Plural input measuring system using electronic circuit arrangements having plural selectively energized transformer type sampling means

Claim 1

AN ELECTRONIC APPARATUS FOR SAMPLING AN ELECTRICAL D.C. CURRENT CARRYING CIRCUIT COMPRISING A HIGH INDUCTANCE TRANSFORMER HAVING A HIGH PERMEABILITY CORE AND HAVING PRIMARY AND SECONDARY WINDINGS, CONNECTIONS BETWEEN SAID ELECTRICAL CIRCUIT AND THE PRIMARY WINDING OF SAID TRANSFORMER, A RECTIFIER POLED TO PASS THE D.C. CURRENT IN SERIES WITH EACH PRIMARY WINDING, A BY-PASS CIRCUIT FOR SAID PRIMARY CIRCUIT SO ARRANGED THAT UNDER QUIESCENT CONDITIONS SUBSTANTIALLY ALL THE CURRENT IN SAID PRIMARY CIRCUIT FLOWS THROUGH THE RECTIFIER AND THE PRIMARY WINDING AND SO THAT THE CURRENT FLOWING THROUGH THE BY-PASS CIRCUIT IS NEGLIGIBLE, SAID BY-PASS CIRCUIT BEING CONNECTED ACROSS SAID PRIMARY WINDING AND RECTIFIER, MEANS FOR APPLYING AN INTERROGATING D.C. PULSE VOLTAGE ACROSS THE SECONDARY WINDING IN A DIRECTION TO TEND TO INCREASE THE EXISTING FLUX IN THE TRANSFORMER AND SUCH THAT A BACK E.M.F. IS INDUCED IN THE PRIMARY WINDING TO BACK BIAS AND CUT OFF THE RECTIFIER AND INTERRUPT THE CURRENT FLOW THROUGH THE PRIMARY OF THE TRANSFORMER, AND THEREBY TO DIVERT THE PRIMARY CURRENT THROUGH THE BY-PASS CIRCUIT, AND MEANS FOR MEASURING THE RESULTANT CURRENT FLOW THROUGH THE SECONDARY WINDING TO PROVIDE A MEASUREMENT PROPORTIONAL TO THE INTERRUPTED PRIMARY CURRENT.