Diode rectifier with overvoltage protection

Claim 1

APPARATUS FOR SUPPLYING AN INDUCTIVE LOAD WITH UNIDIRECTIONAL CURRENT FROM AN ALTERNATING CURRENT SOURCE COMPRISING, IN COMBINATION: A RECTIFIER COMPRISING A BRIDGE OF SILICON DIODES, SAID BRIDGE HAVING INPUT AND OUTPUT TERMINALS, THE INPUT TERMINALS BEING ADAPTED TO BE CONNECTED ACROSS AN ALTERNATING VOLTAGE SOURCE TO PRODUCE A UNIDIRECTIONAL VOLTAGE AT THE OUTPUT TERMINALS OF THE RECTIFIER; CIRCUIT MEANS BETWEEN SAID OUTPUT TERMINALS AND SAID LOAD FOR DELIVERING THE VOLTAGE PRODUCED AT SAID OUTPUT TERMINALS TO SAID LOAD, SAID CIRCUIT MEANS INCLUDING A SWITCH AND A CAPACITOR CONNECTED ACROSS THE SWITCH, SAID CAPACITOR SERVING TO SUPPRESS THE ARC WHICH OTHERWISE WOULD BE PRODUCED AT THE SWITCH TERMINALS BY THE INDUCED VOLTAGE GENERATED BY THE INDUCTIVE LOAD WHEN THE SWITCH IS OPENED; AND CURRENT CONDUCTING MEANS FOR MINIMIZING THE INVERSE VOLTAGE IMPRESSED ON THE DIODES WHEN THE SWITCH IS OPENED, SAID CURRENT CONDUCTING MEANS INCLUDING AT LEAST ONE GAS DISCHARGE TUBE CONNECTED IN THE CIRCUIT MEANS IN PARALLEL WITH THE RECTIFIER AND HAVING THE CHARACTERISTIC THAT IT DOES NOT CONDUCT WHEN ONLY THE MAXIMUM OUTPUT VOLTAGE OF THE RECTIFIER IS PRESENT ACROSS THE CONDUCTING MEANS WHILE THE SWITCH IS CLOSED, BUT BECOMES CONDUCTIVE WHEN VOLTAGE SPIKES ARE PRESENT ACROSS THE CONDUCTING MEANS IMMEDIATELY AFTER THE SWITCH IS OPENED.