Ballast apparatus having a portion tuned to a harmonic frequency

Claim 1

IN COMBINATION WITH LOW PRESSURE GASEOUS DISCHARGE APPARATUS HAVING NEGATIVE RESISTANCE CHARACTERISTICS, A DEVICE FOR OPERATING SAID APPARATUS FROM A SOURCE OF SUBSTANTIALLY SINUSOIDAL ALTERNATING VOLTAGE OF A GIVEN FREQUENCY, SAID DEVICE HAVING AN INPUT CIRCUIT ADAPTED TO BE CONNECTED TO SAID SOURCE AND AN OUTPUT CIRCUIT ADAPTED TO BE CONNECTED TO SAID APPARATUS, SAID DEVICE COMPRISING A TRANSFORMER AND MEANS FOR ACCENTUATING IN SAID TRANSFORMER AN ODD HARMONIC ABOVE THE THIRD TO AN EXTEND OVER ALL THE OTHER HARMONICS OF SAID FREQUENCY SO THAT THE HARMONIC OF MAXIMUM ACCENTUATION IS AN ODD HARMONIC ABOVE THE THIRD, SAID MEANS FOR ACCENTUATING SAID HARMONIC COMPRISING A CONDENSER AND INDUCTIVE MEANS IN CIRCUIT WITH ONE ANOTHER, THE INDUCTIVE MEANS BEING AT LEAST A PART OF SAID TRANSFORMER, SAID TRANSFORMER INCLUDING AN IRON CORE HAVING A HIGH RELUCTANCE GAP WITH A SATURATING MAGNETIC BRIDGE THEREACROSS WITH THE BRIDGE LOCATED IN THE MAGNETIC CIRCUIT OF THE INDUCTIVE MEANS, SAID CONDENSER AND INDUCTIVE MEANS BEING SUBSTANTIALLY TUNED TO SAID HARMONIC, AND A REACTOR IN SERIES WITH THE CONDENSER AND CARRYING SUBSTANTIALLY NONE OF THE CURRENT FLOWING THROUGH THE OUTPUT CIRCUIT DURING NORMAL OPERATION OF THE DISCHARGE APPARATUS.