Matches 1 - 50 out of 171 1 2 3 4 >
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7598720 Method and system for detecting the phase of wiring of an unknown phase voltage relative to a reference phase voltage  
A system detects the wiring phase of an unknown phase voltage at a remote location relative to a reference phase voltage at a reference location in an electrical power distribution system having a...
7589516 Poly-phase electric energy meter  
A poly-phase electric energy meter comprises a front-end that converts analog current input signals and analog voltage input signals to digital current and voltage samples and a micro-controller...
7474087 Energy meter system and method for calibration  
An energy meter device includes a first analog/digital transformer having an input configured to provide a signal derived from a voltage and a second analog/digital transformer having an input...
7443704 AC high voltage detecting device  
An AC high voltage detecting device includes a high voltage power supply (HVPS) to convert a low voltage into an AC high voltage, a rectifier to rectify the converted AC high voltage into a...
7429855 Regenerative load bank with a motor drive  
An electronic power converter for a generator under test that emulates resistive and inductive-capacitive (LC) loads and regenerates energy from the generator back to a utility grid.
7414329 Polyphase power distribution and monitoring apparatus  
A polyphase power distribution and monitoring apparatus having sets of outputs for each phase of power and monitors for each phase of power disposed in the housing. Each monitor provides a visible...
7294997 Electrical meter system with color coding features  
A communication system between a plurality of electrical loads and at least one electrical measurement device is configured with a plurality of wires grouped in pairs. Each pair of wires is...
7218122 Power disturbance generator  
An apparatus selectively generates a disturbance in a three-phase supply voltage provided to a load. The apparatus includes input connections for receiving a first phase voltage, a second phase...
7205756 Unbalanced current detection  
An unbalanced current detection circuit determines when a multi-phase, normally-balanced load is unbalanced. The detection circuit of the present invention includes a plurality of current-squaring...
7109699 Long range alternating current phasing voltmeter  
A long-range wireless phasing voltmeter having a high impedance AC voltmeter in series between two high impedance probes. Shielding surrounds and electrically isolates the voltmeter and probes that...
7106045 Apparatus for a simplified power disturbance indicator gage with learning capability options  
Disclosed is a simplified electrical power disturbance gage. The gage is capable of measuring high-speed anomalies on power mains. The gage includes elements capable of detecting power line...
6983211 Revenue meter bayonet assembly and method of attachment  
A method and arrangement are disclosed for attaching one or more electrical bayonet-type blades to a circuit board with the bayonets being used to receive voltage and current signals from the...
6809509 Electrical monitoring system  
An electrical sensing device that includes a support and sensors supported by the support in a fixed spatial relationship.
6714000 Method for monitoring power and current flow  
A method for remotely monitoring the magnitude and direction of net electrical power and current flow to or from a facility over a prolonged period of time. The method includes detecting and...
6690151 Phase detection circuit  
An apparatus is described for determining whether the power applied to two outlets is in phase or out of phase. Two plugs are used, one for engaging each of the outlets. A circuit coupled to both...
6642702 Detection circuit for maximum value of three phase signal and detection method of the same  
A detection circuit for a maximum amplitude value of a 3-phase signal wherein the three phase-signals having a phase difference of 120° from each other is converted to sampling data of digital...
6614217 Power supply negative phase detecting circuit  
A power supply negative-phase detecting circuit ( 10 ) for electronic equipment ( 12 ) using a three-phase AC power supply source includes a pulse generator ( 13 ) for generating a first pulse...
6590397 Line differential protection system for a power transmission line  
In a three terminal power line current differential protection system, all three phase current values (I A , I B and I C ) are obtained from all three terminals. The current values for each phase...
6559652 Method of statistically balancing current transformer measurements for differential busbar protection  
The method of correcting measurements is intended to limit the risk of unnecessary tripping of a differential phase current protection system that computes the vector sum of the currents of an area...
6541954 Circuit apparatus for sensing line conditions in a three phase power line  
The present invention is a power monitoring circuit for sensing line conditions in a three phase power line. In the circuit a plurality of series connected power supplies for powering various...
6507184 Methods and apparatus for differential current measurement in a three-phase power system  
A measure of the current through a first terminal of a device in a three-phase power system is obtained for each phase of the system. A measure of the current through a second terminal is also...
6483291 Apparatus for measuring electrical power consumption  
An apparatus for measuring electrical power consumption. An apparatus for measuring electrical power consumption is provided. The total power is obtained by multiplying the instantaneous voltage of...
6456097 Fault current detection method  
A method for measuring the impedance of electrical distribution equipment includes: applying a voltage at a first selected frequency to electrical distribution equipment, waiting a delay time for...
6397157 Method and apparatus for real time measurement of three phase electrical parameters  
An apparatus and method for determining, in real time, the key parameters of a three phase system electrical generator's output. A pair of reference vectors in quadrature (orthogonal) is...
6377037 Watt-hour meter with digital per-phase power factor compensation  
A watt-hour meter employs a power factor compensation technique that inserts a delay into the digitized current or voltage sample stream. An exemplary embodiment of the present invention includes...
6373238 Three-phase electrical power measurement system including three transformers and a measurement circuit to calculate the power thereof  
A measurement system includes a first transformer enclosed within a first housing and magnetically linked to a first cable where the first transformer senses changing current within the first cable...
6291986 Insert for measuring current in conductors within an electrical enclosure  
A conduit apparatus for an electrical enclosure that allows safe, convenient access for current measurement of circuits therein is provided. The conduit apparatus has one or more non-magnetic...
6147616 Automatic power interruption and re-supply relay for an electric power line  
The present invention provides a digital automatic power interruption and re-supply relay for performing detection and comparing operation to inform a state of an accident with voice and numerals...
6112159 Robust electrical utility meter  
The present invention includes an electrical utility meter operable to measure power consumption. The method detects and compensates for one or more wiring errors that affects the power consumption...
6112158 Service type recognition in electrical utility meter  
Disclosed is a method and arrangement for use in an electrical utility meter, the electrical utility meter operable to be connected to a plurality of electrical service types. The arrangement is...
6097182 Electrical energy meter for 3-wire delta service  
An electronic energy meter for use with a 3-wire delta service having a resistive voltage divider for sensing and scaling the line voltages is disclosed. The resistive voltage divider includes...
6008711 Method and arrangement for securing a current transformer to an electric utility meter housing  
An arrangement for securing a current transformer to an electric utility meter housing. The arrangement includes a utility meter base plate which forms a portion of the electric utility meter...
6008635 Electricity meter  
An electricity meter with differentiating input converters, in particular current converters, attains improved signal processing by providing a respective analog filter, in particular a low-pass...
5903145 Universal electronic energy meter for use with 4-wire standard services  
A universal electronic energy meter for measuring electrical energy usage of a circuit having a 4-wire service is disclosed. The universal meter is operable with both 4-wire wye and 4-wire delta...
5834932 Watthour meter system  
An electrical energy consumption measuring system is disclosed which includes a watthour meter, a meter socket, a set of voltage transformers and two plugs. The meter is energized when it is...
5798932 Methods and apparatus for removing error due to decaying offsets from measured power system currents  
A digital decaying current offset correction method and apparatus, in one aspect, separates the requirements of detecting fault existence from the requirements of detecting fault location. Once the...
5751132 Electric motor monitoring circuit  
An electric motor monitoring circuit apparatus for an electric motor has a three phase electric motor having an electric motor starter circuit. An insulation monitoring circuit is coupled to the...
5691634 Wye service power meter  
A device for monitoring power in a wye power service having three phases includes a sampling element arranged and configured to sample a current value and a voltage value from each of the three...
5652505 Power consumption measurement device for a multiphase alternating current system  
Disclosed is a watt/watthour meter which is capable of automatically correcting incorrect connections between the apparatus and a multiphase AC system. Each power line of the multiphase system is...
5623201 3-phase power meter having a display board  
A 3-phase power meter for measuring and displaying a set of physical quantities of R-, S- and T-phase electric power generated by a 3-phase AC alternator includes a display unit for displaying the...
5574362 Electrical energy measuring and metering device  
A metering device includes a standard AC energy meter, and a conversion circuit. The conversion circuit measures the voltages and currents of an installation incompatible with the functional...
5548207 Missing phase detector  
A missing phase detector circuit which monitors the ac three-phase output voltages of power equipment or sources and produces an output signal in the event a missing ac phase is detected. The...
5517106 Method and apparatus for digitally measuring electrical power  
A method and apparatus for digitally measuring electrical energy consumption parameters from a transmission line carrying alternating current. Current flowing in the conductor is sampled at...
5508617 Electric power measuring apparatus and method  
The current invention is directed to a method of measuring an electric power and in particular to a precise power measurement by measuring a current and a voltage of high-frequency distortion...
5467011 System for detection of the phase of an electrical signal on an alternating circuit power line  
A data transmission system for power line carriers includes a transmitter which generates a stable carrier frequency at a bandwidth of less than one hertz. The transmitter is connected to the power...
5442279 Apparatus and method for detecting power of a three phase alternating current system  
An electric power detector for a three-phase AC voltage supply which measures the current of one phase and the voltage between the one phase and another phase and computes the phase difference...
5426590 Device for numerical computation of a symmetrical component of an electtical quantity of a three-phase power system and relay incorporating it  
The computing device comprises non-recursive, digital filters, with finite impulse response, computing, from samples taken over a period of the power system, for at least two distinct phases, two...
5410243 Three-phase collected type optical current transformer  
A three-phase collected type optical current transformer having a common hermetically sealed container miniaturized in its radial direction. The common hermetically sealed container incorporating...
5408176 Monitoring and fault protection of high voltage switch yards  
The currents flowing through high voltage conductors in a network or switchyard are monitored by magnetic field sensors in the form of air-cored epoxy-filled coils which are electrostatically...
5378979 Method and apparatus for efficiently computing symmetric sequence signals in a three phase power system  
A real time three-phase analyzer stores digitized values of the signals of the three-phase circuits in memory so that they may be addressed according to circuit and sample number. Positive,...
Matches 1 - 50 out of 171 1 2 3 4 >