High power process control apparatus

Claim 1

INDUSTRIAL PROCESS CONTROL APPARATUS FOR REGULATING THE FLOW OF LARGE AMOUNTS OF ELECTRICAL ENERGY SO AS TO MAINTAIN A VARIABLE OF THE PROCESS AT A DESIRED VALUE, SAID APPARATUS COMPRISING, IN COMBINATION, MEANS FOR DEVELOPING A MEASUREMENT SIGNAL CORRESPONDING TO THE VALUE OF THE PROCESS VARIABLE; SET SIGNAL MEANS; COMPARISON CIRCUIT MEANS RESPONSIVE TO SAID MEASUREMENT AND SET SIGNAL TO PRODUCE A DEVIATION SIGNAL CORRESPONDING TO THE DIFFERENCE BETWEEN SAID PROCESS VARIABLE AND SAID DESIRED VALUE; AT LEAST ONE BALANCED MAGNETIC AMPLIFIER ADPATED TO PRODUCE NO OUTPUT SIGNAL WHEN IT RECEIVES NO INPUT SIGNAL AND TO BECOME UNBALANCED AND PRODUCE AN OUTPUT SIGNAL IN RESPONSE TO ITS RECEIPT OF AN INPUT SIGNAL, SAID BALANCED MAGNETIC AMPLIFIER BEING CONNECTED TO THE OUTPUT OF SAID COMPARISON CIRCUIT MEANS FOR AMPLIFYING SAID DEVIATION SIGNAL; CONTROL SIGNAL GENERATING MEANS RESPONSIVE TO THE OUTPUT OF SAID BALANCED MAGNETIC AMPLIFIER; CONTROLLED RECTIFIER MEANS; A LOAD AND AN ALTERNATING-CURRENT ELECTRICAL POWER SOURCE CONNECTED TOGETHER AND TO SAID CONTROLLED RECTIFIER MEANS, SAID CONTROL SIGNAL GENERATING MEANS BEING OPERABLE TO GAGE AND CONTROLLED RECTIFIER MEANS ON FOR A PORTION OF THE ALTERNATING-CURRENT CYCLE CORRESPONDING TO THE MAGNITUDE OF THE OUTPUT OF SAID BALANCED MAGNETIC AMPLIFER; AND FEEDBACK MEANS CONNECTED BETWEEN SAID LOAD AND THE INPUT OF SAID BALANCED MAGNETIC AMPLIFIER, SAID FEEDBACK MEANS INCLUDING RECTIFIER MEANS FOR PRODUCING A D.-C. FEEDBACK SIGNAL SAID FEEDBACK CIRCUIT FURTHER INCLUDING REACTIVE MEANS FOR ALTERING SAID D.-C. FEEDBACK SIGNAL TO INTRODUCE TIME-VARYING ACTION IN THE OUTPUT CURRENT FLOWING THROUGH SAID LOAD, THE CONDUCTION OF SAID CONTROLLED RECTIFER MEANS BEING AUTOMATICALLY REGULATED BY SAID CONTROL SIGNAL GENERATING MEANS IN RESPONSE TO SAID DEVIATION SIGNAL AND SAID FEEDBACK SIGNAL, TO MAINTAIN SAID PROCESS VARIABLE STABLY AT SAID DESIRED VALUE.