In-phase current detection

Claim 1

A NETWORK FOR MEASURING THE IN-PHASE CURRENT IN A POLYPHASE ALTERNATING CURRENT TRANSMISSION NETWORK SUPPLYING A LAGGING POWER FACTOR LOAD COMPRISING A CURRENT TRANSFORMER HAVING A PRIMARY WINDING IN ONE LINE OF SAID NETWORK AND A SECONDARY WINDING HAVING A RESISTANCE LOAD THEREACROSS WHEREBY THE VOLTAGE ACROSS SAID RESISTANCE IS A MEASURE OF THE TOTAL CURRENT IN SAID LINE, A VOLTAGE TRANSFORMER HAVING A PRIMARY WINDING CONNECTED ACROSS SAID ONE LINE AND ANOTHER LINE OF SAID NETWORK, AND A CENTERTAPPED SECONDARY WINDING, SAID SECONDARY WINDING SUPPLYING A FIRST CURRENT LOOP COMPRISING A CAPACITANCE AND A POTENTIOMETER HAVING ONE END OF ITS RESISTANCE PORTION CONNECTED TO SAID CENTER TAP AND A SECOND CURRENT LOOP COMPRISING A RESISTANCE AND SAID POTENTIOMETER, SAID RESISTANCE AND SAID CAPACITANCE BEING SELECTABLE TO PROVIDE A PREDETERMINED PHASE SHIFT IN THE CURRENT THROUGH SAID POTENTIOMETER WITH RESPECT TO THE VOLTAGE INDUCED IN SAID VOLTAGE TRANSFORMER SECONDARY WINDING TO PROVIDE A CURRENT IN PHASE OPPOSITION TO THE VOLTAGE COMPONENT IN SAID RESISTANCE LOAD DUE TO REACTIVE CURRENT IN SAID LINE, THE CONTACT ARM OF SAID POTENTIOMETER BEING SET TO PRODUCE A VOLTAGE BETWEEN SAID ARM AND SAID CENTER TAP EQUAL IN MAGNITUDE TO THE REACTIVE COMPONENT OF THE VOLTAGE IN SAID RESISTANCE LOAD, MEANS FOR CONNECTING THE VOLTAGES IN SERIES AND RECTIFYING THE RESULTANT TO PRODUCE A UNIDIRECTIONAL SIGNAL PROPORTIONAL TO THE IN-PHASE CURRENT IN SAID ONE LINE.