Did You Know...
...that while attempting to develop a super strong glue, 3M employee Spencer Silver accidentally developed a glue that was so weak it would barely hold two pieces of paper together? However, his colleague Art Fry needed the glue. Fry sang with his church choir and marked the pages of his hymnal with small scraps of paper that often fell out. He used Silver's glue to hold the papers in place. Today we call this invention Post-it Notes.
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| Number | Title | Issue Date |
| 7355296 | Wind turbine generator system To shorten a startup interval to reach a synchronizing condition, a phase difference and an amplitude difference between the grid voltage and the stator voltage of one phase of a winding are obtained. The difference in amplitude is decreased prior to or in parallel ... | 04/08/2008 |
| 7292009 | Hybrid type working machine Simplifying the controller of hybrid type drive unit. The output of a generator driven by engine is connected directly to a motor 7 through a converter or switching circuit 10 without being charged on any battery. The output of each phase of the genera... | 11/06/2007 |
| 7289920 | Method and apparatus for capture of grid characteristics corresponding to fluctuation events The techniques described herein allow a wind turbine generator system to automatically capture voltage waveform data corresponding to a voltage disturbance event. Data corresponding to a period preceding the voltage disturbance event, during the event and a period o... | 10/30/2007 |
| 7279802 | Method in a wind power plant A method for preventing mechanical oscillation in a wind power plant includes determining wind speed, controlling a generator of the power plant with speed control when the wind speed is below a predefined limit to maintain the rotation speed of the generator below ... | 10/09/2007 |
| 7239113 | Method for reducing undesired currents in an electrical power generation system An electrical power generation system is provided, and a method of reducing undesired currents therein. The method includes the steps of delivering current via at least one variable frequency switching means, and adjusting a switching frequency of the at least one v... | 07/03/2007 |
| 7230399 | Vehicular generator-motor system A vehicular generator-motor 1 is composed of a rotor, a stator having three phase armature winding 2, and a converter 4. The rotor is provided with a field winding 3 for magnetizing a plurality of magnetic pole pieces 14a... | 06/12/2007 |
| 7218070 | System and method for braking a motor of a propulsion unit The present invention relates to a propeller drive arrangement for vessels used in water-borne traffic, and specifically to a propeller drive arrangement containing a propulsion unit, and to such an arrangement, which contains a propulsion unit, which is turnable re... | 05/15/2007 |
| 7208891 | Variable speed drive for a chiller system A variable speed drive with a boost converter is provided for a chiller system driven by an induction motor. The boost converter can be a diode or thyristor rectifier followed by a boost DC/DC converter or a three-phase pulse width modulated boost converter. The boo... | 04/24/2007 |
| 7205676 | Wind turbine generator system To shorten a startup interval to reach a synchronizing condition, a phase difference and an amplitude difference between the grid voltage and the stator voltage of one phase of a winding are obtained. The difference in amplitude is decreased prior to or in parallel ... | 04/17/2007 |
| 7202637 | Distributed control method The present invention provides an improved control method and apparatus allowing units arranged at different spaced apart locations to be controlled without the need for a high bandwidth link between the units and the controller. This allows a single controller to c... | 04/10/2007 |
| 7202626 | Variable speed drive for a chiller system with a switched reluctance motor A variable speed drive with a boost converter is provided for a chiller system driven by a switched reluctance motor. The boost converter can be a diode or thyristor rectifier followed by a boost DC/DC converter or a three-phase pulse width modulated boost converter... | 04/10/2007 |
| 7068015 | Wind power plant having magnetic field adjustment according to rotation speed A wind power plant where the driving shaft communicates with a synchronous generator (3) optionally through a gear (2) and with a transformer, if any, communicating through an AC/DC inverter 7 with an HVDC transmission cable 9. The synchr... | 06/27/2006 |
| 7042110 | Variable speed distributed drive train wind turbine system A variable speed wind turbine employing a rotor connected to a multiplicity of synchronous generators with wound field or permanent magnet rotors. A passive rectifier and an inverter are used for power transfer back to the grid. A Turbine Control Unit (TCU) commands... | 05/09/2006 |
| 7015595 | Variable speed wind turbine having a passive grid side rectifier with scalar power control and dependent pitch control A variable speed wind turbine having a passive grid side rectifier using scalar power control and dependent pitch control is disclosed. The variable speed turbine may include an electrical generator to provide power for a power grid and a power conversion system cou... | 03/21/2006 |
| 7015662 | Engine operated machine The invention makes an output sharing of an engine and an electric motor proper so as to suitably drive a load. When a throttle opening degree variation amount ΔV is within a ΔV1, an engine E can drive a power generator G at a rated revolution speed. A swit... | 03/21/2006 |
| 6995545 | Control system for a sputtering system A fault handling algorithm processes a plurality of fault status signals from a sputtering system in a period of time to generate at least one command signal for affecting the operation of a power generator. ... | 02/07/2006 |
| 6989640 | Actuator driving device of working machine A device, mounted on a hydraulic excavator, for allowing each of first and second electric motors (13), (14) to generate power by using electric power supplied from a power supply having a predetermined capacity, and actuating a boom cylinder (6... | 01/24/2006 |
| 6957990 | Electric houseboat An electric houseboat comprises a hull and a house-like structure mounted on the hull which includes at least one bedroom, a bathroom, and a kitchen. A Diesel generator comprises the sole power source for the houseboat. The operating temperature of the Diesel genera... | 10/25/2005 |
| 6949902 | Controller of rotating electric machine for vehicle A controller of a rotating electric machine for a vehicle has a magnetic field electric current command arithmetic device for commanding a magnetic field electric current by the command of a torque and electric power command arithmetic device, an electric power conv... | 09/27/2005 |
| 6940251 | Decoupling of cross coupling for floating reference frame controllers for sensorless control of synchronous machines A synchronous motor controller and method of controlling a synchronous motor without using rotor position sensors are provided. In a floating synchronous reference frame controller, phase currents are measured and a current Park vector is determined. The error betwe... | 09/06/2005 |
| 6924565 | Continuous reactive power support for wind turbine generators Real and reactive power control for wind turbine generator systems. The technique described herein provides the potential to utilize the total capacity of a wind turbine generator system (e.g., a wind farm) to provide dynamic VAR (reactive power support). The VAR su... | 08/02/2005 |
| 6919712 | Excitation control device and excitation control method A reference voltage of an output terminal of a synchronous machine is set according to a reactive current output from the synchronous machine, a reference voltage of the high voltage side of a transformer, and a phase compensation transfer function to quicken attenu... | 07/19/2005 |
| 6825630 | Machine tool, tool, and tool holder A longer life, low cost tool and tool holder enabling change of posture with respect to a spindle, having a high machining accuracy of a workpiece, and resistant to generation of vibration or heat, provided with a working tool for processing a workpiece, a motor hav... | 11/30/2004 |
| 6768277 | Gas turbine system and method for controlling the same In a gas turbine system having first power converter converting power system N AC voltage to DC voltage, second power converter converting the DC voltage into AC voltage, generator connected to second power converter's AC output and rotated by turbine and turbine co... | 07/27/2004 |
| 6107775 | Method and apparatus for limiting starting torque in a starter/generator A controller for a starter/generator used with an aircraft engine, includes means for monitoring field return current in a generator field winding; means for monitoring generator voltage; and microprocessor control means for adjusting generator field curr... | 08/22/2000 |
| 6023135 | Turbogenerator/motor control system A turbogenerator/motor control system having a plurality of proportional integral control loops including a fuel command control loop and a current command control loop. The exhaust gas temperature of the gas turbine of the turbogenerator/motor is maintai... | 02/08/2000 |
| 5977731 | Power system stabilizer and power system stabilization method A power system stabilizer (PSS) and a power system stabilization method estimate system construction parameters (k2 to k6) based on gains and phases of basic frequency components, and estimate an optimum frequency characteristic GPSS (jω) of t... | 11/02/1999 |
| 5903116 | Turbogenerator/motor controller A turbogenerator/motor controller with a microprocessor based inverter having multiple modes of operation. To start the turbine, the inverter connects to and supplies fixed current, variable voltage, variable frequency, AC power to the permanent magnet tu... | 05/11/1999 |
| 5903130 | Fail-safe regulator biasing circuit A controller for a starter/generator used with an aircraft engine, includes means for monitoring field return current in a generator field winding; means for monitoring generator voltage; and microprocessor control means for adjusting generator field curr... | 05/11/1999 |
| 5652485 | Fuzzy logic integrated electrical control to improve variable speed wind turbine efficiency and performance A control system utilizing fuzzy logic adaptive control to control the operation of a wind turbine driven electric power generator to control power generator speed and hence power frequency while maximizing the power output of the power generator. Wind tu... | 07/29/1997 |
| 5539286 | Motor vehicle electrical system having an electrical machine functioning as an on-board power supply generator A motor vehicle electrical system has an electrical machine with an on-board power supply generator function. The electrical machine can be operated, in a first mode, as an on-board power supply generator, having a regulator for setting the excitation cur... | 07/23/1996 |
| 5298842 | Thermal protection for locomotive main traction alternators In a thermal overload protection system three system variables are sensed and provide the inputs required for a calculation conducted in real time at one second intervals. The system variables include ambient inlet air temperature to the alternator, alter... | 03/29/1994 |
| 4143280 | Control system for a tertiary winding self-excited generator A control system for a self-excited alternator which includes an auxiliary winding adapted to supply excitation to the alternator field winding incorporates a circuit for supplementing field excitation when the available energy from the auxiliary winding ... | 03/06/1979 |
| 4007407 | Turbo-electric marine power plant and method of regulating the same In a marine power plant which has an rpm-regulatable heavy gas turbine, a propulsion generator driven by the turbine, a propulsion motor driven by the generator and a fixed propeller driven by the motor, the turbine rpm is regulated as a function of the p... | 02/08/1977 |
| 3953775 | Propulsion control system for electrically powered vehicles Propulsion control system for electrically powered vehicles, typically heavy duty off-road type work vehicles having electric motor driven wheels. In embodiment shown, power is supplied from direct current generator driven by internal combustion engine. M... | 04/27/1976 |
| 3937001 | Watch movement driven by a spring and regulated by an electronic circuit An electronically regulated watch movement comprising a time-wheel mechanism driven by a drive, a generator being coupled to the drive via at least a portion of the time-wheel mechanism and with substantial gear reduction. The generator includes a rotor w... | 02/10/1976 |
