Abstract: A power management system includes a plurality of monitors, communicatively coupled together over a communications medium. Each respective monitor of the plurality of monitors is configured to capture power factor (PF) data at a corresponding distribution segment for calculation of a PF correction.

Abstract: Apparatuses and methods to reduce safety risks associated with photovoltaic systems by providing a safety switch on a photovoltaic panel. In one embodiment, a photovoltaic panel includes: at least one photovoltaic cell; a connector to output energy from the photovoltaic panel; and a switch coupled between the at least one photovoltaic cell and the connector. The switch is configured to disconnect the at least one photovoltaic cell from the connector during installation of the photovoltaic panel, and to connect the at least one photovoltaic cell with the connector after installation of the photovoltaic panel.

Abstract: A solar cell having an open loop voltage that approaches a critical voltage range when exposed to light. A circuit, connected to the solar cell, is configured to load the solar cell when the open loop voltage of the solar cell reaches a threshold within a predetermined range of the critical voltage range.

Abstract: Systems and methods are disclosed for removing charge buildup/leakage from solar modules. A discharge controller may be coupled between a solar module and a string bus of a solar array. The discharge controller may be configured to disconnect the solar module from the string bus, and to connect a grounded frame to solar cells of the solar module. Since the grounded frame of the solar module may be grounded, connecting the grounded frame and the solar cells allows charge buildup/leakage to discharge into ground.

Abstract: Systems and methods are disclosed for automatically or remotely rendering a solar array safe during an emergency or maintenance. A watchdog unit is disclosed for monitoring a signal from a central controller. If the signal is lost, interrupted, or becomes irregular, or if a shutdown signal is received, then the watchdog unit can shutdown one or more solar modules. Shutting down a solar module can mean disconnecting it from a power bus of the solar array or lowering the solar module voltage to a safe level.

Abstract: Systems and methods to balance currents among a plurality of photovoltaic units connected in series. In aspect, a management unit is coupled between a photovoltaic energy production unit and a string of energy production units. The management unit has an energy storage element (e.g., a capacitor) connected to the photovoltaic energy production unit. The management unit further has a switch to selectively couple to the energy storage element and the photovoltaic energy production unit to the string. The management unit allows the current in the string to be larger than the current in the photovoltaic energy production unit.

Abstract: Apparatuses and methods include a photovoltaic energy production unit to generate electricity. A local management unit is coupled between the photovoltaic energy production unit and a connection of energy production units forming a string bus. The local management unit includes a controller and switching circuitry. The controller provide a control for the switching circuitry to deliver electrical energy to the string bus. A communication transmission modulator is associated with the local management unit. The communication transmission modulator modulates the control with data to be transmitted from the local management unit over the string bus.

Abstract: Methods and systems with a step-up converter are provided based on a boost converter. In one aspect, a step-up converter includes: a boost converter having a first inductor; a second inductor paired on a core with the first inductor; and a rectifier circuit coupled with the second inductor to generate a direct current output.

Abstract: High voltage direct current systems to connect direct current energy sources to an alternating current system. In one aspect, a system includes a plurality of direct current modules having variable direct current inputs; an inverter; and a direct current bus to connect the direct current modules to the inverter, where the bus is configured to operate at a nominal voltage higher than 100 volts and to operate within 10 percent of the nominal operating voltage.

Abstract: Systems and methods to balance currents among a plurality of photovoltaic units connected in series. In aspect, a management unit is coupled between a photovoltaic energy production unit and a string of energy production units. The management unit has an energy storage element (e.g., a capacitor) connected to the photovoltaic energy production unit. The management unit further has a switch to selectively couple to the energy storage element and the photovoltaic energy production unit to the string. The management unit allows the current in the string to be larger than the current in the photovoltaic energy production unit.

Abstract: Apparatuses and methods to reduce safety risks associated with photovoltaic systems by providing a safety switch on a photovoltaic panel. In one embodiment, a photovoltaic panel includes: at least one photovoltaic cell; a connector to output energy from the photovoltaic panel; and a switch coupled between the at least one photovoltaic cell and the connector. The switch is configured to disconnect the at least one photovoltaic cell from the connector during installation of the photovoltaic panel, and to connect the at least one photovoltaic cell with the connector after installation of the photovoltaic panel.

Abstract: In a wireless communication system in which a base station communicates with plural mobile stations using frames of digital data, each frame having a control slot and plural voice (or data) slots, the present invention divides at least some of the slots into two portions and receives communications from one of the mobile stations during a first portion of a voice slot and communicates with the same mobile station during the second portion of the same slot.

Abstract: In a wireless communication system in which a base station communicates with plural mobile stations using a control channel and plural voice (or data) channels, the present invention uses the control channel as a voice channel whenever the other voice channels are in use and a request is received from a mobile station for another voice channel. The base station's use of the control channel varies as the control channel switches from a control channel to a voice channel and back to a control channel again.

Abstract: In a wireless communication system in which plural base stations communicate with plural mobile stations using a control slot and plural voice (or data) slots, the present invention dynamically allocates which of a predetermined set of frequencies are used by a given base station at a given time. The base stations monitor the predetermined set of frequencies to determine which frequencies are being used within which slots within the range of radio reception of the base station. Currently unused frequency/slot combinations are assigned by a base station to service the next request for a voice slot.

Abstract: A digital communication system, which may be a Time Domain Multiple Access system, is operated with plural antenna to reduce the problems associated with fading, interference and multipath in signals received from mobile, wireless units. The protocol used between the fixed station and the mobile, wireless units provides an opportunity for the fixed station to evaluate the signal received from the wireless unit and to transmit to the wireless unit using the antenna judged to have the best received signal.

Abstract: A system and method for readily varying the configuration of a telephone system and the functions/features available to the users of wireless telephone instruments on the system. The telephone instruments may include a display which can be configured by interaction with a base station to vary the interpretation given to inputs received from the user. Features available to the user of a particular telephone instrument may be specifically adapted to the user and may be readily modified as the user changes, as the user's authorization changes, and/or as the telephone system's capabilities are changed.

Abstract: A wireless PBX system utilizes base stations dispersed throughout an area to be served with wireless telephone service. The base stations utilize multiple antennae to reduce problems associated with fading and multipath. In the present invention, the antennae of a base station or similar apparatus are rotatable, at least in pairs, so that the base station may be hung vertically, horizontally, or at some other angle to the horizon and the antennae may be readily oriented to a position which provides for preferred propagation characteristics for the antennae for the local area in which the base station is mounted.

Abstract: A method and apparatus for determining the timing of symbols within a multiple symbol telecommunicated message by evaluating signal characteristics in both the preamble and data portions of a message. Samples of a received signal are taken at a periodic basis and a predetermined characteristic of the signal is evaluated for each sample. The sum of every ith sample may be evaluated to determine the symbol framing within the message.

Abstract: System and method for operating a wireless telephone system particularly a wireless Private Branch Exchange (PBX), as both a voice system and a pager system. The system includes a protocol for communicating both voice conversations and display data to a remote unit. Remote units, which may be pagers, personal communications units, mobile telephones, and the like, communicate with the wired portion of the system using the same protocols and signalling techniques.

Abstract: A method and apparatus for reducing power consumed by mobile wireless units, such as personal communications systems or wireless PBX telephones, by reducing the frequency with which various circuits within the units are fully energized. During on-going voice communications between a base station and a wireless unit, the wireless unit reduces the frequency of its references to a control channel and may eliminate such references altogether. In addition, while idle, the wireless units may not attempt to reference the control channel during all occurrences of the control channel, reducing both power consumption and the possibility of collisions with other wireless units in attempting to access the control channel.