Abstract: Methods and apparatus for controlling a high intensity discharge lamp and a power supply system for the high intensity discharge lamp are disclosed. The system relates to a method for controlling high intensity discharge lamp comprising supplying a signal of variable frequency and constant filling factor from a switches cascade to a ballast circuit and the lamp, said ballast circuit having at least one condenser and at least one inductance. The method uses the signal of periodically fluctuating frequency and constant filling factor of 50%, supplied from the electronic switches cascade of the half-bridge type, connected with the ballast circuit and the lamp, where the ballast circuit includes at least first condenser, the lamp and includes first inductance and second condenser forming a resonant circuit. A supply system for high intensity discharge lamp is also disclosed.

Abstract: Methods and apparatus for controlling a high intensity discharge lamp and a power supply system for the high intensity discharge lamp are disclosed. The system relates to a method for controlling high intensity discharge lamp comprising supplying a signal of variable frequency and constant filling factor from a switches cascade to a ballast circuit and the lamp, said ballast circuit having at least one condenser and at least one inductance. The method uses the signal of periodically fluctuating frequency and constant filling factor 50 to 50%, supplied from the electronic switches cascade of the half-bridge type, connected with the ballast circuit and the lamp, where the ballast circuit includes at least first condenser, the lamp and includes first inductance and second condenser forming a resonant circuit. A supply system for high intensity discharge lamp is also disclosed.