Patent ID: 8519643

Claim:
A method of operating luminaries, said method comprising the steps of: providing one or more fluorescent tubes that contain mercury vapor gas and at least one electrode located at ends of the fluorescent tubes, a fixture that comprises holding and connection devices for the fluorescent tubes, and a ballast for driving the fluorescent tubes, each of the electrodes includes a heating filament cathode; applying voltage pulses to the electrodes for exciting the mercury vapor gas, the pulses consisting of non-periodic voltage levels separated by variable duration dead times being of alternative form including amplitudes of equal values but of positive and negative polarity; maintaining the dead times of the pulses as long as a resonance effect in the mercury vapor gas maintains light emission, wherein the resonance effect is determined from real time samplings of a current flow crossing the one or more fluorescent tubes; producing alternative voltage pulses from the ballast; and using the ballast to activate couplings of connection/fixation on each end of the fluorescent tubes, the couplings being configured to short cut the filaments of the electrodes of the fluorescent tubes respectively, to cancel the current through the electrodes, and to thus avoid the losses in voltage.