A system and method for encouraging an energy user to conserve energy by providing the user with musical feedback describing their energy use as a musical piece. Various musical parameters of the musical piece may be manipulated to describe higher- or lower-than-expected energy use, in order to encourage the user to conserve energy. A visual animation may also be added to the musical piece to illustrate it further.

A three-phase power meter can monitor power on both 3-wire and 4-wire power lines. The power meter measures at least two voltages between phase conductors of the power line, and at least one voltage between a phase conductor and a neutral conductor of the power line when the neutral conductor is available. Using at least some of the measured voltages, the power meter can then operate in a first mode when coupled to a 3-wire power line to determine power on the power line based on the measured voltages, or operate in a second mode when coupled to a 4-wire power line to determine power on the power line based on the measured voltages.

A diagnostic system for a home appliance, and a method for diagnosing the home appliance, the method according to one aspect including collecting consumed electric power information of the home appliance by a power measuring part; transmitting the collected electric power information to an external server; and receiving operation state information of the home appliance analyzed from the external server by the home appliance.

This document relates to electricity management using modulated waveforms. One example modulates electricity to obtain modulated electricity having at least two different alternating current frequencies including a first alternating current frequency and a second alternating current frequency. The example delivers the modulated electrical power having the at least two different alternating current frequencies to multiple different electrical devices, including a first electrical device configured to utilize the first alternating current frequency and a second electrical device configured to utilize the second alternating current frequency. The modulated electricity can be delivered at least partly over an electrical line shared by the first electrical device and the second electrical device.

A power measurement system, including a voltage measurement circuit having a resistive network comprising first and second resistors connected in series on a first single substrate, and a feedback amplifier having an input in electrical communication with a point between the first and second resistors, and an output in electrical communication with the second resistor in a feedback configuration to output an attenuated voltage signal, and a transresistance current measurement circuit including a current transformer to transform an input primary current into a secondary current, a plurality of amplifiers configured in a cascading arrangement, and a feedback resistor configured in parallel with the cascaded amplifiers such that the combined gain of the cascaded amplifiers directs substantially all of the secondary current through the feedback resistor, wherein the system is selectively switchable between a voltage measurement mode and a current measurement mode.

A monitor circuit for monitoring a CUT (Circuit Under Test) is provided. The monitor circuit includes a power switch and a current meter. The power switch is coupled between a supply voltage and the CUT. The current meter is coupled in parallel with the power switch. The current meter is configured to detect a current through the CUT.

Described herein are methods and systems for remote sensing to derive a calibrated power measurement for a power distribution point. Magnetic field sensors of a sensor module sense a magnetic field emitted by the power distribution point. A first processor generates an uncalibrated power measurement for each magnetic field sensor, the uncalibrated power measurement derived from the magnetic field sensed by the magnetic field sensor and a voltage carried by the power distribution point. A second processor determines a response of each magnetic field sensor to a known power load being drawn through the power distribution point. The second processor derives a transfer function using the response of each magnetic field sensor to the known power load. The second processor applies the transfer function to the uncalibrated power measurement for each magnetic field sensor to generate the calibrated power measurement for the power distribution point.

An intelligent electronic device for monitoring and determining an amount of electrical power usage by a consumer, or end user, and for providing broadband Internet access to the consumer. The intelligent electronic device includes at least one sensor coupled to an electric circuit configured for measuring at least one power parameter of the electrical circuit and generating at least one analog signal indicative of the at least one power parameter; at least one analog to digital converter coupled to the at least one sensor configured for receiving the at least one analog signal and converting the at least one analog signal to at least one digital signal; a processor configured for receiving the at least one digital signal and calculating energy consumption in the electrical circuit; and a gateway configured for receiving data transmissions imposed on the electrical circuit and for demodulating the imposed data transmission for providing data communications.

An electric power meter capable of monitoring a contact status of a latch relay, comprises: a latch relay having a pair of primary coils and a secondary contact, the secondary contact operable to a closed position or an open position, the primary coils configured to provide a magnetic force to open or close the secondary contact; and a meter controller configured to determine that the latch relay is in a closed position when the input voltage of the primary coils is substantially equal to the output voltage of the secondary contact with a predetermined allowable error range, and configured to determine that the latch relay is in an open position when the output voltage of the secondary contact has not been input, even if the input voltage of the primary coils has been input.

A duplex system measuring and outputting at least one of a voltage and current is provided. A first measurement device measures at least one of the voltage and current. A second measurement device measures at least one of the voltage and current. A control device is disconnected from the first measurement device and performs a changeover to the second measurement device when the first measurement device abnormally operates. A filter filters a second measurement value of the second measurement device based on a first measurement value of the first measurement device to output a filtered value.