Uni-directional current supply and measuring means

Claim 1

A VARIABLE DIRECT CURRENT SOURCE COMPRISING, MEANS FOR SUPPLYING DIRECT CURRENT POWER, AN OUTPUT CIRCUIT HAVING OUTPUT TERMINALS ACROSS WHICH AN ELECTRICAL LOAD IS CONNECTED FOR RECEIVING A PRESELECTED LOAD CURRENT SUPPLIED BY THE VARIABLE DIRECT CURRENT SOURCE, FIRST STANDARD RESISTOR MEANS OF A SELECTED FIXED RESISTANCE CONNECTED IN SERIES WITH SAID OUTPUT CIRCUIT, SECOND RESISTANCE MEANS OF SELECTED FIXED RESISTANCE, RHEOSTAT MEANS CONNECTED IN SERIES WITH SAID SECOND STANDARD RESISTOR MEANS TO FORM A CURRENT CONDUCTING RESISTANCE BRANCH, SAID RESISTANCE BRANCH BEING CONNECTED TO BRIDGE SAID FIRST STANDARD RESISTANCE MEANS, TO RELATIVE VALUES OF RESISTANCE OFF SAID FIRST RESISTOR MEANS WITH RESPECT TO THE RESISTANCE OF SAID BRANCH BEING SELECTED TO RESULT IN A SUBSTANTIAL PORTION OF THE LOAD CURRENT TO FLOW THROUGH SAID FIRST STANDARD RESISTOR MEANS, WHEREAS THE BALANCE OF THE LOAD CURRENT BRANCHES OFF INTO SAID RESISTANCE BRANCH, A DIRECT CURRENT REFERENCE OF FIXED PRESET VOLTAGE, MEANS FOR COMPARING THE VOLTAGE POTENTIAL ACROSS SAID SECOND RESISTOR MEANS AGAINST SAID REFERENCE VOLTAGE FOR MAINTAINING A PRESELECTED VOLTAGE POTENTIAL ACROSS SAID SECOND RESISTOR MEANS AND ALSO FOR PROVIDING AN ERROR SIGNAL WHEN THE COMPARED VOLTAGES ARE NOT IN BALANCE, AND MEANS IN SAID OUTPUT CIRCUIT FOR REGULATING THE VALUE OF SAID LOAD CURRENT IN RESPONSE TO SAID ERROR SIGNAL TO MAINTAIN VOLTAGE BALANCE, WHEREBY THE PRESELECTED VALUE OF LOAD CURRENT IS A FUNCTION OF THE PRESET VALUE OF RESISTANCE SELECTED FOR SAID RHEOSTAT MEANS.