Control system for electrical precipitators

Claim 1

AN ELECTRICAL PRECIPITATOR SYSTEM COMPRISING A TRANSFORMER SUPPLIED FROM AN ALTERNATING CURRENT SUPPLY SOURCE, RECTIFYING MEANS FOR THE OUTPUT OF SAID TRANSFORMER, A DISCHARGE ELECTRODE CONNECTED TO SAID RECTIFYING MEANS, AN ELECTRICAL ENERGY CONTROL SYSTEM FOR CONTROLLING THE FLOW OF CURRENT AND VOLTAGE TO THE DISCHARGE ELECTRODE COMPRISING MEANS FOR SENSING THE FLOW OF CURRENT TO SAID PRECIPITATOR, SATURABLE REACTOR MEANS CONNECTED BETWEEN SAID SOURCE ND SAID TRANSFORMER, A CURRENT CONTROL CIRCUIT CONNECTED TO SAID SENSING MEANS AND SAID SATURABLE REACTOR INCLUDING MEANS FOR DEVELOPING A SIGNAL CORRESPONDING TO THE ACTUAL CURRENT FLOW TO SAID DISCHARGE ELECTRODE, MEANS FOR DEVELOPING A REFERENCE SIGNAL CORRESPONDING TO A PRESELECTED CONSTANT LEVEL CURRENT FLOW, MEANS FOR GENERATING A SIGNAL CORRESPONDING TO THE DIFFERENCE BETWEEN SAID ACTUAL AND PRESELECTED CONSTANT LEVEL SOLELY WHEN SAID ACTUAL CURRENT FLOW EXCEEDS SAID PRESELECTED LEVEL OF CURRENT FLOW SO AS TO VARY THE IMPEDANCE OF SAID SATURABLE REACTOR MEANS AND REDUCE SAID CURRENT FLOW TO SAID DISCHARGE ELECTRODES TO SAID PRESELECTED VALUE, A VOLTAGE CONTROL CIRCUIT CONNECTED TO SAID SENSING MEANS AND SAID SATURABLE REACTOR MEANS INCLUDING MEANS BEING INOPERATIVE DURING NORMAL CURRENT FLOW AND BEING OPERATIVE ONLY UPON THE OCCURRENCE OF TRANSIENT CURRENT SURGES RESULTING FROM SPARK-OVER FOR DEVELOPING A PULSE SIGNAL, A VOLTAGE REGULATING CIRCUIT INCLUDING MEANS FOR SELECTIVELY ADJUSTING THE MAGNITUDE AND THE RATE OF THE PULSE SO AS TO VARY THE IMPEDANCE OF SAID SATURABLE REACTOR MEANS AND REDUCE SAID VOLTAGE TO SAID DISCHARGE ELECTRODE IN ACCORDANCE WITH A PREDETERMINED SPARK RATE.