Patent ID: 8866399

Claim:
A method for controlling a high intensity discharge lamp, the method comprising: supplying a signal of periodically fluctuating frequency and constant filling factor of 50% supplied from an electronic switches cascade of a half-bridge type that is connected with a ballast circuit, wherein the ballast circuit includes at least a first condenser, a lamp, a first inductance, and a second condenser forming a resonant circuit, wherein during an ignition mode of the lamp, the supplied signal is an exciting signal that periodically fluctuates between a first frequency F min and a second frequency F max and ignites the lamp, the second frequency F max being higher than the first frequency F min and lower than a third frequency F stat , the third frequency F stat being lower than a resonant frequency F res of the resonant circuit, and wherein a voltage having a constant frequency F stat generated on the second condenser would be sufficient to ignite the lamp.