Apparatus including a bucking transformer for operating electric discharge lamps

Claim 1

A BALLAST APPARATUS COMPRISING A PAIR OF INPUT LEADS FOR CONNECTION IN CIRCUIT WITH AN ALTERNATING POWER SOURCE, OUTPUT LEADS FOR CONNECTION IN CIRCUIT WITH AT LEAST ONE ELECTRIC DISCHARGE LAMP, A BUCKING TRANSFORMER HAVING A CENTER TAPPED PRIMARY WINDING AND A SECONDARY WINDING, A CURRENT TRANSFORMER HAVING A PRIMARY WINDING AND A CENTER TAPPED SECONDARY WINDING, SAID SECONDARY WINDING OF SAID BUCKING TRANSFORMER AND SAID PRIMARY WINDING OF SAID CURRENT TRANSFOMER BEING CONNECTED IN CIRCUIT WITH ONE OF SAID OUTPUT LEADS AND ONE OF SAID INPUT TERMINAL LEADS FOR CONNECTION IN SERIES CIRCUIT RELATION WITH SAID LAMP, A FULL WAVE BRIDGE RECTIFIER HAVING INPUT TERMINALS AND OUTPUT TERMINALS, SAID INPUT TERMINALS BEING CONNECTED IN CIRCUIT WITH SAID INPUT TERMINAL LEADS FOR CONNECTION WITH THE ALTERNATING POWER SOURCE, A PAIR OF TRANSISTORS, EACH OF SAID TRANSISTORS HAVING A COLLECTOR, AN EMITTER, AND A BASE ELECTRODE, ONE OF SAID OUTPUT TERMINALS OF SAID BRIDGE RECTIFIER BEING CONNECTED IN CIRCUIT WITH THE TAP OF THE PRIMARY WINDING OF SAID BUCKING TRANSFORMER, THE OTHER OF SAID TERMINALS BEING CONNECTED IN CIRCUIT WITH THE EMITTER ELECTRODES OF SAID TRANSISTORS AND THE TAP OF SAID SECONDARY WINDING OF THE CURRENT TRANSFORMER, CIRCUIT MEANS CONNECTING THE ENDS OF THE PRIMARY WINDING OF SAID BUCKING TRANSFORMER IN CIRCUIT WITH THE COLLECTOR ELECTRODES OF SAID TRANSISTORS AND CONNECTING THE ENDS OF THE SECONDARY WINDING OF SAID CURRENT TRANSFOMER IN CIRCUIT WITH THE BASE ELECTRODES OF SAID TRANSISTORS, SAID TRANSISTORS PROVIDING A VARIABLE IMPEDANCE IN THE PRIMARY CIRCUIT OF SAID BUCKING TRANSFORMER TO REGULATE THE CURRENT FLOW THROUGH THE SECONDARY WINDING OF THE BUCKING TRANSFORMER IN RESPONSE TO CHANGES IN THE CURRENT SUPPLIED AT THE OUTPUT LEADS.