Did You Know...
...that the inventor of the electric motor was a blacksmith named Thomas Davenport? Described as "a brilliantly unsuccessful inventor", Davenport invented the first rotary electric motor. In 1836 he headed out -- on foot -- from his Vermont home to file a patent application at the Patent Office in Washington, D.C. By the time he got there, he had squandered away his money and couldn't afford the $30 filing fee so he turned around and went home. When he later mailed in his application with money he'd raised, the Patent office was destroyed in a fire. He did finally get credit for his invention on Feb. 5, 1837.
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| Number | Title | Issue Date |
| 8138701 | Method for determining the position of a rotor of an electric motor without sensors Disclosed is a method for detecting the current position of a rotor, in particular the angle of rotation of the rotor, an electromotor and a method for detecting the speed and/or the angle of rotation of an electromotor. The speed of the electromotor is hereby impli... | 03/20/2012 |
| 7999501 | Motor controller A motor controller (2) for an axial-gap motor (1), which has a rotor (3), two stators (4, 5) disposed on both sides of the rotor (3) in the axial direction, and armature windings (6, 7) wrapped around the stators (4, 5 | 08/16/2011 |
| 7915852 | Universal adaptive torque control for PM motors for field-weakening region operation The invention includes a motor controller and method for controlling a permanent magnet motor. In accordance with one aspect of the present technique, a permanent magnet motor is controlled by, among other things, receiving a torque command, determining a normalized... | 03/29/2011 |
| 7479755 | Drive circuit for a synchronous electric motor The drive circuit (10) includes a processing and control circuit (14) comprising a protection circuit (16), designed to generate at its output a logical inhibiting signal (C) starting from every zero crossing of the motor supply volts (V), the i... | 01/20/2009 |
| 7443130 | Motor driving control device In a motor driving control device, a high-frequency alternating voltage or rotation voltage (having a frequency of ωh) is applied to a motor so that magnetic saturation occurs in the motor, thereby extracting, from a γ-axis current, a high-frequency sec... | 10/28/2008 |
| 7439696 | Rotating electric machine and manufacturing method thereof A control device of a rotating electric machine to which an inverter is integrally assembled is downsized, and manufacturing costs are reduced. An inverter for controlling outputs from the rotating electric machine is integrated with a rotating electric machine, and... | 10/21/2008 |
| 7391175 | Device and method for driving electric actuator A smart actuator that includes a driving device and an electric actuator such as a DC motor includes a driving current detecting circuit, a driving circuit connected to the electric actuator, a control circuit that controls the driving circuit according to current d... | 06/24/2008 |
| 7378814 | Method for controlling a wound rotor synchronous motor A method for the control of a wound rotor synchronous motor comprises measuring a plurality of electromagnetic entities indicative of the operation of the motor, generating voltage on a stator of the motor to obtain a stator current, further generating a further vol... | 05/27/2008 |
| 7375482 | Driving device of motor An object is to provide a driving device capable of smoothly shifting from a starting state to a sensor-less vector control, in a case where the device drives a motor by the sensor-less vector control, and the device includes a voltage detecting circuit which detect... | 05/20/2008 |
| 7372232 | Apparatus for drive control, power conversion, and start-up control in a PMBDCM or two-phase SRM drive system A power converter for a switched reluctance motor (SRM) or a permanent magnet brushless direct current (do) motor (PMBDCM) may include a front-end boost partial circuit for connecting with a first phase winding of the motor to form a front-end boost circuit and a ba... | 05/13/2008 |
| 7358698 | Field-winding type of synchronous machine A field-winding type of synchronous machine comprises a stator with an armature winding wound phase by phase, a rotor having a rotor core with a field winding wound, and a circuit enabling an armature current to pass the armature winding, the armature current corres... | 04/15/2008 |
| 7352145 | Voltage-sensitive oscillator frequency for rotor position detection scheme A system and method is provided for improved monitoring and controlling of mechanically commutated DC motors. The system and method include DC motors, pulse-count driver circuitry for driving the motors, motor position sensing circuitry, and motor control circuitry.... | 04/01/2008 |
| 7348684 | Drive unit A drive unit is provided including a synchronous machine, a pulse counter unit for detecting a rotor position during the running operation of the synchronous machine, and a control unit. The control unit is constructed such that, with the start of the operation of t... | 03/25/2008 |
| 7323839 | Direct current motor controlling method A direct current motor controlling method includes a mean for transforming a duty signal to computed value by a microprocessor unit. The microprocessor unit computes the computed value and then produces a target value by executing a dichotomy method, a rotation meth... | 01/29/2008 |
| 7245105 | Single-phase induction motor and method for reducing noise in the same A single-phase induction motor and a method for reducing noise in the same, which can eliminate unbalance between magnetomotive forces of main and auxiliary windings in a stator of the motor, thereby implementing a low noise, low vibration motor, and can also achiev... | 07/17/2007 |
| 7211985 | Training device On a training device, in particular for developing human muscles, having a torque-generating unit which comprises an electric motor and a reduction gearing, and whose output interacts with at least one training element offered to the exercising person, an electric m... | 05/01/2007 |
| 7211984 | Start-up and restart of interior permanent magnet machines A method of starting a permanent magnet machine. A machine stator voltage in a stationary reference frame is sensed. An initial speed of a rotor of the machine is estimated based on the sensed voltage, and state variables of control algorithms are initialized based ... | 05/01/2007 |
| 7190130 | Electric motor pole position sensing method, pole position sensing apparatus, and electric motor control apparatus using the same It is an object of the invention to provide a method which can detect a magnetic pole position easily and surely by using high-frequency currents such as harmonics of an inverter output and carrier frequency components. The invention provides a method of detecting a... | 03/13/2007 |
| 7161324 | Device for estimating pole position of synchronous motor An influence resulting from double saliency of an electric motor, i.e., an influence of a deviation of the axis of an alternating current due to a rotor magnetic pole position θ on the estimation of a magnetic pole position, is eliminated, and, in particular, the m... | 01/09/2007 |
| 7145311 | Vector control device of winding field type synchronous machine A vector control device of a winding field type synchronous machine with which even when voltage changes caused by resistance voltage falls and inductance fluctuations due to armature current occur the armature voltage is controlled exactly to a desired command valu... | 12/05/2006 |
| 7076340 | Method of controlling speed of synchronous motor, and method of identifying constant of synchronous motor In sensorless vector control performed through use of a rotation speed of a synchronous motor 6 and the position of a rotor, a positive current is caused to flow to a γ axis on the assumption that a “d” axis serving as a true magnetic axis is out of phase with ... | 07/11/2006 |
| 7058291 | Brushless DC motor A system and method for reducing the cost of producing a brushless DC motor (58) is presented. The brushless DC motor (58) provides higher power density and efficiency with an increased tool run time. The brushless DC motor (58) includes a rotor... | 06/06/2006 |
| 7023165 | Stepping motor control apparatus A stepping motor control apparatus in accordance with the present invention comprises: a current detection unit that detects phase currents flowing into a stepping motor; an equivalent model-of-motor arithmetic unit that includes a coefficient multiplication block w... | 04/04/2006 |
| 7019484 | Stepping motor driver A stepping motor driver according to the present invention includes a torque component current calculating means for calculating a torque component current from phase currents and a rotor rotation angle, an absolute value converting means for obtaining an absolute v... | 03/28/2006 |
| 6984959 | Wound field synchronous machine control device A synchronous machine control device includes a flux command generator, a magnetic flux estimator, a divider, a flux controller and γ- and δ-axis armature current controllers. The flux command generator produces a flux command from the synchronous machine turning ... | 01/10/2006 |
| 6979975 | Rotation state detecting apparatus of a synchronous machine In a conventional rotation state detecting apparatus of a synchronous machine, since short-circuiting must be carried out twice or more when a rotation speed is detected, there have been problems in that it takes a time to detect a rotation state, and it takes a tim... | 12/27/2005 |
| 6979979 | Gas turbine engine starter-generator exciter starting system and method including a capacitance circuit element A rotating electrical machine, such as an aircraft starter-generator, that includes an exciter that has its stator windings supplied with electrical power from a power supply. One or more switches are electrically coupled between the exciter stator winding and the p... | 12/27/2005 |
| 6969962 | DC motor drive circuit A DC motor drive circuit includes a position detector for producing an output signal that corresponds to a rotational position of the rotor, a current controller for controlling current supply to the winding in accordance with the output signal of the position detec... | 11/29/2005 |
| 6956341 | Motor driving control device Two inverters (INV1, INV2) supply phase currents to three-phase coils (Y1, Y2). Although two phase currents must conventionally be measured and four current sensors are thus required, according to the present invention, the number of phas... | 10/18/2005 |
| 6933688 | Brushless direct current monophase motor drive circuit A brushless direct current motor drive circuit having a serially connected motor coil energizing circuit, a serially connected feedback circuit, a pre-drive circuit, a position sensor, and a duty ratio controller. This circuit can decrease the heat generation from t... | 08/23/2005 |
| 6911798 | Rotation angle detecting apparatus for synchronous rotary electric machine A rotation angle detecting apparatus for a synchronous rotary electric machine includes an incremental encoder. The incremental encoder generates an index pulse each time electric power is supplied to said plurality of phase-coils and an auxiliary index pulse each t... | 06/28/2005 |
| 6909263 | Gas turbine engine starter-generator exciter starting system and method including a capacitance circuit element A rotating electrical machine, such as an aircraft starter-generator, that includes an exciter that has its stator windings supplied with electrical power from a power supply. One or more switches are electrically coupled between the exciter stator winding and the p... | 06/21/2005 |
| 6897591 | Sensorless switched reluctance electric machine with segmented stator A sensorless switched reluctance machine includes a stator with a plurality of circumferentially-spaced stator segment assemblies that include salient stator poles and inter-polar stator slots. Each of the stator segment assemblies includes a stack of stator plates ... | 05/24/2005 |
| 6885166 | Regulating system having a simple hardware unit for regulating an electric machine optionally in PWM operation or block operation A method and a device for regulating a polyphase machine, in particular a synchronous machine, in which a direct-axis voltage and a quadrature-axis voltage are determined as manipulated variables of the regulating system, and also including a pulse-width-modulation ... | 04/26/2005 |
| 6885163 | Method for starting a brushless d.c. motor A process to start a brushless direct current motor with a multiphase stator winding is disclosed, in which, during rotor standstill, a plurality of current impulses is intruded on the stator winding, the current rise time until a current threshold is reached is mea... | 04/26/2005 |
| 6856114 | System for measuring motor rotor position The present invention relates to a method for the sensorless electric measurement of the position of a rotor of a permanently excited synchronous machine that is fed by a converter, by means of measuring signals which are sent to an evaluation device that calculates... | 02/15/2005 |
| 6853163 | Rotor position detection of a switched reluctance drive A switched reluctance drive is controlled without using a physical rotor position detector. The control method estimates the standing flux-linkage associated with the phase and uses this estimate to improve its estimate of rotor position. The method works robustly r... | 02/08/2005 |
| 6850027 | Stepping motor driver The stepping motor driver comprises an inverter for feeding stepped currents to windings of a stepping motor, a position detector for obtaining a detected angle of a rotor of the stepping motor and a current controller for controlling the inverter. In a d-q rotation... | 02/01/2005 |
| 6836085 | Method and apparatus of controlling electric vehicle A method controls an electric vehicle which is so constituted as to drive a synchronous motor by way of a switch and an inverter circuit. A battery acts as a source of driving a controlling power. The synchronous motor has a permanent magnet acting as an outer rotor... | 12/28/2004 |
| 6806666 | Single-phase motor Disclosed is a single-phase motor including a stator, a rotor adapted to rotate when electric power is applied to the stator, a ring-shaped magnet coupled to the rotor to rotate along with the rotor; a parking magnet for stopping the rotor within an effective torque... | 10/19/2004 |
