At&t Bell Laboratories

Lucent Technologies Inc.

Richard H Hock

Jeffrey John Boylan

Allen Frank Rozman

Kenneth J Timm

For use in a distributed power system having first and second power processing modules, a power processing module for, and method of synchronizing an operation of the second power processing module with the first power processing module and a power converter employing the power processing module or the method. In one embodiment, the power processing module includes: (1) a synchronization input terminal adapted to receive a first control signal, (2) a free-running oscillator that generates a gate drive signal for controlling a switch of the power processing module, the gate drive signal having a frequency that is a free-running frequency of the power processing module, (3) a synchronization circuit, coupled to the synchronization input terminal and the free-running oscillator, that synchronizes the gate drive signal with the first control signal and (4) a frequency setting circuit, coupled to the synchronization input terminal and the free-running oscillator, that modifies an operation of the free-running oscillator.

System and method for synchronizing and interleaving power modules

A voltage control circuit comprises a transformer (18) having primary (17) and secondary (20, 21) windings, an input coupled to said primary winding, first and second switch devices (11, 12) each coupled to said primary winding of the transformer, and a clamping capacitor (28) coupled to the transformer and at least one of the first and second switches. An output filter (25, 26) is coupled through a rectifier (23, 24) to the secondary winding of the transformer and an output is taken from the output filter. Means comprising a feedback circuit (13, 14, 15) coupled on one side to the output filter and on the other side to control terminals of the first and second switches cause the first and second switches to conduct current alternately. Operation of the circuit is stabilized by including an interconnection (29) of the clamping capacitor to the feedback circuit for generating a signal that modifies the energy applied by the feedback circuit to the control terminals of the first (11) and second (12) switches.

Clamped mode DC-DC converter

A current converter circuit that supplies send and return currents to a balanced transmission line includes current sensing circuitry that responds to a current unbalance or a differential current, independently of longitudinal currents in the balanced line. A reference voltage and two inputs to a comparator monitor the voltage drop across a voltage divider connecting the send and return leads of the transmission line. The voltage divider has a grounded center tap so that longitudinal currents flow to ground and provide equal and opposite polarity voltages across the divider, which cancel each other. Unbalanced currents provide a corresponding differential voltage input to the comparator, whose control voltage output is utilized to initiate corrective action in a current control circuit.

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Garland, TX, United States of America

Richard H Hock