Protective circuitry and indicating means for rectifier systems

Claim 1

IN COMBINATION WITH A RECTIFIER LEG HAVING A PLURALITY OF RECTIFIER CELLS CONNCETED IN SERIES, MEANS FOR DETECTING THE FAILURE OF AT LEAST ONE OF SAID RECTIFIER CELLS COMPRISING: A TRANSFORMER HAVING A PRIMARY WINDING CONNECTED ACROSS SAID RECTIFIER LEG AND A PLURALITY OF SECONDARY WINDINGS, SAID SECONDARY WINDINGS EACH BEING CONNECTED ACROSS A CORRESPONDING RECTIFIER CELL; A BLOCKING RECTIFIER IN SERIES WITH EACH OF SAID SECONDARY WINDINGS; IMPEDANCE MEANS AND IMPEDANCE MEANS INCLUDING AN INDICATING DEVICE CONNECTED IN SERIES WITH SAID PRIMARY WINDING TO FORM A SERIES CIRCUIT ACROSS SAID RECTIFIER LEG, SAID SERIES CIRCUIT PROVIDING VOLTAGE DROPS ACROSS SAID PRIMARY WINDING AND SAID INDICATING MEANS HAVING A PREDETERMINED RATIO DURING NORMAL OPERATION OF THE RECTIFIER LEG; EACH OF SAID SECONDARY WINDINGS BEING RESPONSIVE TO THE FAILURE OF A RECTIFIER CELL FOR CHANGING THE RATIO OF THE VOLTAGE DROPS ACROSS AND SAID PRIMARY WINDING AND SAID INDICATING MEANS TO ACTIVATE SAID INDICATING MEANS.