Abstract: A motor control device includes: an inverter circuit configured to convert a direct-current voltage into an alternating-current voltage, and to supply the alternating-current voltage to a plurality of motors connected in parallel; current detectors configured to detect motor currents flowing through the respective motors; a relay provided between at least one of the plurality of motors and the inverter circuit; and a controller configured to change the number of motors to be driven. When one of two or more motors under driving is stopped, the controller lowers a current instruction value to the two or more motors under driving. When a monitor current that is the motor current detected by the current detector of the motor connected to the relay is decreased, the controller switches the relay from an on state to an off state.

Abstract: A motor system includes a motor, a first electronic control unit, a second electronic control unit, a first communication line, and a second communication line. The first electronic control unit transmits first data of the control command to the second electronic control unit via the first communication line when an abnormality has not occurred in the first communication line. The second electronic control unit controls the motor based on the first data after the first data has been received from the first electronic control unit. The first electronic control unit generates second data and to transmit the second data to the second electronic control unit via the second communication line when an abnormality has occurred in the first communication line. The second electronic control unit controls the motor based on the second data after the second data has been received from the first electronic control unit.

Abstract: A fan speed control circuit is provided. The circuit includes a control chip. The control chip stores a relationship table recording a number of duty cycle intervals and a number of rotational speeds of a fan. Each duty cycle interval corresponds to one rotational speed of the fan. The control chip obtains a preset number of PWM signals outputted by a processing chip; determines the average value according to the duty cycle of the obtained preset number of PWM signals; determines which duty cycle interval the average value is in, according to the relationship table; determines the rotational speed of the fan corresponding to the determined duty cycle interval according to the relationship table; and controls the fan to rotate according to the determined rotational speed.

Abstract: An electric toothbrush is disclosed. The toothbrush includes a housing; a brush; an electric motor for driving the brush; a power supply for providing the electric power required for operation of the toothbrush; a switch mechanism for turning the drive on and off; and an electronic circuit for adjusting the effective voltage (UMot) applied to the electric motor. In operation, a voltage supplied by the power supply declines with the discharge status of the power supply from a high-voltage range to a low-voltage range. During operation of the toothbrush in the high-voltage range (H), the effective voltage (UMot) applied to the electric motor is lowered to a level at which the electric motor has reached a rotational speed corresponding essentially to the rotational speed of the electric motor in the medium-voltage range.

Abstract: When it is determined that a rotor is initially in a stationary state, a current vector is applied to a coil by a vector control method so as to rotate the rotor in a forward direction from a present position of the rotor regardless of a predetermined start position of the rotor. Therefore, a motor can be stably started with less power consumption and noise/vibration.

Abstract: An image forming apparatus includes a plurality of motors, a controller which generates control signals to control the plurality of motors and output the control signals, and a plurality of motor drivers which control corresponding motors among the plurality of motors if the enable signal among the control signal is input, and does not control the motors although the common signal is input if the enable signal is not input. Accordingly, the image forming apparatus may control a plurality of motors which is not necessary to be driven at the same time using an enable signal and thus the motors may be effectively controlled with low expense.

Abstract: A fan module, especially a fan module which may reduce a rotating speed of a fan automatically when an object with static electricity gets into the fan is provided. The fan module includes a frame, a fan, an electrostatic induction unit and a controller. The fan is disposed in the frame, and the electrostatic induction unit is disposed on the frame and adjacent to the fan. The controller is electrically coupled to the electrostatic induction unit. When an object with static electricity gets into the electrostatic induction unit, the electrostatic induction unit outputs a sensing value to the controller. The controller determines whether to reduce the rotating speed of the fan according to the sensing value.

Abstract: A method of controlling a web in, for example, a web cutter that minimizes the destructive forces that are experienced by the web. The method includes providing a motor system for driving a web handling mechanism structured to move the web, wherein the motor system includes a motor and a motor control subsystem having a digital filter (such as a PID controller or some other suitable closed loop controller), detuning the digital filter, and using the motor system having the detuned digital filter to drive the web handling mechanism.

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

Abstract: The invention relates to a vehicle seat, in particular for a motor vehicle, and equipped with a central control unit, motors, peripheral motor control devices each associated to one motor and connected to the central control unit. To allow rapid and accurate adjustments while providing versatility, the invention provides that each motor and its associated motor control device shall constitute a closed regulation loop.

Abstract: A searchlight (3) on board a vessel (1) arranged for illuminating a point (2p) and maintain said point (2p) illuminated regardless of the movements of said vessel (1).

Abstract: In response to detection of a skid of drive wheels based on an increase in angular acceleration ? of a rotating shaft of a motor, the control procedure of the invention refers to a map representing a variation in maximum torque Tmax against the angular acceleration ? and sets torque restriction of the motor to limit the torque level of the motor to the maximum torque Tmax corresponding to a peak value of the angular acceleration ?. When the torque restriction sufficiently lowers the angular acceleration ? to detect convergence of the skid, the control procedure cancels the torque restriction to a certain level of the maximum torque Tmax corresponding to a torque restoration limit ?1, which is set according to the degree of the skid. The torque restoration limit ?1 (that is, the maximum torque Tmax) is cancelled in a stepwise manner by a cancellation rate and a cancellation time corresponding to an additional accelerator depression relative to an accelerator opening at the time of detection of the skid.

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 serial fan set and rotation speed-matching curve generation method thereof are provided. The serial fan set comprises a rotation speed control module, a first fan and a second fan, in which the rotation speed control module is used to receive the power signal and produce the rotation speed driving signal corresponding to the power signal in accordance with the relations of the rotation speed-matching curve, so that the first fan and the second fan are operated at the matching rotation speed, thus producing the optimum operation efficiency and achieving the purpose of controlling the serial fan set.

Abstract: In an automotive power window system, a controller detects positions of a window glass that moves through driving operation of a motor during the closing operation of a window. The controller reduces a rotation speed of the motor when the window glass reaches a speed altering position. It calculates the amount of reduction in the rotation speed produced by the rotation speed reducing operation. Then, it corrects a rotation speed obtained during the closing operation by compensating for the amount of reduction. It determines whether an obstruction for the closing operation is present based on the corrected rotation speed. If the obstruction is detected, it controls the motor for releasing the obstruction.

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

Abstract: A clutch includes a moving gear member 65 being rotated integrally with a wheel at all times and engaged with a fixed gear member 69 when it is moved in a first direction and disengaged from the fixed gear member when it is moved in a second direction, an armature 61 pushing out the moving gear member 65 in the first direction when it is rotated relatively to the moving gear member 65, and an electromagnetic coil portion 60 that applies brake resistance to the armature 61 by attracting the armature 61 by magnetic force to restrict a concurrently-rotating-state of the armature 61 and the moving gear member 65.

Abstract: A ventilator having an abnormal operation indication device includes a power supply circuit, a central processing unit, a fan motor, and a load sensing circuit. Thus, the load sensing circuit detects the abnormal operation signals through the sensor, so that the abnormal operation indication lamp on the panel of the ventilator lights, so as to indicate that the part of the ventilator is disposed at an abnormal operation state and needs to be inspected and amended, thereby facilitating inspection and maintenance of the parts of the ventilator.

Abstract: In an automotive power window system, a controller detects positions of a window glass that moves through driving operation of a motor during the closing operation of a window. The controller reduces a rotation speed of the motor when the window glass reaches a speed altering position. It calculates the amount of reduction in the rotation speed produced by the rotation speed reducing operation. Then, it corrects a rotation speed obtained during the closing operation by compensating for the amount of reduction. It determines whether an obstruction for the closing operation is present based on the corrected rotation speed. If the obstruction is detected, it controls the motor for releasing the obstruction.

Abstract: A controller for a motor is provided. The motor includes N redundant M-phase rotor/stator combinations (where N and M are both integers greater than 1). The controller includes N driver circuits each having M outputs. Each of the M outputs of a respective one of the N driver circuits provides pulse-width modulated (PWM) current pulses to a corresponding phase winding in a respective one of the redundant M-phase rotor/stator combinations. Furthermore, the controller includes a control unit operatively coupled to the N driver circuits for providing phase spacing between the N driver circuits. As a result, current pulses provided by the N driver circuits to a same phase winding in each of the redundant M-phase rotor/stator combinations are offset in phase.

Abstract: An electric vehicle driven by electric motors is provided. The vehicle is switched between forward travel, neutral and reverse travel by a directional speed lever which allows adjustment of the vehicle speed. When the directional speed lever passes through a neutral region at a high speed during forward travel of the vehicle, the vehicle is controlled to shift to normal reverse operation after a lapse of a predetermined period of time since the rotational speed of the electric motors becomes zero, thereby to avoid application of a heavy load to drive circuits for the electric motors.

Abstract: An electric vehicle driven by a pair of left and right electric motors is provided. The vehicle includes a controller for controlling the start of the vehicle. The controller performs such control as avoiding brake drag caused by the operation of the electric motors before the elimination of the braking of a pair of left and right parking electromagnetic brakes.

Abstract: A washing machine motor drive device drives a motor using an inverter circuit, which implements a constant torque control through a change in the torque-revolution speed characteristic of the motor. This facilitates an easy control of braking torque (negative torque), thereby providing a maximized braking torque. An easy control of regenerative energy is also provided, and back electromotive force is consumed by the internal resistance of the motor. Practically described, DC power of a rectifier circuit connected to an alternating current source is converted by an inverter circuit into AC power for driving the motor for operating an agitator or a washing/spinning tub. Motor rotor position is detected by rotor position detector, motor current is detected by current detector, and a control device controls the inverter circuit for resolving the motor current into a current component corresponding to magnetic flux and a current component corresponding to torque.

Abstract: Control section determines necessary acceleration of a transporting section in accordance with an actual transporting speed, and also determines a correction coefficient corresponding to the number of rotations of an engine from among correction coefficients having a characteristic of becoming closer to a value of one as the number of rotations of the engine increases. The control section multiplies the necessary acceleration by the correction coefficient to thereby provide corrected necessary acceleration, and controls rotation of a transporting drive motor in accordance with the corrected necessary acceleration. When the amount of electric power to be generated by a power generator driven by the engine has increased, the control section controls the opening of a throttle valve.

Abstract: A method (and apparatus) includes that a duty ratio of a driving voltage output to each wiper motor be required to be set according to several conditions. That is, while each wiper blade is moved in an interval from a starting position to a predetermined first wiping position in an upward operation, the duty ratio of a wiper motor on a driver's seat side is set so that the duty ratio is larger than the duty ratio of a wiper motor on a passenger seat side. Also, while each wiper blade is moved in another interval from each upper return position to a predetermined second wiping position in a return operation, the duty ratio of the wiper motor on the passenger seat side is set so that the duty ratio is larger than the duty ratio of the wiper motor on the driver's seat side.

Abstract: The invention relates to a vehicle seat, in particular for a motor vehicle, and equipped with a central control unit, motors, peripheral motor control devices each associated to one motor and connected to the central control unit. To allow rapid and accurate adjustments while providing versatility, the invention provides that each motor and its associated motor control device shall constitute a closed regulation loop.

Abstract: A control device of an electric car in which any two of control devices fixed to the corresponding electric motors send signals to each other and send and receive control information by taking a bypass route when any one of transmission lines malfunctions is provided.

Abstract: A battery powered, joystick controlled wheelchair includes a battery by which a supply of power can be provided, a joystick by which voltages proportionate to degrees of lean from a neutral position can be produced from the supply of power, and a master power switch by which the supply of power to the joystick can be turned on and off. It is detected whether the voltages produced are forward or reverse direction voltages, and pulse width modulation, resulting in a pulse train, is provided. The pulse train is amplified to deliver driving power with a polarity consistent with a detected direction, and motors are driven by the driving power and, in turn, drive the wheelchair.

Abstract: A method for controlling a powertrain of a vehicle is described. The method determines a desired vehicle condition based on three driver actuated elements. In a preferred embodiment the first element can be pedal position, the second element can be a brake actuator or, more specifically, brake actuation duration, and the third element can be a gear selection lever. Further, the desired vehicle condition can be desired powertrain output, vehicle acceleration, or various other parameters.

Abstract: An electric vehicle driven by electric motors is provided. The vehicle is switched between forward travel, neutral and reverse travel by a directional speed lever which allows adjustment of the vehicle speed. When the directional speed lever passes through a neutral region at a high speed during forward travel of the vehicle, the vehicle is controlled to shift to normal reverse operation after a lapse of a predetermined period of time since the rotational speed of the electric motors becomes zero, thereby to avoid application of a heavy load to drive circuits for the electric motors.

Abstract: There is provided a driving force control system for a front-and-rear wheel drive vehicle, which is capable maintaining an optimum slip condition of the drive wheels even on a low-friction road surface, ensuring a proper grip of rear wheels even on a low-friction road surface or a downhill slope, even when the driver operates the steering wheel while the vehicle is performing decelerating travel on such a road, and smoothly performing the assistance of an electric motor when the vehicle is accelerated without developing a torque step, thereby ensuring stable traveling and excellent acceleration and drivability. The front-and-rear wheel drive vehicle drives the front wheels by an engine, and rear wheels by an electric motor via an electromagnetic clutch. The target driving force for driving the vehicle is calculated based on at least a vehicle speed and an accelerator pedal opening. The present traveling condition of the vehicle is determined.

Abstract: A rotational speed of an electric motor 12 is memorized at a memory unit 21 as a set rotational speed for allowing a minimum required volume of brake fluid to be discharged from the pumps in a state where the output hydraulic pressure of the master cylinder is highest, and an energizing duty ratio for the electric motor 12 which is designed so as to rotate the electric motor 12 at the set rotational speed is determined at a duty ratio determining unit 22 in response to an applied voltage detected at a voltage detecting unit 20. A motor control unit 23 controls the energizing of the electric motor 12 from a battery 18 in accordance with the energizing duty ratio determined at the duty ratio determining unit 22.

Abstract: The focus angle of a search light mounted on a helicopter or other platform is narrowed or widened by rotating a bidirectional focus control cam in a clockwise or counterclockwise direction as selected by a manually operated three-position control switch which determines the rotational direction of a DC motor driving the bidirectional focus control cam. The DC motor has first and second terminals which are selectively connected to either a DC power source or ground by a double-pole, single throw dual relay which reverses the polarity and thus the direction of rotation of the DC motor. The dual relay is connected by the same single wire interface currently in use to the manually operated control switch, which manually operated control switch is within a control box located in the helicopter.

Abstract: A motor vehicle drive system controller is adapted to automatic drive control, the engine and the transmission being among the objects of control. The power output of the motor is controlled so as to maintain either a consistent drivable mode or a consistent undrivable mode as the automatic transmission shifts gears while the vehicle is running under automatic drive control. The consistent drivable mode refers to a state where the output torque of the motor is greater than the sum of the average running resistance and the variation in the running resistance and the consistent undrivable mode refers to a state where the output torque of the motor is smaller than the difference of the average running resistance and the variation in the running resistance. The automatic drive control function is prohibited when the controller detects abnormality in the transmission.

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: The present invention relates to a procedure for selecting the mode of controlling the motor of a crane, or an equivalent lifting apparatus, when at least two alternative modes of controlling the motor are available, and at least one of the modes involves control by means of a switch having at least two positions connectable in a predetermined order, so as to produce corresponding control signals at a control input port. Each control mode uses at least one control signal common to all modes. According to the invention, the control signals applied to a control input port are monitored, the prevailing control situation is determined on the basis of the monitored signals and the mode of control is selected on the basis of which ones of the signals are active and the prevailing control situation.

Abstract: The driving apparatus for the rotation of the spindle or the work piece pallet of an electroerosive machining device comprises two electric motors which drive e.g. the spindle to a rotational movement by means of two gear boxes and a plurality of gear wheels. In order to avoid any backlash in the gear box and any clearance between the gear wheels and to compensate the elasticity of the gear transmission, the two electric motors are always operated to rotate in opposite directions and/or to yield different values of torque. Thus, the entire transmission assembly is always subjected to a certain bias force so that a precise positioning of the spindle is possible by means of simple and inexpensive driving elements.

Abstract: An electric driving device for openable members in which an openable member is opened and closed by rotation of driving shafts provided on right and left sides. The device includes a motor which rotates the driving shafts via a reduction mechanism, and switching relays which switch the rotational direction of the motor. Open and close command switches command the opening and closing of the openable member and a rotation synchronization sensor associated with the motor generates pulses synchronized with the rotation of the motor. A mechanical stopper limits the rotation of the driving shaft which is rotated via the reduction mechanism of the motor and a motor lock detecting means detects locking of the motor by detecting the pulse width generated by the rotation synchronization sensor. Also, an actuation stopping arrangement stops the actuation of an actuation device which supplies current to the motor if a signal is generated by the detection apparatus that detects locking of the motor.

Abstract: An electronic sensing and control circuit is provided which includes a sensing plate and means for charging the sensing plate to a value dependent upon the capacitance existing between the sensing plate and a remote object. The capacitance between the sensing plate and the object varies with the distance of the object relative to the sensing plate. The sensing plate is periodically discharged and charged producing a useful current proportional to the capacitance and varying with the distance between the sensing plate and the object. Two sensing plates are used to provide first and second signals. The first and second signals are subtracted to derive a lateral displacement signal and added to derive a distance signal. The lateral displacement signal and the distance signal can be used to control the forward, reverse and turning motion of a motorized wheelchair.

Abstract: A device for opening and closing a vehicle top by rotations of drive shafts rotatably provided with both right and left sides of the vehicle, comprises two individual motors which actuate the individual drive shafts through speed reduction mechanisms, switching relays which switch the direction of rotation of both said motors respectively, switching relay actuation transistors which individually actuate both the switching relays, top-open and top-close command switches which command the opening and closing of said vehicle top, a switch command determination means which ascertains whether the top-open or top-close command switches are operated, an actuation means which conducts the top opening or closing by actuation of said switching relays via said switching relay actuation transistors on the basis of a signal from the switch command determination means when the top-open or top-close command switches are operated, rotation synchronization sensors which are possessed by at least one of the two motors and gene

Abstract: The invention pertains to a control system (46) for controlling the supply of power to a motor (12) to produce plugging electrical braking and current limit control, including a circuit (60) for controlling the direction of energization of the motor (12), a circuit (88) for generating digital numbers representing command motor speeds, a circuit (14) for generating a data signal representing a plugging condition, a programmable data processor (18) for generating pulse trains in dependence on the plugging condition, and a power transistor element (40) for coupling power to the motor (12) in response to the pulse trains. By using state-of-the-art digital, integrated circuit and software technology, prior, essentially linear or discrete component technology, which is relatively unreliable, expensive and slow, need not be used.

Abstract: The invention pertains to a control circuit (10) for controlling the speed of a pair of motors (12,14), including a pair of switching elements (68,74) coupling power to the motors (12,14), a pair of controllable circuits (64,74) for driving the switching elements (68, 74), a circuit (36) for generating digital numbers representing the same command speed for each of the motors (12,14), a circuit (38) for generating digital numbers representing differential command speeds for the motors (12,14), and a data processor (56) for controlling the pair of controllable circuits (64,74) in response to the digital numbers. By utilizing digital and integrated circuit technology, prior, essentially linear, control apparatus, which are relatively unreliable, expensive and slow, need not be used.

Abstract: A control lever switch for providing steplessly adjustable control values, e.g. directional commands, for a plurality of outputs is based upon the provision of a number of electrodes in a spaced array around a control lever, these electrodes being capacitively coupled to a transmitter electrode which is carried by the control lever and which is adjustable via the control lever both radially and circumferentially of the electrode array. Preferably, four 90.degree. segment electrodes are provided, with a circular gap in the center, appropriately connected to two output channels to give, in a vehicle control system, both directional control and speed control in each channel. The electrode array and the transmitter electrode may be provided on respective opposite sides of a circuit board over which the transmitter electrode can slide easily.

Abstract: An electronic control system for controlling the operation of electromotive apparatus utilizes a capacitive sensor for sensing human touch and producing a command signal whose magnitude corresponds to the contact area of the contact. The sensor command signal is applied to an oscillator which produces a series of output width pulses having a frequency corresponding with the magnitude of the sensor command signal. A discriminator detects the trailing edge of the oscillator pulses and produces a series of fixed width pulses and an integrator produces a D.C. voltage signal corresponding to the discriminator output, which voltage signal corresponds to the area in proximity to and thereby stimulated by the human body. A comparator is employed to produce a pulse-width modulated rectangular pulse output whose duty cycle corresponds to the integrator D.C. voltage by comparing the integrator D.C. voltage with a reference triangular waveform.

Abstract: A system for controlling rotational direction switchover and for variably controlling the rotational speed of a motor comprises a circuit for switching over the rotational direction of the motor, a circuit for supplying rotation driving voltage to the motor thereby to drive it at a speed depending on the rotation driving voltage, a single voltage varying unit for varying voltage continuously, and a control signal generation circuit which receives variable voltage from the voltage varying means to generate a rotational control signal for the rotation driving voltage supplying circuit and further to generate a rotational direction switchover control signal for the switchover circuit. The voltage of the rotation control signal produced by the control signal generation circuit decreasing as the variable voltage approaches a predetermined value, reaching a minimum when the variable voltage coincides with the predetermined voltage, and increasing as the variable voltage goes beyond the predetermined value.

Abstract: There is disclosed apparatus suitable for use in conjunction with film editing tables or other devices requiring precise control over shaft rotation speed, that is, apparatus for interlocking two or more shaft rotating systems to rotate one or more slave shafts in precise speed synchronism with one remote master shaft. For each slave shaft to be controlled, there is provided a differential amplifier connected in a velocity servo loop designed to force the slave shaft to rotate in precise speed synchronism with a remote or line master shaft. The primary feedback loop comprises means for generating trains of pulses having a characteristic representative of each of the rotational speeds and for deriving from these pulse trains analog voltages which are applied to a differential amplifier to produce an error signal to be driven to zero for controlling the speed of the slave shaft.

Abstract: A remote control system for controlling the azimuth and altitude of a searchlight and also a control for selecting one of two modes of operation, either spot or flood, of the searchlight. The system includes a dual remote control of the spotlight, for use in vehicles, such as boats, where it is desired to control the direction of the spotlight and mode of operation from two separate locations. The system includes means for locking out one remote control position when the other remote control system is actuated.

Abstract: A head controlled mechanism for the proportional control of a driven devi A mechanism is provided whereby a control signal is generated proportional to the movement of the head of an operator to control the speed and direction of the driven device.

Abstract: A system for individually controlling simultaneously several electric model trains on a common track in which one of the trains is controlled in speed and direction by a voltage supply which determines the direction of the train by the polarity of its output voltage. The speed of the train is determined by the amplitude of the output voltage. Additional trains are controlled in both speed and direction by an auxiliary AC voltage supply which is connected to the supply for the first train and which superimposes pulse-waves having a Hf AC component on the voltage output of the supply for the first train. This AC component comprises pulse shaping information for controlling the velocity and direction of the additional vehicles.