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5396161 |
Temperature compensator circuit for an induction motor
The purpose of this invention is to provide secondary resistance low temperature compensation in vector speed control at values that are close to the actual secondary time constant even at startup...
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5387856 |
Speed control arrangements for electric motors
In a speed control arrangement for an induction motor or an a.c. permanent magnet motor in which any one of a number of power frequencies may be selected for application to the motor, there is...
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5386186 |
Stator flux oriented control
In an AC drive, a method for stator flux oriented control of a waveform generator providing switching signals to an inverter supplying pulse width modulated current to a three-phase, variable...
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5382886 |
Electric waveform generating circuit for brushless motor
An electric waveform generator for a brushless motor includes a triangular wave generator including a Voltage Controlled Oscillator (VCO), a shift register, an inverting circuit, an analog switch...
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5371446 |
System for and method of driving electric automotive vehicle
A system for driving an electric automotive vehicle controls a slip frequency of a motor by feeding back to a signal control part a rotational speed detected by a motor speed sensor when the motor...
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5365158 |
Driving control apparatus for induction motor
A slip frequency type driving control apparatus includes a detector for detecting an input current and an input voltage to an induction motor, a calculating unit for calculating a rotor flux and a...
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5352965 |
Container crane driving control system
A container crane driving control system having a main hoisting mode, a travel mode, a boom hoisting mode and a trolley mode comprises a first inverter main circuit unit, a first inverter control...
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5350992 |
Motor control circuit
Power from a DC power source, such as a 12 volt RV or boat battery, is boosted and converted to provide an AC signal suitable for operating an induction motor such as a refrigerator compressor...
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5334923 |
Motor torque control method and apparatus
A method and apparatus for controlling torque by correcting slip gain error in an operating induction motor is provided. This is accomplished by measuring the amplitude and position of a flux in...
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5335307 |
Precision electric motor speed
A system and method for controlling the speed of an electric motor compares the actual speed of the motor with the desired speed of the motor. A digital comparison of the desired speed of the...
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5332956 |
Motor rotation controlling device
A motor rotation controlling device, usable for example in a video recorder, to minimize transient phenomena at an initial operation and shorten a transient response time for detecting a rotation...
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5325036 |
Elevator speed sensorless variable voltage variable frequency induction motor drive
During motor jerk-out, the real component of a stator current ReI is measured as an approximation to torque current I T , and a reference acceleration A ref is obtained as an approximation to the...
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5319295 |
Digital current regulator
A digital current regulator for controlling the operation of an inductance device such as an AC motor. A plurality of independently controllable insulated gate bipolar transistors are selectively...
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5313549 |
Procedure for filtering the speed feedback signal
A procedure is disclosed for filtering the speed feedback signal in an elevator motor drive which is provided with a speed controller and in which the speed of rotation of the motor is measured....
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5309079 |
Digital three-phase PWM signal
A clock signal is applied to an UP/DOWN counter, which counts up the clock signal from zero up to a predetermined value and then counts down from the predetermined value to zero, and thereby a...
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5304912 |
Control apparatus for induction motor
A control apparatus for an induction motor and an electric car propelling motor includes an inverter for supplying a driving current to the induction motor on the basis of a predetermined control...
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5300873 |
Motor control apparatus
A motor control apparatus for rotating a motor smoothly. A sine wave form which is an ideal wave form of a signal is stored, and the motor is driven by a signal having the ideal wave form obtained...
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5294876 |
Method and apparatus for controlling an AC induction motor by indirect measurement of the air-gap voltage
A control system for an AC induction motor, comprising a stator, a rotor, at least two stator windings and rotor windings. The control system comprises a first vector rotator for rotating control...
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5285144 |
Generation of multi-phase multiple-order harmonics of a fundamental frequency source with adjustable phase angle capability
Improved techniques and circuit arrangements are provided for generating gating signals for firing the switching devices of an inverter circuit or like power electronics generator to generate...
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5278484 |
Procedure and apparatus for braking a squirrel-cage elevator motor fed by a frequency converter in fault situations
A procedure and apparatus are provided for braking a squirrelcage elevator motor fed by a frequency convertor in fault situations using a direct current supplied from a d.c. voltage source. In the...
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5272428 |
Fuzzy logic integrated control method and apparatus to improve motor efficiency
The power efficiency of an electric motor driven load including an adjustable speed drive is improved through use of a fuzzy logic controller to provide a power efficiency signal. A fuzzy rule base...
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5270633 |
Ternary energy supply circuit with a high frequency rejection filter
An arrangement for supplying energy to a load having a low-pass frequency characteristic. A binary signal having a low-frequency component and a strong high-frequency component having a...
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5264773 |
Controller for induction motor
An error current component which becomes zero when an actual value of a primary flux coincides with a set value inducted by a product of an exciting current command and a primary self-inductance by...
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5264775 |
Pulse width modulation control apparatus and method
A controller for a multi-phase brushless DC motor which pulse width modulates the switching devices of a bridge controller, thereby energizing the phase windings of the motor in such a manner as to...
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5252905 |
Driving system for single phase A-C induction motor
By employing a single phase pulse width modulated inverter system, a-c power line voltage may be effectively converted to single phase, variable amplitude and frequency sinusoidal voltage for...
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5248926 |
Control apparatus for induction motor and electric rolling stock
A control apparatus for an electric rolling stock makes it possible to use a single associated train in a variety of transit services including an express transit service to an accommodation train...
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5241257 |
Drive system for household appliances
A drive system for a household appliance incorporates an electric motor. A control panel allows the user of the appliance to select from among various performance options which the appliance is...
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5239252 |
Method and apparatus for controlling single or multiphase A.C. power controllers
In the control of a.c. power controllers by the phase-angle control of semiconductor valves that are used to automatically control the power factor, it is necessary to determine the phase-angle...
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5231339 |
Control device for induction motor
In a slip frequency control system hitherto widely employed as a control system for an induction motor type electric rolling stock (in which a slip frequency is determined from a current deviation,...
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5227711 |
Motor controller
A motor controller accepts ac voltage at any frequency within a wide range and automatically generates an alternating polarity load-voltage having a preselected frequency, regardless of the...
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5220262 |
Method and apparatus for reducing cross-coupled movement through the structural dynamics of a computer numerically controlled machine
A method and apparatus are disclosed for reducing the cross-coupled movement in a member of a CNC machine caused by movement in another member of the machine through the structural dynamics of the...
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5206575 |
Device for controlling an AC motor
In the A.C. electric motor control device of this invention, with the object of improving response to abrupt speed adjustments and load fluctuations, and of improving stability of control under low...
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5198742 |
Method of preventing the stalling of an asynchronous machine
The invention relates to a method of preventing the stalling of an asynchronous machine controlled by a controller (6) affecting the slip and having a response time less than a rotor time constant...
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5196778 |
Control apparatus suitable for use in induction motor
A gain change-over switch according to the present invention serves to change over at least one of a current loop gain and a velocity loop gain to a value of the gain greater than that in other...
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5189357 |
Method and apparatus for improving performance of AC machines
A method and apparatus for improving the performance of polyphase AC machines. The polyphase AC machines are excited both with a fundamental frequency and with an odd harmonic of the fundamental...
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5189356 |
Voltage drive amplifier with voltage feedback
A voltage drive circuit for driving a stepping motor for a laser scanning mirror in a laser bar code reader assembly. The voltage drive circuit provides a highly damped, low q drive in which...
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5175483 |
Method and an apparatus for computing moment of inertia in a motor speed controller, and a speed control method and apparatus for a motor
In a motor speed controller for controlling an AC motor to be driven at a variable speed, a signal proportional to a load torque and a signal proportional to an output torque of the AC motor are...
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5162717 |
Loom operating apparatus and method
A loom operating apparatus and method involving the use of an inverter device interposed between loom motor and power supply. The inverter device is controlled so as to make the motor torque...
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5151017 |
Variable speed hydromassage pump control
A control for a hydromassage pump motor and pump controls the speed thereof at one of a plurality of predetermined speeds. The control includes a high voltage motor power control which is connected...
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5150030 |
Motor driving device
A motor driving device for a motor having a rotor and a plurality of excitation coils includes a detector for detecting a rotation position of the rotor, a controller for performing closed-loop...
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5146148 |
Process and a device for changing the effective speed of a polyphase asynchronous motor and a suitable motor system for the application of the process
The stator current has a variable frequency which is changed by using a predetermined frequency change rate. The resulting effective value of the stator current is compared with the current control...
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5144216 |
High speed flux feedback for tuning a universal field oriented controller capable of operating in direct and indirect field orientation modes
The direct (d) and quadrature (q) components of flux, as sensed by flux sensors or determined from voltage and current measurements in a direct field orientation scheme, are processed rapidly and...
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5130628 |
Transformer providing two multiple phase outputs out of phase with each other, and pumping system using the same
A three-phase transformer includes six windings, disposed in three pairs, all of which six windings are serially interconnected. A desired turns ratio between the two windings of each pair...
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5119007 |
Inverter control apparatus
An inverter control apparatus includes a current detector for detecting currents of two phases from among output currents of an inverter that drives an induction motor, a current coordinate...
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5107685 |
Air conditioning system having a control unit for fine adjustment of inverter input current
An air conditioning system comprises an inverter that inverts commercial power into a variable-frequency AC and supplies it to a compressor; a DC power circuit for converting the commercial power...
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5105141 |
Device to control the speed of two-phase or three-phase motors
Disclosed are a device and a method to control the speed of two-phase or three-phase A.C. motors by means of a three-phase converter. The switching-over instants of the switches of the converter...
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5075612 |
Method and device for determining the optimal excitation value which minimizes the electromagnetic losses of electric machines
A method and an electronic device for determining the optimal excitation value (stator current, magnetic flux, magnetic induction) which minimizes the electromagnetic (copper and iron) losses of DC...
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5066899 |
Control method of induction motor and device therefor
An induction motor is controlled using a control device having a current control loop by detecting a current of the induction motor, and by detecting a current error corresponding to a difference...
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5058710 |
Elevator power source device
A simplified elevator power system using an AC-DC converter, both to convert AC to DC during normal operation and to convert stored DC power to AC during power failures. A power source monitoring...
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5057760 |
Torque determination for control of an induction motor apparatus
An AC induction motor control apparatus includes the determination of the motor torque by one of the use of a torque versus dc input power lookup table for each of selected motor speeds below a...
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