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| Number | Title | Issue Date |
| 7777444 | Travel-driving mechanism for self-propelled working machine In a travel-driving mechanism for a self-propelled working machine such as a self-propelled lawn mower travels by using power of an electric motor 30, the torque of a driving shaft 50, which is driven by the power of the electric motor 30 throug... | 08/17/2010 |
| 7265511 | Motor control device A speed controller includes a speed integration compensation low-pass filter, an integral control system, a proportional control system, and a multiplication device means. The speed integration compensation low-pass filter has a transfer function corresponding to a ... | 09/04/2007 |
| 7067999 | Rotation control device of working machine In a neutral range preset, there are set a zone for stopping and holding a rotating body only by a mechanical brake, a zone for holding the body only by performing position holding control, and a zone for simultaneously exerting both effects, i.e., the effect of the... | 06/27/2006 |
| 6995539 | Device and a method for estimating the speed of a slip ring asynchronous machine The invention relates to a device and a method for estimating the speed of a slip ring asynchronous machine. The asynchronous machine includes a stator having a stator winding, arranged to be fed with three-phase voltage and current in order to generate a varying ma... | 02/07/2006 |
| 6933699 | Motor drive circuit and method with frequency setting and correcting functions A motor drive circuit and method with frequency setting and correcting functions. The drive circuit includes a speed control device, which simultaneously receives a sense signal and a rotation frequency signal. A pulse width modulation signal capable of modulating a... | 08/23/2005 |
| 6844701 | Overmodulation systems and methods for induction motor control Systems and methods for controlling an induction motor including detecting a field weakening operation state of the motor, wherein the field weakening operation state is detected when a flux current, Id, in the motor is reduced to a predetermined fraction... | 01/18/2005 |
| 6710573 | Method of controlling pulsed AC power PWM AC power is supplied to an induction motor or other AC load. The frequency and magnitude of the waveforms is controlled by detecting the peak voltage or width of the reverse EMF pulses at the commencement of the power waveform applied to the load, and then adjus... | 03/23/2004 |
| 6693405 | Electrical steering system An electrical steering system for a vehicle includes an electrically supplied steering motor arrangement which is connected with an inverter arrangement, whose output voltage is influenced by a computer arrangement, and a sensor arrangement. To reduce the... | 02/17/2004 |
| 6452358 | Electronic apparatus and control method for electronic apparatus In an electronic apparatus which includes a power generator and a storage device for storing electric energy obtained thereby, it is detected whether a motor driven by the stored electric energy is rotating by comparing the rotation detecting voltage, whi... | 09/17/2002 |
| 6339309 | Method and apparatus for switching an AC motor between two power supplies A method and apparatus for switching an AC motor between two power supplies such as supply mains and a variable frequency AC motor drive. In a transfer procedure, the motor drive is coupled to the motor to power the motor. When the supply main is connecte... | 01/15/2002 |
| 6163137 | Rotary induction machine having control of secondary winding impedance A rotary induction machine in which operating characteristics of the machine are controlled by adding impedance elements to the rotor windings in which the impedance elements are stationary and connected to the rotor windings by a rotary transformer.... | 12/19/2000 |
| 5986438 | Rotary induction machine having control of secondary winding impedance A rotary induction machine having wound primary and secondary windings with resistive means connected in series with secondary windings and inductive reactive means connected across said resistive means, with the inductive reactance means and resistive me... | 11/16/1999 |
| 5652495 | Controller for permanent magnet synchronous motor A controller for a permanent magnet synchronous motor which includes a D-axis current command section and a Q-axis current command section. The D-axis current command section increases the command value of the D-axis current so as to set a judged value to... | 07/29/1997 |
| 5587642 | Fan motor brown-out control algorithm An air conditioner having a fan motor brown-out control algorithm for increasing the air conditioner fan speed upon sensing a brown-out under-voltage condition is provided. The air conditioner has a power supply connected to an AC line voltage, a fan moto... | 12/24/1996 |
| 5457374 | Motor controller for operating an inverter in current-controlled and voltage-controlled modes A motor controller for brushless motors operates an inverter in a current-controlled mode for low motor speeds and in a voltage-controlled mode for high motor speeds. By switching from the current-controlled mode to the voltage-controlled mode at higher s... | 10/10/1995 |
| 5410234 | Motor drive control apparatus A motor drive control apparatus having an electrical power amplifier for supplying an electrical power to a motor, and a current control loop and speed control loop for controlling the drive of the motor, which includes a current feedforward component cal... | 04/25/1995 |
| 5013990 | Energy conserving electric motor power control method and apparatus An energy conserving device which reduces excess level of alternating current power fed to RUN windings of an a.c. electric induction motor whenever the motor is less than fully loaded. A voltage dropping reactor coupled between an a.c. power source and t... | 05/07/1991 |
| 4742288 | Control system for AC motor/generator of secondary AC excitation type A control system for controlling the load of an AC motor/generator of secondary AC excitation type connected to a power system in parallel to at least a synchronous machine. The AC motor/generator has the secondary excitation winding thereof controlled in... | 05/03/1988 |
| 4388579 | Control system for a wound-rotor motor A load switching circuit for switching two or more transformer taps under load carrying conditions includes first and second parallel connected bridge rectifier circuits which control the selective connection of a direct current load to taps of a transfor... | 06/14/1983 |
| 4385267 | Controlled rotor rectifier arrangement for a slip-recovery drive SCR devices replace the usual diodes of the rectifier bridge section of a wound-rotor slip-recovery system motor drive. By controlling the retardation angle of the SCR devices while controlling the line bridge for acceleration from zero speed to normal sp... | 05/24/1983 |
| 4206395 | Harmonic eliminating apparatus An AC motor has polyphase stator windings connected to an AC bus and has polyphase rotor windings connected directly or through impedances to capacitors. The capacitances of the capacitors are selected so as to be such that the AC motor exhibits a small i... | 06/03/1980 |
| 4140951 | Mining machine A mining machine includes drive unit means for driving a haulage winch and a cutting tool of the machine, the drive unit means comprising a multi-phase induction motor with a wound rotor. In order to control the motor speed, the motor is provided with a c... | 02/20/1979 |
| 4065704 | Static speed control circuit for polyphase induction motors A modified three-phase bridge circuit, incorporating resistors and thyristors connected in specific configuration in one leg of each phase circuit and diodes in a second leg, is adapted for connection to the motor rotor. A speed control signal, modulated ... | 12/27/1977 |
