Ballast circuit with a japped transformer flyback converter providing driving energy for start, glow and run modes of a lamp

A circuit arrangement for generating start, glow and run signals to be applied to and for operating a DC arc discharge lamp in a start, glow, and run modes, the circuit arrangement comprising:

• a) a tapped transformer flyback converter circuit for providing the driving energy for operating the lamp during the start, glow and run modes;
• b) said tapped transformer flyback converter circuit including:
• i) a tapped point;
• ii) a primary winding for providing driving energy for operating the lamp during the run and glow modes;
• said primary winding having a first end coupled to a first end of said lamp and a second end connected to said tapped point;
• and
• iii) a secondary winding for driving the lamp during the start mode;
• said secondary winding having a first end coupled to said tapped point and a second end coupled to a second end of said lamp;
• iv) said second end of said primary winding being coupled to a second end of said lamp substantially other than through said secondary winding during the run and glow modes;
• said second end of said primary winding being coupled through said secondary winding to said second end of said lamp by a circuit including a resistance;
• the value of said resistance being sufficiently high so as to reduce power loss in said resistance to a tolerable level during the run mode;
• c) blocking means for providing a blocking function for a glow circuit during the start mode;
• d) a switching device serially coupled to said tapped point and being effective to control energy transferred through said tapped transformer flyback converter circuit;
• and
• e) an inductor member coupled in a common manner between the output of said glow circuit and a run circuit on one end and said discharge lamp on the opposite end thereof such that said inductor member develops sufficient voltage so as to operate said discharge lamp in said glow and run modes without the need of further inductive elements and said tapped transformer flyback circuit functions during said start mode without need of further inductive elements.