Abstract: It is known that an output valve providing a pressure decrease in a wheel brake cylinder can be controlled by a pulse train which is variable in response to the acceleration or deceleration of the associated wheel. A disadvantage of such an arrangement is that a wheel at standstill will not be able--under certain circumstances--to accelerate again during a control cycle. Additionally, the wheel brake cylinder pressure may have been decreased to such an extent that the wheel will neither continue to decelerate, or accelerate sufficiently. According to the present invention the control behavior is improved in these critical cases by generating pulses proportional to wheel acceleration and to transmit an opening signal to the outlet valve upon cessation of the accelerating pulses. The opening signal is immediately switched off as soon as the acceleration pulses occur again.

Abstract: A brushless D-C motor of the type having a permanent magnet rotor, a plurality of individual stator windings which are disposed 90.degree. apart with respect to each other, and at least two Hall-effect galvanomagnetic transducers which are disposed 90.degree. apart with respect to each other, and within the air gap of the motor. The galvanomagnetic transducers produce control signals in response to the angular position of the rotor for controlling the conductive states of semiconductive switching devices which are each electrically disposed in series with respective individual stator windings, and a controlled current generator which controls the current flowing through the stator windings so as to conform with a sinusoidal wave shape.

Abstract: A motor drive circuit comprising a differential amplifier having inverting and non-inverting inputs and further having an output which is connected to the inputs of separate NPN and PNP, super-alpha configured amplifiers whose combined outputs are supplied to one lead of a motor. The other lead of the motor is connected through a resistor to the circuit ground. The voltage developed across this resistor is supplied to the inverting input of the differential amplifier such that the current through the motor will be equal to the input voltage supplied to the non-inverting input of the differential amplifier divided by the resistance of the resistor.

Abstract: A first pair of complementary transistors with their collectors connected to one terminal of the motor winding are alternately switched on by a rectangular wave produced by a Hall-IC responding to the magnetic field of a permanent magnet rotor, the square wave being coupled to these transistors through a resistor network and series capacitors. At the same time, another pair of complementary transistors, having their emitters connected to the other terminal of the motor winding, is directly switched by the Hall-IC, so that they operate as voltage followers to complete the path of the current pulses of the winding through the other half of a full-bridge circuit. Thus, one signal from a single sensor of rotor position operates a stator winding with full protection of the components while using a minimum of circuit elements. Such a motor makes possible ventilating fans of small axial length for use in compact apparatus.

Abstract: In response to a Hall-IC sensor exposed to the magnetic field of the rotor of a brushless d.c. motor, two interleaved sequences of pulses are generated at separate outputs with an interpulse pause of a certain length occurring between successive interleaved pulses to prevent reduction of efficiency and increase of motor noise that would result from overlapping pulses being supplied to the stator of the motor. When these pulses are utilized to switch a semiconductor full bridge circuit, through which a single winding of the stator is energized by current pulses alternating in direction, prevention of short-circuits resulting from slow turn-off of the semiconductor switches is prevented. For overcurrent protection, only half of the bridge is intermittently blocked by a current regulator when the current reaches a predetermined limiting value, this provision also reducing generation of noise and interference by the motor.

Abstract: There are provided a method of and an apparatus for controlling a pulse controlled brushless motor to immediately pull-in the motor to a predetermined rotational speed. The method has the steps of encoding rotational condition of a rotor into an electric signal, detecting the encoded signal to determine whether the rotor is in rotation or not, synchronizing a signal of a pull-in pulse rate with a clock pulse when the rotor is not in rotation and synchronizing the encoded signal with the clock pulse when the rotor is in rotation to form an input pulse train. The input pulse train is supplied to a peripheral circuit to excite the motor.

Abstract: To provide for efficient operation and recuperation of stored inductive energy in a pulse-operated motor, a preferably bifilar winding (20, 21; 20', 21') has its respective strands or filaments energized by complementary transistors (57, 58; 69, 75; 80, 81) which have reversely polarized free-wheeling diodes (59, 60; 80", 81") connected thereacross. A coupling capacity (47) is connected between the junctions of the respective transistors and the associated winding so that, upon turn-off of a transistor, as controlled by a rotor position sensor, such as a Hall generator (25), stored electromagnetic energy is coupled to flow through the free-wheeling diode of the transistor then to be connected, to be returned to a d-c source, such as a battery (34) or stored in a storage capacitor (45). The output signal from the rotor position sensor is in binary, high-low form, which can control the complementary transistors.

Abstract: A control device for a pulse motor having a plurality of polyphase stator coils, which includes a driving circuit having a plurality of power transistors arranged for sequentially energizing the stator coils, an abnormality detecting circuit arranged for comparing the input and output levels of the transistors to produce an output when the two levels are out of an inverted relationship, and a timer circuit arranged for producing a fault signal when the output of the abnormality detecting circuit is continuously produced over a predetermined period of time. The pulse motor control device may also include an alarm device and a safety device, both responsive to the output of the timer circuit to give the alarm and render the power transistors inoperative, respectively.

Abstract: An ultrasound therapy device is provided which maintains a selected constant electrical drive power to a transducer regardless of the load on said transducer by means of an analog servo feedback circuit. The device is operable in either a continuous or pulsed mode and if operated in the pulsed mode, both the pulse period and the pulse duration can be selected by the operator. Circuitry is provided to prevent the operator from selecting a pulse duration greater than the selected pulse period. Touch pad input switches may be used to input values of the operating parameters, and the chosen parameters may be displayed on digital readouts on the front panel of the device.

Abstract: A small D.C. motor has an ironless armature comprised of a winding carrier disk secured to the motor output shaft for rotation therewith and carrying an armature winding comprised of a plurality of component coils connected together in star configuration. The common or center terminal of the star-configuration interconnection of component coils is connected to one slip ring. A plurality of control circuits are provided, one for each component coil. Each control circuit connects the other terminal of the respective component coil to a further slip ring. The control circuits control the flow of current through the component coils, are light-activated and exposed to light from a lamp through the intermediary of a circle-segment aperture in a rotating light-blocking structure.

Abstract: A brush-less dc motor driving circuit is disclosed, wherein a variable constant current source is connected in series with motor windings, and motor torque proportional to motor currents is adjusted by controlling current value of said variable constant current source. Further, a supply voltage control loop is provided, so that power loss at the variable constant current source becomes minimum.

Abstract: It is known that a vehicle speed reference signal suitable for slip control can be obtained by fully releasing the braking force at one or more vehicle wheels intermittently and to obtain the true vehicle speed from the signal provided by the free-rotating wheels. However, this technique results in the stopping distance of the vehicle being longer than desired since the braking effectiveness is considerably reduced. To avoid this disadvantage, the present invention compares a speed reference signal cyclically with the instantaneous velocity signals of the wheels and to weight the comparison result dependent on whether the instantaneous velocity signal comes from a driven wheel or a non-driven wheel. The weighted comparison result provides a correcting factor for the speed reference signal.

Abstract: There is provided a control circuit for a DC brushless motor suitable for use in acoustic devices or data cassette recorders which comprises a rotor magnet rotating synchronously with the motor rotor, three or more-phase stator windings opposing the rotor magnet and spaced apart therefrom by a slight gap, winding drive circuits for supplying exciting current to the stator windings, and Hall elements for detecting angular positions of the rotor magnet and producing output voltages supplied to the winding drive circuits.

Abstract: An electric machine with electronic commutation includes two Hall elements arranged at an angular spacing about the rotor axis smaller than the phase difference .phi. required between the energizing signals in order to obtain a correct energization of the motor. The energizing circuit for the stator coils is provided with a combining circuit for linearly combining the signals obtained from the Hall elements in order to obtain signals with a phase difference equal to .phi..

Abstract: A linear motor control system for a brushless DC motor is disclosed wherein a plurality of rotor position sensors are provided together with a means for selecting a first or second group of those sensors, thus enabling alternate sets of position signals to be selected depending upon motor speed. These respective sensor signals are then processed through a filter network to provide sinusoidal motor drive signals which continuously modulate motor winding currents to provide linear speed control, thereby resulting in an appreciable decrease in acoustical noise produced by the motor.

Abstract: The invention relates to a control circuit for a brushless type DC motor of the type having a permanent magnet rotor and a pair of poles provided with two windings, the windings having a common junction which is connectable to the positive terminal of a DC voltage source. A pair of controllable switching elements are in respective series with the windings. A symmetrical square wave pulse generator responsive to the angular position of the rotor switches the switching elements on and off in a push-pull mode. The control circuit processes the square wave output and has dual outputs for driving the switching elements with the dual outputs having alternate pulses in time spaced relation to each other for driving the switching elements in underlapping relation to each other to prevent the elements from drawing current from the common junction at the same time.

Abstract: A traction vehicle propulsion system comprises a d-c motor and an excitation generator for separately exciting the motor field. Current in the field winding of the excitation generator is normally controlled by a control circuit which is arranged to prevent vehicle misdirection due to control circuit failure modes wherein normal excitation current is not supplied. The control circuit comprises means responsive to an acceleration command signal for temporarily removing the field winding from the normal control circuit and for placing it instead in a biasing circuit comprising low impedance paths to the respective terminals of a direct voltage source, thereby presetting the magnetic field of the field winding in the proper direction to prevent vehicle misdirection upon acceleration from rest.

Abstract: A multipole permanent magnet rotor is positioned on a shaft and rotatably mounted in a multiphase stator having two windings per stator phase. A distributor comprising a pattern of conducting and non-conducting material is mounted to turn with the rotor shaft. Pickup "fingers" in contact with the distributor, gate appropriate FET's of the pairs of FET's associated with each stator phase in sequence, with timing dependent on the instantaneous shaft position, to generate a rotating flux field. A voltage across the windings provides the current for flux generation, and can be supplied by a full wave rectified single phase AC source. The speed of rotation of the motor can be controlled by varying the voltage supplied.

Abstract: A drive system for a brushless dc motor to control the magnitude of the torque of a motor which has permanent magnet rotor and Hall generators. Multipliers determine the magnitude of current to each phase armature winding so as to determine the current sharing rate among the armature windings according to the rotation angle of the rotor, whereby degrading of torque uniformity due to variation of Hall generator characteristics is avoided. Each multiplier multiplies 2 signals, one being the output of the Hall generator, the other being the difference between the torque control input and the fed back signal of total armature current. Also a torque direction input is supplied to each multiplier to determine the direction of the rotational torque.

Abstract: A motor control apparatus comprises an electric reversible motor, a movable member mechanically connected to the motor, first and second electroconductive bridge members rigidly mounted on the movable member, a plurality of switches, electroconductive feelers equal in number to the number of the switches, a first circuit for supplying an electric power to the first bridge member and also to the motor to rotate the latter in one of the opposite directions when energized, and a second circuit for supplying the electric power to the second bridge member and also to the motor to rotate the latter in the other of the opposite directions when energized.