Class 307/73 - Differing frequencies

Subclass of Class 307 - Electrical transmission or interconnection systems
Definition: Subject matter in which the diverse sources are different
No. of patents: 34
Last issue date: 02/14/2012

Number	Title	Issue Date
8115341	Power converter having airplane power source frequency detector A power converter having an aircraft power source detector configured to limit the amount of power that can be drawn by the power converter when utilized in an aircraft. The power converter may detect an artifact of the aircraft power source, such as the 400 Hz ripp...	02/14/2012
7652394	Responsive electricity grid substation There is provided an electricity grid, system having a substation connecting two grid parts, preferably at different levels in the grid hierarchy, wherein flow control means is provided for controlling the flow of electricity between the two parts in dependence on t...	01/26/2010
7566992	Method and apparatus for operation of a power station A power station comprises a power-consuming shaft run on which a motor and a compressor are arranged, as well as a power-emitting shaft run on which a generator and an expansion machine are arranged. The compressor feeds a compressed fluid into a storage volume. The...	07/28/2009
7417337	Method and system for facilitating no-break power transfer An improved method and system for facilitating no-break power transfer between an APU and a main engine includes determining a required APU speed for conducting power transfer based on various APU operating parameters, such as engine speed, fuel, environmental tempe...	08/26/2008
7418314	Methods and apparatus for providing and distributing standby power Aspects of the invention are directed to power distribution systems and methods for distributing power from a primary power source and a backup power source to a load. In one particular aspect, a power distribution system includes a first input to receive input powe...	08/26/2008
7362007	Hybrid uninterruptible power supply system An apparatus, system, and method for supplying an uninterruptible power source to a dual power device capable of being alternately powered through either a primary power input connected to a primary power source or a secondary power input connected to a secondary po...	04/22/2008
7349446	Signal superimposition A method and apparatus are provided in which control data for a generator system is multiplexed onto a synchronization signal. ...	03/25/2008
7291938	Power supply apparatus and method based on parasitic power extraction Power supply apparatus and method based on parasitic power extraction is disclosed. Power is extracted from signals that are inbound and/or outbound from an equipment. The extracted power is converted to dc voltages for a device associated with the equipment. The po...	11/06/2007
7254465	No-break-power-transfer control system for variable frequency electrical power systems A method and apparatus for executing a no-break power transfer between an electrical power generator powered by an auxiliary power unit (APU) and an electrical power generator powered by an aircraft main engine. The method comprises sending a power transfer command,...	08/07/2007
7239044	Enhanced distributed energy resource system A power transmission system including a direct current power source electrically connected to a conversion device for converting direct current into alternating current, a conversion device connected to a power distribution system through a junction, an energy stora...	07/03/2007
7142950	Methods and apparatus for providing and distributing standby power Aspects of the invention are directed to power distribution systems and methods for distributing power from a primary power source and a backup power source to a load. In one particular aspect, a power distribution system includes a first input to receive input powe...	11/28/2006
6977449	Frequency converter and drive for electric motor A charging contactor and charging resistor of a capacitor battery in a prior art intermediate circuit of a frequency converter are replaced with three semiconductor switches connected between a three-phase voltage supply and a capacitor battery. When the frequency c...	12/20/2005
6806589	No break electric power transfer system A no break power transfer system that is particularly useful onboard an aircraft ensures that there is an appropriate frequency match between the outputs of different power supplies. A frequency adjuster between an auxiliary power unit and a load alters the frequenc...	10/19/2004
6696773	Vehicle generator control system A generator control system of a vehicle AC generator includes a field coil, a first polyphase armature winding, a second polyphase armature winding, a first rectifier connected to the first armature winding and a second rectifier connected to the second a...	02/24/2004
6037725	Two step power output motor An electrical control system for an induction motor for achieving optimum efficiency at both full and partial loads at markedly reduced electrical components costs while maximizing reliability over the range of load, and for achieving a two step motor pow...	03/14/2000
5939800	Aircraft electrical power system including air conditioning system generator An electrical power system for an aircraft includes an ac generator bus, an air conditioning system ("ACS") generator and a main engine generator. The ACS generator supplies primary ac power to the bus while the frequency of the ac power is within a frequ...	08/17/1999
5808449	Method and apparatus for detecting islanding operation of dispersed generator A method for detecting islanding operation of a rotating-machine type dispersed generator. The dispersed generator is interconnected with a main electric source through a circuit breaker to constitute an electric power system. The estimating method is imp...	09/15/1998
5773964	Output and torque control of an automotive alternator An apparatus for controlling the output and torque of a synchronous alternator has a controlled bridge rectifier operable off synchronous for rectifying the alternating output and establishing a desired phase relationship between the alternating voltage a...	06/30/1998
5764502	Integrated electric power system An electric power generation system having two main sources of ac power comprises a first and a second main power conversion and distribution unit (MPCDU1, MPCDU2), each electrically coupled to one of the sources of ac power. The MPCDUs controllably suppl...	06/09/1998
5761073	Programmable apparatus for synchronizing frequency and phase of two voltage sources A programmable autosynchronizer for use with a system having generator and bus voltages and having a breaker circuit for connecting the generator and bus voltages to each other. The autosynchronizer synchronizes the frequency and phase of the generator an...	06/02/1998
5640060	Apparatus for synchronizing frequency and phase of two voltage sources An autosynchronizer for use with a system having generator and bus voltages and having a breaker circuit for connecting the generator and bus voltages to each other. The autosynchronizer synchronizes the frequency and phase of the generator and bus AC vol...	06/17/1997
5627737	Power inverter for use in system interconnection A power inverter for use in the system interconnection of a direct-current supply with a commercial alternating-current supply includes an inverter circuit and a filter circuit. Feedback signals affecting the frequency of an output to be produced by the i...	05/06/1997
5596492	Method and apparatus for de-centralized signal frequency restoration in a distributed UPS system An Uninterruptible Power Supply (UPS) for de-centralized operation in a distributed UPS system is described. The UPS system includes a number of UPS units that do not have communication links between them and therefore operate in a de-centralized manner. ...	01/21/1997
5589864	Integrated varactor switches for acoustic ink printing An integrated varactor and piezoelectric device for an acoustic ink jet ejector includes a substrate having a first surface, the silicon substrate forming a first electrode, an epitaxial layer formed over the first surface of the silicon substrate, a sili...	12/31/1996
5521941	Automatic threshold control for multi-level signals Symbol recovery for multi-level digital signals has traditionally been difficult because of the nature of the eye pattern output by the discriminator (103), and especially its response to a noisy or impeded signal environment. This method and apparatus fo...	05/28/1996
5461263	Method of phase synchronization between two AC signals An uninterruptible power supply for supplying a load with AC output power generates the AC output power from an AC input source when the AC input source is within settable voltage limits and transfers to generating the AC output power from an auxiliary so...	10/24/1995
5355024	Solid state frequency converter capable of misaligned parallel operation A ground power unit capable of no-break power transfer includes a rectifier for converting power from commercial mains to direct current, a switching circuit, a power transformer, and a pattern generator for controlling the operation of the switching circ...	10/11/1994
5103110	Programmable power supply A programmable power supply having a plurality of channels wherein each channel is adapted to output a selectable DC voltage, AC voltage, DC current or AC current. Each channel is adapted to select a DC reference signal or an AC reference signal and to sc...	04/07/1992
5090035	Linear feedback shift register A linear feedback shift register comprises a shift register formed of first to (n)th flipflops cascaded in such a manner that an output of a (i)th flipflop is connected to an input of a (i+1)th flipflop, where 2ࣘn and 1ࣘiࣘ(n-1). First to (n)th outpu...	02/18/1992
5051603	Method and apparatus for matching turn-off times of parallel connected semiconductor switching devices A power switching system for controlling the conductivity of a plurality of thyristors of the gate turn-off type (GTOs) which are connected in parallel between two power sources by gradually introducing a time compensation to force the times of turn-off o...	09/24/1991
4503371	Mass driver circuit for weaving looms A drive motor for each loom is selectively connected to a given commercial frequency power source for high speed rotation at normal running of the loom and to a low frequency power unit for low speed rotation at inching operation, thereby assuring accurat...	03/05/1985
4376471	Emergency apparatus for elevator An emergency apparatus for elevator which converts a DC power into an AC power by an inverter device in an emergency state to feed the AC power to an AC traction motor and an AC motor for door-opening and closing which have different rated voltages so as ...	03/15/1983
4362971	Power supply for arc discharge devices This application discloses circuits for use with arc discharge devices wherein a D.C. or A.C. high frequency, high voltage source is provided in conjunction with either a low frequency or D.C. voltage source. The high frequency, high voltage circuit is a ...	12/07/1982
4057750	Apparatus and method for sustaining the operation of HID lamps To prevent high-intensity-discharge (HID) lamps from extinguishing for prolonged periods due to a power interruption or an appreciable drop in line voltage, a rectifier-battery combination provides standby power for operating a high-frequency inverter. Th...	11/08/1977

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Class 307/73 - Differing frequencies