Power supply circuit for a discharge lamp

A power supply circuit for a gas discharge lamp comprising:

• an inverter circuit connected to a source of direct current;
• said inverter circuit including the first and second switching transistors;
• a first transformer including a primary winding, first and second secondary windings;
• said first secondary winding, 180 degrees out of phase with said second secondary winding;
• said first and second secondary windings each including a circuit connection to said first and second switching transistors, respectively;
• a resonant element consisting of an inductor and a capacitor connected in series between said lamp and said inverter circuit;
• means to ensure said first transformer senses a zero crossing of current comprising a pair of oppositely poled diodes connected in parallel with said primary winding of said first transformer;
• a second transformer connected in parallel with said resonant element capacitor;
• said second transformer including at least two primary windings;
• whereby said second transformer operates to limit the voltage of said power supply to a predetermined level.