Temperature control system for a diffusion furnace

Claim 1

IN A DIFFUSION FURNACE, MEANS FORMING AT LEAST ONE ZONE, HEATING MEANS DISPOSED IN THE ZONE, A SOURCE OF POWER, A TRANSFORMER CONNECTED TO THE SOURCE OF POWER SATURABLE CORE REACTOR CONNECTED TO THE SOURCE OF POWER AND TO THE TRANSFORMER FOR CONTROLLING THE POWER SUPPLIED TO THE TRANSFORMER, TEMPERATURE SENSING MEANS DISPOSED IN SAID ZONE, MEANS PROVIDING A PREDETERMINED SET POINT TEMPERATURE CONNECTED TO SAID TEMPERATURE SENSING MEANS FOR PROVIDING A SIGNAL PROPORTIONAL TO THE DIFFERENCE BETWEEN THE MASURED TEMPERATURE AND THE SET POINT TEMPERATURE A GALVANOMETER CONNECTED TO SAID TEMPERATURE SENSING MEANS AND SAID MEANS PROVIDING A SET POINT TEMPERATURE, A RESISTIVE NETWORK AND MEANS INCLUDING A MAGNETIC AMPLIFIER CONNECTING SAID RESISTIVE NETWORK TO SAID SATURABLE CORE REACTOR, SAID RESISTIVE NETWORK PROVIDING A CONSTANT OUTPUT IMPEDANCE FOR SAID GALVANOMETER AND IN ADDITION PROVIDING MEANS FOR REGULATING THE SIGNAL FROM SAID GALVANOMETER FROM ZERO THROUGH 100 PERCENT.