Adc Dsl Systems, Inc.

Square D Company

Schneider Electric Usa, Inc.

Adc Dls Systems, Inc.

Michael Baron Carter

William J Fox

Timothy B Phillips

Kevin M Jefferies

Benjamin W Edwards

Randall L Powers

Mark Kocher

Rodney B Washington

Barry Noel Rodgers

George E Burke, Jr

Roger Alan Plemmons

Dennis J Dube

George M Horne

The system and method for dynamically reducing the peak electromagnetic interference produced by a group of electrical or electronic switching devices connected to a common communications bus. The system and method includes a fixed range of frequencies that includes frequencies emitted by the group of switching devices during normal operation and subranges of frequencies within the fixed range of frequencies, each subrange of frequencies being associated with a unique bus address of one switching device in the group of switching devices. Each subrange of frequencies being determined by the unique bus address of its associated switching device and characteristic weights dynamically determined and/or assigned to its associated switching device and/or load by a microprocessor implemented algorithm.

Method for dynamically reducing peak electromagnetic interference from a group of switching devices connected on a communications bus

A method for reducing the occurrence of false ground fault detections in a central office terminal is provided. The method includes generating a no-fault signal when no ground current is detected, delaying generation of a fault signal when ground current is detected at least for the duration of an expected pulse in AC induced signal, and when the ground current persists for a sufficient period, generating a signal indicating a fault condition.

Enhanced AC immunity in ground fault detection

An improved circuit and method for decreasing the size and cost of switch mode power supplies is disclosed. In one illustrative example, a feedback circuit for a switch mode power supply is disclosed that includes two error amplifiers. The input of a first error amplifier is coupled to a voltage source associated with a load for the supply, and the input of a second error amplifier is coupled to a current source also associated with the load for the supply. Each one of the error amplifiers includes an adjustable shunt regulator that functions as an amplifier stage and diode. Also, the outputs of the shunt regulators are connected together. Therefore, the shunt regulator of the first error amplifier can be used to select a voltage limit for the power supply, the shunt regulator of the second error amplifier can be used to select a current set point for the power supply, and the open collector functions of the shunt regulators serve to OR the output signals from the two error amplifiers to produce a signal indicating the loading of the supply. In this manner, an improved feedback circuit for a switch mode power supply is provided that performs the same functions as prior feedback circuits, but has at least three less discrete components (e.g., two diodes and a voltage reference) than the prior feedback circuits. Thus, the disclosed feedback circuit significantly reduces both the size and cost of switch mode power supplies.

Circuit and method for reducing the size and cost of switch mode power supplies

Systems and methods for auto-resetting span power protection are provided. In one embodiment, a method for deactivating a protective device is provided. The method comprises determining when an overload condition occurs on a communication medium; when the overload condition occurs, deactivating at least one protective device by applying, for a first predetermined period of time, a short-circuit to an output of a power supply that provides a holding current to the at least one protective device; and after the first predetermined period of time has elapsed, removing the short-circuit on the output of the power supply.

Auto-resetting span-power protection

An improved circuit and method for increasing the stability of switch-mode power supplies via frequency fold-back is disclosed. For example, a circuit for increasing the stability of a switch-mode power supply using the compensation signal to control the frequency of the oscillator is disclosed, which includes an operational amplifier that functions to scale the compensation signal. Thus, the switching frequency of the power supply involved is decreased as the load is reduced. This novel use of the compensation signal to control the switching frequency of a switch-mode power supply significantly increases the stability of the power supply as compared to prior switch-mode power supplies. Therefore, the switch-mode power supply may be used for those applications where relatively high stability is desired.

Circuit and method for increasing the stability of switch-mode power supplies

A data error detection method for a bit, byte or word oriented network wherein a protected data unit 46 and an associated data check unit 50 are addressed to a particular field device located on the network, 10 or 26. The data check unit 50 is derived in a particular manner either solely from the protected data unit 46 or from the protected data unit 46 and particular binary codes representing attributes of the network 10 or 26 and the field device sending the protected data unit 46. The particular configuration of the checking data unit 50 is such that the receiving field device or the host 22 can perform a bit-by-bit comparison of either the received protected data unit 46 or data check unit 50 with a protected data unit 46 or data check unit 50 derived in the particular manner by the receiving host 22 or field device 14 or 18.

Data error detector for bit, byte or word oriented networks

A self-powered circuit interrupter arrangement for interrupting current in a circuit path uses a current-blocking component to ensure that an insufficient amount of accumulated power for actuating and completing interruption of the circuit path is not misused in an unwarranted attempt to interrupt the current path. The arrangement includes a current inducer circuit for providing a current signal having a magnitude corresponding to the current in the circuit path and a power supply operating from the current signal to provide a voltage signal of a predetermined value relative to common. A trip command circuit, in response to a fault detected in the circuit path, sends an electrical signal commanding that the circuit path be interrupted by using the voltage signal. The electrical signal is sent to an electrical latch located electrically in series with a coil of a solenoid mechanism. Current from the power supply passing through the coil of a solenoid mechanism causes the interruption of current in the current path. A prevention circuit is constructed and arranged to prevent the electrical signal from engaging the latch, or current from the power supply from passing through the coil until the voltage signal exceeds the predetermined value.

Growing community of inventors

Clayton, NC, United States of America

Michael Baron Carter