Abstract: The computational resources of a digital power meter can be reduced by utilizing an interrupt requested in anticipation of interrupt latency to perform real-time tasks, an approximation of a root mean square load current at an earlier time to compensate for a phase shift between the load current and the current transducer output, and an amplitude that is neither zero nor maximum to distinguish the cycles of a harmonically distorted waveform.

Abstract: A protection device for monitoring current in a power cable to an electrical device and for controlling a remotely located starter for the electrical device in response to a system controller. The device includes a transformer magnetically linked with the power cable to produce a voltage signal in response to the presence of a changing current within the power cable. An input circuit located in a single housing together with the transformer is electrically connected to the transformer so as to receive the voltage signal. The input circuit produces, in response to the voltage signal, either a first signal or a first circuit condition at the output terminal of the input circuit, representative of the changing current in the power cable. A switch circuit also in the same container with the transformer has a terminal for sensing either a second signal or a second circuit condition of the remotely located system controller.

Abstract: A protection device for monitoring current in a power cable to an electrical device and for controlling a remotely located starter for the electrical device in response to a system controller. The device includes a transformer magnetically linked with the power cable to produce a voltage signal in response to the presence of a changing current within the power cable. An input circuit located in a single housing together with the transformer is electrically connected to the transformer so as to receive the voltage signal. The input circuit produces, in response to the voltage signal, either a first signal or a first circuit condition at the output terminal of the input circuit, representative of the changing current in the power cable. A switch circuit also in the same container with the transformer has a terminal for sensing either a second signal or a second circuit condition of the remotely located system controller.

Abstract: The data storage and processing resources required for an electric meter are reduced by basing the selection and application of phase error correction on a root mean square load current flowing through the meter.

Abstract: A pneumatic controller for controlling a device.

Abstract: A combination current sensor and relay has an improved housing. In one aspect, the housing includes light emitting diodes on an upper surface that indicate open circuit and short circuit conditions. In another aspect, the housing includes a securement structure for a circuit board that includes the transformer and switches for device operation, together with aligned openings therein for routing wires to external devices. In another aspect, a multiple position switch is included on the upper surface that indicates multiple modes of operation of the device. In another aspect, the housing may be assembled in multiple parts by affixing a first portion to a support, a circuit board to the first portion, and a second portion to the first portion. In another aspect, the housing is suitable for engagement to alternatively a junction box and a duplex box. In another aspect, the configuration of the upper surface provides usability advantages.

Abstract: A power monitoring system for electrical panels providing power, received from one or more power sources, to multiple current conductors. The power monitoring system preferably includes a plurality of sensors affixed to a support. A portion of each sensor defines an opening through which a current conductor may be extended.

Abstract: Separable toroidal segments reduce the size of a sensing transformer that can be installed on an electrical conductor while connected to a device.

Abstract: A status indicator indicates an operating state, including an electrical malfunction, of an electrical load that is located and controlled from locations remote from a monitoring location.

Abstract: A system for controlling an electrical device that includes an enclosure and an optical signal.

Abstract: A current sensor that includes a pair of segments. Each of the segments includes magnetically permeable cores that can be joined together. A winding is used to substantially encircle one of the cores.

Abstract: A power monitoring system for electrical panels providing multi-phase power, with multiple current sensors. The disclosed power monitoring system preferably determines the instantaneous power provided to each of multiple loads by sensing the potential and phase of each conductor that supplies power to one or more of the respective loads.

Abstract: An electricity metering method and apparatus is provided for determining the phase of first waveform relative to a harmonically distorted, second waveform having cycles temporally distinguished by an occurrence of an amplitude that is neither zero amplitude nor a maximum amplitude of said waveform.

Abstract: A protection device for monitoring current in a power cable to an electrical device and for controlling a remotely located starter for the electrical device in response to a system controller. The device includes a transformer magnetically linked with the power cable to produce a voltage signal in response to the presence of a changing current within the power cable. An input circuit located in a single housing together with the transformer is electrically connected to the transformer so as to receive the voltage signal. The input circuit produces, in response to the voltage signal, either a first signal or a first circuit condition at the output terminal of the input circuit, representative of the changing current in the power cable. A switch circuit also in the same container with the transformer has a terminal for sensing either a second signal or a second circuit condition of the remotely located system controller.

Abstract: Low threshold current switch comprising a sensing transformer, a voltage multiplier and a switch enables monitoring a very low electric current in a power cable.

Abstract: A protection device for monitoring current in a power cable to an electrical device and for controlling a remotely located starter for the electrical device in response to a system controller. The device includes a transformer magnetically linked with the power cable to produce a voltage signal in response to the presence of a changing current within the power cable. An input circuit located in a single housing together with the transformer is electrically connected to the transformer so as to receive the voltage signal. The input circuit produces, in response to the voltage signal, either a first signal or a first circuit condition at the output terminal of the input circuit, representative of the changing current in the power cable. A switch circuit also in the same container with the transformer has a terminal for sensing either a second signal or a second circuit condition of the remotely located system controller.

Abstract: A power monitoring system comprising a first current sensor suitable to sense first changing electrical current within a first conductor to a first load and a first conductor. A second conductor sensing a first voltage potential provided to the first load. A power monitor superimposes a first signal on the first conductor and first current sensor such that the first signal is sensed on the other of the first conductor and first current sensor. Associating the first voltage potential with first changing electrical current in the power usage calculation of the first load.

Abstract: An interrupt request is asserted in anticipation of a period of latency preceding preparedness of a power meter data processing device to sample a voltage or current enabling the use an interrupt to control the data processing device's performance of real-time sampling in combination with other tasks related to the power meter's operation.

Abstract: A protection device for monitoring current in a power cable to an electrical device and for controlling a remotely located starter for the electrical device in response to a system controller. The device includes a transformer magnetically linked with the power cable to produce a voltage signal in response to the presence of a changing current within the power cable. An input circuit located in a single housing together with the transformer is electrically connected to the transformer so as to receive the voltage signal. The input circuit produces, in response to the voltage signal, either a first signal or a first circuit condition at the output terminal of the input circuit, representative of the changing current in the power cable. A switch circuit also in the same container with the transformer has a terminal for sensing either a second signal or a second circuit condition of the remotely located system controller.

Abstract: A power monitoring system for electrical panels providing multi-phase power, with multiple current sensors. The disclosed power monitoring system preferably includes a support, at least four sensors defining an opening through which a wire may be extended, with the sensors being supported by the supports in a fixed spatial relationship.