Apparatus for detecting a short circuit across a gap by comparing the gap voltage with a delayed portion thereof

Abstract

Abstract A METHOD AND APPARATUS FOR DETECTING A SHORT CIRCUIT ACROSS A GAP BY DETECTING THE VOLTAGE ACROSS THE GAP AND COMBINING THAT VOLTAGE WITH A SECOND VOLTAGE PRODUCED BY DELAYING THE GAP VOLTAGE SO THAT ONLY A SHORT CIRCUIT WILL PRODUCE A SIGNAL SUFFICIENT TO INDICATE A SHORT CIRCUIT CONDITION. MORE PARTICULARLY THE INVENTION IS INTENDED FOR USE WITH APPARATUS FOR THE ELECTROCHEMICAL REMOVAL OF MATERIAL WHEREBY A WORKPIECE, USUALLY CONNECTED AS AN ANODE, AND A TOOL, USUALLY CONNECTED AS A CATHODE, FORM A GAP WHICH IS CONTINUOUSLY FILLED WITH A FLOWING ELCTRO- LYTE SOLUTION SO THAT AS DIRECT CURRENT FLOWS THROUGH THE ELECTROLYTE AND ACROSS THE GAP, MATERIAL WILL BE REMOVED FROM THE ANODE. SHUNTING DEVICES SUCH AS THYRISTORS ARE PREFERABLY CONNECTED IN PARALLEL ACROSS THE GAP SO THAT WHEN THE COMBINATION OF THE GAP VOLTAGE AND A SECOND VOLTAGE PRODUCED BY DELAYING THE GAP VOLTAGE INDICATES A SHORT CIRCUIT CONDITION, THESE SHUNTING DEVICES CAN DISSIPATE THE ENERGY RESULTING FROM THE SHORT CIRCUIT CONDITION AND PREVENT THE OVERFLOW OF CURRENT ACROSS THE GAP.

Inventors

• 👤 H Kohler

Bibliographic Details