Patent ID: 7012823

Claim:
A control system comprising: a firing control circuit outputting a plurality of firing commands; a plurality of rectifier bridges, each of said rectifier bridges adapted to convert a plurality of alternating current voltages of a plurality of alternating current phases to a voltage, each of said rectifier bridges comprising a plurality of segments, each of said segments having an element, each of the elements of one of said rectifier bridges being electrically interconnected in parallel with at least one corresponding element of at least another one of said rectifier bridges; a plurality of conduction monitors for each of said rectifier bridges, each of said conduction monitors adapted to sense conduction or non-conduction of a corresponding one of said elements; a bridge control circuit for each of said rectifier bridges, each of said bridge control circuits adapted to input a corresponding one of the firing commands, to output a plurality of control signals responsive to said corresponding one of the firing commands in order to repetitively fire at least some of said elements of a corresponding one of said rectifier bridges, and to input the sensed conduction or non-conduction of corresponding ones of said elements of the corresponding one of said rectifier bridges; and a communication channel adapted to communicate the sensed conduction or non-conduction of the elements of said rectifier bridges from said bridge control circuits to said firing control circuit, and to communicate the firing commands from said firing control circuit to said bridge control circuits, wherein said firing control circuit includes a routine adapted to determine, for the elements of said rectifier bridges, if any of said elements of one of said rectifier bridges and all of said at least one corresponding element of at least another one of said rectifier bridges, which are electrically interconnected in parallel, have the sensed non-conduction and to responsively output a signal.