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"That the automobile has practically reached the limit of its development is suggested by the fact that during the past year no improvements of a radical nature have been introduced."
Scientific American ; Jan. 2 edition, 1909
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| Number | Title | Issue Date |
| 8159851 | Matrix converter A matrix converter includes a matrix converter main circuit, an input voltage detector group configured to detect an input voltage of an alternating current source, a gate driver configured to drive a bidirectional switch, and a controller having a pulse width modul... | 04/17/2012 |
| 7821802 | Control method for direct power converter A power converter directly converting an AC voltage into an AC voltage of any desired magnitude and frequency by turning bidirectional switches ON and OFF without employing any energy buffer, where the peak values of output phase voltage command values are limited, ... | 10/26/2010 |
| 7339809 | Systems and methods for electrical power regulation and distribution in aircraft The present invention comprises systems and methods for electrical power regulation and distribution. In an embodiment, a system includes a modulator coupled to the source that receives an unregulated output waveform and is operable to produce a first composite wave... | 03/04/2008 |
| 7332882 | Motor drive device that combined charge controller A voltage detector is connected to a connection terminal connected to one phase of an AC output of an inverter through a diode. A removable charge power supply is connected to said connection terminal and another connection terminal. A charge-power-supply connection... | 02/19/2008 |
| 7319576 | Apparatus and method for providing differential protection for a phase angle regulating transformer in a power system Provided is an apparatus and method for providing differential protection for a phase angle regulating transformer having a load side and a source side in a three-phase power system. The method includes calculating a first positive sequence component and a first neg... | 01/15/2008 |
| 7280938 | Method for determining a negative sequence component The invention relates to a method for determining properties of a negative sequence component of a space vector quantity in an electrical network. The method according to the invention includes the steps of determining on the basis of the properties of an ellipse fo... | 10/09/2007 |
| 7212421 | Combination feedback controller and power regulator using same A combination controller incorporates features of a classic controller and a state space controller to function as a hybrid controller unit. The PID portion of the classic controller regulates the steady state error and is separated from the pulse width modulated co... | 05/01/2007 |
| 6972976 | Compensation method for a voltage unbalance The invention relates to a method for compensating for a voltage unbalance in an electrical network, which is fed by using an apparatus based on controlling a flux linkage vector or a voltage vector. Concerning the apparatus based on controlling the flux linkage vec... | 12/06/2005 |
| 6954040 | Method of controlling a reciprocating linear motor A free piston gas compressor comprising a cylinder, a piston reciprocable within the cylinder and a reciprocating linear electric motor derivably coupled to the piston having at least one excitation winding. A measure of the reciprocation time of the piston is obtai... | 10/11/2005 |
| 6760239 | Method for controlling a matrix converter A method for controlling a matrix converter with nine bidirectional power switches arranged in a 3×3 switch matrix is described. Switching states of a modulation period are each calculated with associated time intervals by using a space vector modulation method. Ac... | 07/06/2004 |
| 6343021 | Universal input/output power supply with inherent near unity power factor An electronic method and apparatus are described for an isolated, universal input, power supply in the form of a single-ended resonant converter that utilizes capacitive energy storage versus magnetic energy storage, for converting an ac or DC input volta... | 01/29/2002 |
| 6310901 | Automated AC filament universal laser power controller in a gas ion laser system and method A power supply is provided for use in a laser system including a gas ion laser tube which requires a filament voltage provided by an output section of the power supply. The filament voltage provided should not exceed a maximum AC filament voltage specifie... | 10/30/2001 |
| 6018466 | Electronic signal conditioner An electronic signal conditioner (ESC) (10) that can be designed to operate a differential capacitive load (90) or a single-ended capacitive load (92). The ESC (10) is disclosed in four design configurations. In the first design, the ESC (10) employs a pa... | 01/25/2000 |
| 5630155 | Portable computer system with mechanism for accumulating mechanical energy for powering the system An embodiment of the the present invention is a computer system comprised of a main computer circuit having an interruptible CPU, a control program stored in memory connected to the CPU with interrupt procedures, and a power supply that has a mainspring a... | 05/13/1997 |
| 5317500 | Active no-break power transfer control for a VSCF power generating system An improvement in a control for a DC link power converter includes a phase command signal generator responsive to DC power on a DC link wherein the phase command signal generator develops a phase command signal for a control of the power converter whereby... | 05/31/1994 |
| 4905134 | Paralleling method and control for a VSCF system Prior variable speed constant frequency (VSCF) system controls which operate the VSCF system while it is coupled in parallel with an external AC source across a load have controlled inverter output voltage based only upon the reactive current level suppli... | 02/27/1990 |
| 4858100 | Electric power converter An electric power converter, in which a plurality of converters convert a first electric power having a first frequency into a second electric power having a second frequency, and the second electric power is supplied to a load such as an electric motor, ... | 08/15/1989 |
| 4777581 | Modulation method and apparatus for static power frequency changers The performance of the cycloconverter when used to drive an induction motor is at present limited because of inadequate methods of modulating the thyristor conduction angles. The main problems are: low maximum frequency due to subharmonics; voltage distor... | 10/11/1988 |
| 4772994 | Power source using high-frequency phase control A power source using high-frequency phase control possessing an ability to cause the transfer of electric power between a power source side and a load side to be made through a high-frequency transformer and to effect control of the output voltage by subj... | 09/20/1988 |
| 4764859 | Method and apparatus for controlling circulating-current type cycloconverter A current-circulating cycloconverter includes a positive converter and a negative converter connected in anti-parallel with each other through a DC reactor. A load is connected to an intermediate tap of the DC reactor. When a load current flowing to the l... | 08/16/1988 |
| 4680695 | Cross coupled current regulator A current regulator for a variable frequency power supply includes a proportional plus integral circuit that produces a composite control output signal for each phase. To improve the performance of the current regulator at higher frequencies, the composit... | 07/14/1987 |
| 4675802 | Three-phase-to-three-phase power converter A 3-phase-to-3-phase power converter is intended to control the output voltage and current so as to provide a 3-phase sinusoidal wave which is controlled in compliance with the input voltage. The main circuit has a switching period shorter than 30° of th... | 06/23/1987 |
| 4658346 | Apparatus for co-generation of electric power Apparatus for converting relatively high, variable frequency, variable amplitude electrical power into substantially constant amplitude and substantially constant, relatively lower frequency power of a preselected waveform. The power source signal is divi... | 04/14/1987 |
| 4648022 | Matrix converter control system A three-pulse UFC system uses three groups of three bilateral switches controlled according to a switch polarity pattern to generate AC currents to a load, and a deadband hysteresis having upper and lower limits is used to maintain the load current so as ... | 03/03/1987 |
| 4639851 | Method and apparatus for firing angle control of series connected thyristor switches To eliminate thyristor failure due to voltage imbalance across series-connected thyristors during reverse voltage recovery caused by current discontinuity under continuous pulse application to the thyristors, the continuous pulse is discontinued after a t... | 01/27/1987 |
| 4590548 | A.C. supply converter A direct a.c. supply converter for converting an N (ࣙ2) phase input voltage system into an a.c. output voltage system of different frequency, amplitude, and/or phase using width-modulated contributions from the phases of the input voltage system to prod... | 05/20/1986 |
| 4555755 | AC Current control system In an AC current control system for controlling multi-phase AC currents supplied from a power converter to a load, the currents are detected and coordinate-transformed into orthogonal two-axis current values id, iq in a rotating coor... | 11/26/1985 |
| 4538220 | Adjustable frequency AC motor drive using an unrestricted frequency changer system In an unrestricted frequency changer (UFC) the control pulses are generated by the intersection of a reference ramp of controllable slope and frequency with a succession of timing ramps characterizing the succession of phase voltages at the input of the U... | 08/27/1985 |
| 4510399 | Demodulator circuit for parallel AC power systems A demodulator circuit utilizes a switching demodulation technique to detect the real and reactive components of load current unbalance in a parallel source alternating current power system. A signal representing load current unbalance is selectively switc... | 04/09/1985 |
| 4480301 | Method and apparatus for controlling a pulsed frequency converter A system for forming addressing signals for addressing respective converter switches of a frequency converter; the frequency converter being of the type which is provided with DC input terminals for receiving electrical energy which is conducted to phase ... | 10/30/1984 |
| 4349867 | Control apparatus for a cycloconverter A control apparatus for a cycloconverter includes m sets of bridge converters connected between the input terminals of an m-phase load (mࣙ3) and is applied for a cycloconverter of which the common connection point of the bridge converters is disconnecte... | 09/14/1982 |
| 4225911 | Apparatus and method for reducing overvoltage transients on the outputs of a VSCF system An apparatus and method for reducing the overvoltage transients present on the alternating current power signals provided by the cycloconverters of a variable speed constant frequency (VSCF) system during the first several cycles of the alternating curren... | 09/30/1980 |
| 4012677 | Speed control for electrically propelled traction vehicles 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 ... | 03/15/1977 |
| 4008428 | Circuit arrangement with a number of frequency converters, particularly Y-connected direct frequency converters A circuit arrangement is disclosed having an odd number of Y-connected frequency converters. The control units of the frequency converters are associated with current regulators, all of which are addressed by an additional common reference value. In accor... | 02/15/1977 |
