair to drive the motor for driving the tray and one of the two drivers and a remaining one driver are BTL-operated in pair to drive the other motors. Therefore, it is possible to construct a driver circuit for driving various drive motors within an optical disk drive device by adding only one driver to a conventional driver circuit and, thus, it becomes possible to make the drive circuit as a single chip IC.

Abstract: There is disclosed a photosensitive automatic controller for use with window coverings in particular for use with venetian blinds. The controller includes a reversible motor, a drive circuit, a photosensitive sensor, a user input, a control signal processor, a command circuit and a feedback sensor. The reversible motor is operably connected to the opening and closing device and it has a predetermined range from open to closed which corresponds to the window covering being fully opened and fully closed. The drive circuit is operably connected to the motor for generating a drive signal which drives the motor in a predetermined range from opened to closed. The photosensitive sensor generates a sensor signal. The user input generates an input signal. The control signal processor is operably connected to the photosensitive sensor and the user input and the sensor signal is combined with the input signal to produce a control signal.

Abstract: A control circuit for a cool/heat pump in which two separate motors are utilized, each with a main winding and an auxiliary winding. A single dual rated capacitor is provided in series with both auxiliary windings. A selectively operative switch, which may be in the form of a thermostat, is provided in series between one of the alternating current lines and the windings of one of the motors to selectively terminate power to that motor while maintaining power to both windings of the other motor. The switch is also used to alternately energize an electric heater unit when the motor power is terminated. Such a control circuit avoids a de-icing operation normally required with cool/heat pumps working in a heating mode, when the outdoor temperature is below freezing.

Abstract: Balanced-drive multiple motors each including an armature rotatably actuated by a field winding. Cross-coupled series excitation of the field windings is accomplished by electrically connecting the field winding of each motor in series with the armature of another motor, thereby balancing the rotational speed of all the motors when unequal loads are applied. A means for adjusting the proportionate speed of the motors is also disclosed.

Abstract: A control circuit for controlling a vehicle window closing and door locking device, comprises a first circuit having three X-OR gates and one AND gate for determining the vehicle general conditions, a second circuit having AND gates and power transistors for determining the vehicle specific conditions, for energizing the individual window motors, and for activating the door lock solenoid. The windows will be closed and the doors will be locked if three conditions are met: (1) no one is seated inside the vehicle, (2) all doors are closed, and (3) the ignition key is not in the ignition.

Abstract: An elevating system especially designed for raising and lowering battens used in stages. The elevating system preferably uses two or more winch assemblies with synchronous motors coupled together in parallel to an AC inverter to provide smooth, ramped starting and stopping of the winch assemblies as well as torque boost, speed boost, and electric braking. Each winch assembly is provided with numerous safety features such as overload and underload protection, automatic releveling of the batten, thermal overload protection and cable drum lock protection.

Abstract: An electrically actuated shifting mechanism includes a reversible rail select electric motor and a reversible in-gear electric motor. Three groups of switches are provided to effect one-at-a-time operation of the motors with a center group of switches being used to effect operation of either the rail select or the in-gear motor and to determine the direction of operation of the motor. In one embodiment of the invention, the motor control circuitry also controls the operation of a main clutch motor. Four groups of switches are used to effect operation of the in-gear, rail select and clutch motors in desired directions. Pulse width modulation is used to effect simultaneous and out-of-phase operation of the in-gear and main clutch motors.

Abstract: A drive system for a printing machine with a plurality of printing units connected to one another via a gear train into which power is fed at different points by at least two motors, includes supplying each of the motors via a respective controllable, line-commutated converter. A signal is generated by each of the converters that is limited in time between two firing pulses. A current setpoint value is transferred only within a time span in which all of the converters have activated the signal. Coverage of all of the signals which are limited in time is assured in all operating states.

Abstract: Device for controlling at least one electric servomotor with high power from a low-voltage network, in particular for motorizing a turret on a tank, characterized in that it comprises, in combination:a voltage booster converter (C),a reversible chopping amplifier (A.sub.1, A.sub.2) fed by the converter (C) and delivering the current required by the motor to be controlled (M.sub.1, M.sub.2) which is of the type able to operate as a generator, anda capacitive type electric energy accumulator (B) inserted between the converter (C) and the amplifier (A.sub.1, A.sub.2).

Abstract: There are provided servo motors and servo control units for n shafts. A setting device previously sets parameters for servo control individually for each of the n shafts and previously sets parameters for servo control for a synchronizing operation. Data which determines synchronization conditions of servo motors of respective shafts is applied, when required, by an input device independently of setting by the setting device. The data which determines the synchronization conditions includes, for example, data of combination of synchronized shafts and data of section for synchronization. A moving pattern preparation device determines servo motor shafts to be synchronously controlled on the basis of the synchronization condition determining data applied through the input device and prepares a moving pattern to a target position on the basis of the parameters for servo control set by the setting device with respect to each servo motor shaft to be synchronously controlled.

Abstract: A control circuit for a cool/heat pump in which two separate motors are utilized, each with a main winding and an auxiliary winding. A single dual rated capacitor is provided in series with the auxiliary windings and an alternating current line and a selectively operative switch, which may be in the form of a thermostat, is provided in series between one of the alternating current lines and a main winding of one of the motors to selectively terminate power to that main winding while maintaining power to both auxiliary windings and the main winding of the other motor. Such a control circuit allows a de-icing operation with the cool/heat pump working in a heating mode, without blowing cold air into the room which is to be heated.

Abstract: In a method and a circuit for the monitoring of electromotive setting elements which are connected to a bridge output stage, the actual values of the currents in the branches of the bridge are compared with the desired values which apply to the corresponding state of switching. Depending on the result of the comparison and the state of switching of the bridge output stage, an error possibly present is read from a table. It should be emphasized, in particular, in this connection that with only one bridge circuit, two motors which are connected in parallel can be completely monitored.

Abstract: A rotating display element which is provided with a display surface member having four display surfaces which are selected by rotating the display surface member, and a display unit which uses the display element. The display surface member has incorporated therein a permanent magnet type motor mechanism and is driven by the permanent magnet type motor mechanism. The rotor of the motor mechanism has first and second double-pole permanent magnet members, and its stator has first and second magnetic members having wound thereon first and second exciting windings, respecitvely. The display unit has first and second power supply means for supplying power to the first exciting winding motor mechanism and third and fourth power supply means for supplying power to the second exciting windings.

Abstract: An industrial robot control apparatus for teaching an industrial robot and operating the robot in accordance with the teaching comprises a teaching handle (9) having a teaching switch (10), and a brake release switch (11) and a sequence control circuit (1). When the operator grips the teaching handle (9), the brake release switch (11) is activated, whereby a servo amplifier (6) is brought to an emergency stop condition in response to a signal from the switch, and a dynamic brake and a mechanical brake are released.

Abstract: In a control system for a power converter for driving induction motors, the control system separately controlling an exciting current component of the primary current of the induction motors contributing to generation of a magnetic flux and a torque current component of the primary current contributing to generation of a torque, a voltage detecting device detects the output voltage of the power converter, and a correcting device responds to the voltage detecting device for determining a current correction for correcting at least one of the exciting current component and the torque current component to reduce the difference of the detected voltage from a reference value of the output voltage.

Abstract: A plurality of spindles of a textile machine are all mechanically interconnected and individually grouped, the individual groups of the spindles are driven by respective polyphase electric motors having respective feed lines all connected in parallel to the output lines of a polyphase electric power supply. Either the current or the voltage of the supply is maintained generally constant independent of load and a characteristic of the electricity in the feed lines of only one of the motors is monitored in the constant-current system or in the output lines of the supply in the constant-voltage system. An alarm, for example an optical or acoustic signal or just an indication on a display or printout, is generated when the characteristic of the electricity in any one of the monitored lines varies substantially from that of the other monitored lines.

Abstract: Operation completion detection circuitry for a vend system including a plurality of individually controllably operable motors for performing a given type of operation, comprising power leads, a vend control circuit portion operatively connected to complete a circuit across the power leads through a given motor from among the plurality of motors, a cam operated switch associated with each motor and connected in series circuit therewith, each of which switches includes a first pole and a second pole, connected in common, and a controllably movable switch contact which is normally in electrical contact with the first pole of the switch means and is responsive to operation of the motor with which such cam operated switch is associated to switchably cycle between such first and second poles during a complete operational cycle of the motor, and a detector circuit which includes a monitor portion thereof operatively connected in common circuit to all of the motors and their associated cam operated switches and in se

Abstract: An electric vehicle monitoring system in which one induction motor has a rotational speed detector but another motor does not have such a detector. Separate current detectors monitor the current delivered to each of the motors. A calculations circuit uses the rotation of the one motor and a comparison of the two currents to monitor the performance of both motors.