Abstract: An object of the present invention is to provide a generator control unit having improved voltage response in a system which is not provided with a battery in a DC output unit. In order to control the DC voltage of the DC voltage output terminal in a state where an electric load is connected to the DC voltage output terminal of a power generation unit, a PWM signal generation unit 429 generates a field voltage to be applied to a field winding terminal of the power generation unit. A feedback control unit 422 calculates a field voltage command value to be given to the PWM signal generation unit 429. Further, the feedback control unit 422 includes a PT control unit 423 which calculates a voltage deviation between a DC voltage detection value and a DC voltage command value to generate the field voltage command value through a PI operation based on the voltage deviation.

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 device for controlling and regulating the relative speed between the scroll (4) and drum (2) of a centrifugal extractor, comprising a dc or ac electric motor (10), stator (10a) of which is made integral with drum (2) and rotor (10b) of which is made integral with a gear (7) which drives scroll (4) via appropriate means (7a, 8a, 14a; 7b, 8b, 14b) of connection, there being furthermore provided means (30a, 30b) for detecting the speeds of rotation of such rotor (10b) and stator (10a) and for converting them into a representative electric signal, and means (40, 50) for comparing such electric signals designed to emit a signal (D.sub.rs) capable of operating means (60; 1060) for supplying to rotor (10b) a current capable of compensating for any deviations of the parameters of the extractor from the programmed operating conditions.

Abstract: At least two motors share a common driving circuit. The armatures of the motor are connected in parallel between the terminals of the power supply. Limiting resistors and choke diodes are included to prevent imbalances caused by different loads on the respective armatures and to maintain similar operating characteristics in the motors. The parallel motors can include either a series field winding, or shunt or permanent magnet excitation.

Abstract: Two separately-excited d-c electric motors are used to drive the wheels of a traction vehicle. The magnitude of motor field current varies as a function of the value of a variable control signal, which value is representative of any deviation of the field current magnitude from a given reference magnitude. When electric braking of the vehicle is desired, the reference magnitude is normally determined by the difference (if any) between the actual rotational speed of the slower motor and a predetermined desired speed, whereby motor field current is varied as necessary to regulate the retard speed of the vehicle. Means is provided for automatically initiating the retard speed regulation mode of operation as the vehicle accelerates and the actual rotational speed of the faster motor approaches the aforesaid desired speed.

Abstract: A speed control system for a hydraulic elevator, in which, actuating a hydraulic pump by driving an induction motor in forward direction, oil is supplied to a hydraulic cylinder for upward travel of an elevator cage, while the hydraulic pump is driven to discharge the oil from the hydraulic cylinder by driving the induction in reverse direction for downward travel of the cage. The induction motor is a single two-speed motor, which is switched to drive the hydraulic pump in one of the two speeds as desired, thus subjecting the elevator cage to two-speed control.

Abstract: A variable-speed three-phase drive is disclosed. The drive includes a switchable, undersynchronous converter cascade for driving two mechanically coupled asynchronous motors which have slip ring rotors and which can be connected separately to a three-phase network. The slip ring rotors of the two asynchronous motors are connected, respectively, with the three-phase terminals of different uncontrolled rectifiers. The latter two rectifiers, together with two inverters and two other rectifiers, are arranged in a ring circuit in such a manner that two rectifiers are always followed by an inverter. In accord with the invention, a switch is provided for connecting the three-phase terminals of the two rectifiers which are disposed on the respective cathode sides of the two inverters, and for also connecting the three-phase terminals of the two rectifiers which are disposed on the respective anode sides of the two inverters.

Abstract: An electrical propulsion control system for self-propelled traction vehicles of the type having a prime mover-driven electric generator supplying energy to traction motors and regulating means for maintaining the electrical output of the generator within desired limits, wherein the limit of generator output voltage is varied between zero and a predetermined maximum level as a function of desired vehicle speed.

Abstract: A field-controlled direct current motor is provided with a circuit responsive to armature current which is adjustable as to the amount of armature current representative signal, and the adjusted current representative signal is used to provide a selected amount of droop in the speed-load characteristic of the motor. A plurality of individually field-controlled direct current motors operating in parallel on a common load are individually adjusted as to the amount of sensed armature current to provide through field control individual selected amounts of droop in the respective speed-load characteristics.