Abstract: Power distribution systems and methods in which a power distribution unit (PDU) is provided with residual current monitoring at multiple outlets of an outlet module in a PDU. A residual current monitoring circuit of the PDU includes at least one current sensor associated with the outlets of the PDU to detect residual current for each of the outlets. The methods of residual current detection in a PDU having multiple power outlets includes detecting current leakage at each outlet as a difference between supplied current and return current for each outlet.

Abstract: Disclosed are power distribution systems and methods in which a power distribution unit (PDU) is provided with an overcurrent protection device and per-outlet current sensing at each of the multiple electrical outlets of the PDU. The described embodiments enable the identification of the electronic device connected to a specific outlet or electronic device that may have caused the overcurrent protection device to trip. The methods of outlet identification in a PDU having multiple electrical outlets includes detecting whether either a peak current or a half-cycle root mean square (RMS) current at each outlet has exceeded a selected threshold prior to the occurrence of the trip event associated with the overcurrent protection device.

Abstract: Methods and apparatus provide for a primary side circuit including one or more voltage nodes; and a monitoring circuit operating to monitor one or more parameters of the primary side circuit, and including at least one sensing circuit and at least one processing circuit within a secondary side circuit, where the sensing circuit includes a resistor network having an input for receiving a first sensed voltage from a first of the voltage nodes of the primary side circuit, traversing an isolation boundary between the primary side circuit and the secondary side circuit while adhering to a safety specification, which includes a primary-secondary isolation requirement, and having an output for providing a first modified sensed voltage to the processing circuit.

Abstract: Methods and apparatus provide for a primary side circuit including one or more voltage nodes; and a monitoring circuit operating to monitor one or more parameters of the primary side circuit, and including at least one sensing circuit and at least one processing circuit within a secondary side circuit, where the sensing circuit includes a resistor network having an input for receiving a first sensed voltage from a first of the voltage nodes of the primary side circuit, traversing an isolation boundary between the primary side circuit and the secondary side circuit while adhering to a safety specification, which includes a primary-secondary isolation requirement, and having an output for providing a first modified sensed voltage to the processing circuit.

Abstract: A power meter includes a voltage sensor input port configured to receive one of single phase AC voltage and three phase AC voltage values. The power meter further includes a current sensor input port configured to receive one of single phase AC current and three phase AC current values. The power meter further includes a bus connector adapted to be coupled to a data bus. The power meter further includes a module connector adapted to be coupled to a module bus. The power meter further includes a timer for producing a digitizing clock. The power meter further includes a microprocessor.

Abstract: Methods and apparatus provide for: at least one electromechanical relay including a coil and at least one pair of contacts, the contacts transitioning between a de-energized state and an energized state in response to current through the coil; a microcontroller having at least one tri-state output operating to produce ON, OFF, and FLOAT states; and a driver circuit operating, in conjunction with the tri-state output of the microcontroller, to control the current through the coil of the relay such that: (i) a transition of the tri-state output from OFF to FLOAT maintains the contacts of the relay in their de-energized state through the transition, and (ii) a transition of the tri-state output from ON to FLOAT maintains the contacts of the relay in their energized state through the transition.

Abstract: Methods and apparatus provide for a primary side circuit including one or more voltage nodes; and a monitoring circuit operating to monitor one or more parameters of the primary side circuit, and including at least one sensing circuit and at least one processing circuit within a secondary side circuit, where the sensing circuit includes a resistor network having an input for receiving a first sensed voltage from a first of the voltage nodes of the primary side circuit, traversing an isolation boundary between the primary side circuit and the secondary side circuit while adhering to a safety specification, which includes a primary-secondary isolation requirement, and having an output for providing a first modified sensed voltage to the processing circuit.

Abstract: A power meter includes a voltage sensor input port configured to receive one of single phase AC voltage and three phase AC voltage values. The power meter further includes a current sensor input port configured to receive one of single phase AC current and three phase AC current values. The power meter further includes a bus connector adapted to be coupled to a data bus. The power meter further includes a module connector adapted to be coupled to a module bus. The power meter further includes a timer for producing a digitizing clock. The power meter further includes a microprocessor.

Abstract: Methods and apparatus provide for a primary side circuit including one or more voltage nodes; and a monitoring circuit operating to monitor one or more parameters of the primary side circuit, and including at least one sensing circuit and at least one processing circuit within a secondary side circuit, where the sensing circuit includes a resistor network having an input for receiving a first sensed voltage from a first of the voltage nodes of the primary side circuit, traversing an isolation boundary between the primary side circuit and the secondary side circuit while adhering to a safety specification, which includes a primary-secondary isolation requirement, and having an output for providing a first modified sensed voltage to the processing circuit.

Abstract: Methods and apparatus provide for: measuring leakage current from a source of AC power, which provides power to at least one load circuit; and comparing the measured leakage current values against one or more predetermined thresholds to establish status therefor; and automatically performing self tests to determine whether the leakage current sensing and comparing operations are operative.

Abstract: Methods and apparatus provide for: measuring leakage current from a source of AC power, which provides power to at least one load circuit; and comparing the measured leakage current values against one or more predetermined thresholds to establish status therefor; and automatically performing self tests to determine whether the leakage current sensing and comparing operations are operative.

Abstract: Methods and apparatus provide for: measuring leakage current from a source of AC power, which provides power to at least one load circuit; and comparing the measured leakage current values against one or more predetermined thresholds to establish status therefor; and automatically performing self tests to determine whether the leakage current sensing and comparing operations are operative.

Abstract: Methods and apparatus provide for: measuring leakage current from a source of AC power, which provides power to at least one load circuit; and comparing the measured leakage current values against one or more predetermined thresholds to establish status therefor; and automatically performing self tests to determine whether the leakage current sensing and comparing operations are operative.

Abstract: Methods and apparatus provide for: at least one electromechanical relay including a coil and at least one pair of contacts, the contacts transitioning between a de-energized state and an energized state in response to current through the coil; a microcontroller having at least one tri-state output operating to produce ON, OFF, and FLOAT states; and a driver circuit operating, in conjunction with the tri-state output of the microcontroller, to control the current through. the coil of the relay such that: (i) a transition of the tri-state output from OFF to FLOAT maintains the contacts of the relay in their de-energized state through the transition, and (ii) a transition of the tri-state output from ON to FLOAT maintains the contacts of the relay in their energized state through the transition.

Abstract: Methods and apparatus provide for a primary side circuit including one or more voltage nodes; and a monitoring circuit operating to monitor one or more parameters of the primary side circuit, and including at least one sensing circuit and at least one processing circuit within a secondary side circuit, where the sensing circuit includes a resistor network having an input for receiving a first sensed voltage from a first of the voltage nodes of the primary side circuit, traversing an isolation boundary between the primary side circuit and the secondary side circuit while adhering to a safety specification, which includes a primary-secondary isolation requirement, and having an output for providing a first modified sensed voltage to the processing circuit.

Abstract: A reduced hardware complexity, reduced computational intensity finite impulse response filter architecture for filtering multiple (quadrature) channels of an RF modem comprises a cascaded arrangement of L data register stages through which respective digitally encoded data sample values of a signal to be filtered are sequentially clocked. Each data register stage has a data capacity greater than twice the code width of a respective digitized channel sample, so that each register stage can store both I and Q channel data. A multiplier unit is coupled to the data register and multiplies both I and Q contents of respective ones of the register stages by respective impulse response coefficient values. The resulting I and Q products are summed into I and Q channel convolutional sums.

Abstract: A keyboard and display terminal displays alphanumeric characters with a split screen format and with selective scrolling to display both host message information and user message information in a highly comprehensible manner. The terminal provides further message information to a user with kinetic punctuation of the message display and with audible cues. The terminal also provides automatic repertory dialing directly to a telephone line, and monitors the line for the user.The terminal can employ a display element of limited capacity, and yet provides high comprehension to an unskilled user. The terminal provides the user with both message information and operating reports for enhanced intelligibility.The terminal further sends a host a terminal-identifying code which can uniquely identify that terminal.

Abstract: A choral generator is formed from a plurality of delay channels, each including a modulated delay line which non-linearly varies the time delay imparted to a signal passing through it. The outputs of the delay channels are combined with the undelayed audio signal to form a composite output characterized by enhanced musical presence.