Patent ID: 7663321

Claim:
An electrical supply device configured to deliver energy to a structure that includes at least first and second electrodes and a space containing a gas to be excited, the device comprising: a voltage generator; an inductor in the form of a transformer provided with a primary winding and with a secondary winding, the primary winding connected to the voltage generator and the secondary winding connected to the first and second electrodes to supply the first and second electrodes with a periodic voltage of a frequency; and resonance means for fixing the frequency at substantially the resonant frequency of the system of the structure and the inductor; wherein the resonance means comprises a switch placed in a path from the voltage generator to the primary winding of the transformer, and a control system connected to the switch to open and close the switch over a period, wherein closing of the switch, which is closed for a duration, is triggered by choice at one of the following instants: at a zero crossing of the current flowing through the structure; when the voltage crosses a threshold voltage; at a threshold light level; or when the current flowing through the structure crosses a threshold current.