Patent ID: 8656897

Claim:
A device for generating radiofrequency plasma comprising: a voltage generator configured to output voltage at a voltage setpoint; at least one ignition assembly, the ignition assembly comprising: a spark plug that generates a spark between two electrodes of the plug when a voltage level is applied to the plug; and a switch positioned between a power supply terminal of the plug and an output of the voltage generator, the switch configured to electrically and selectively connect the output of the voltage generator to the power supply terminal of the plug upon receipt of a control signal applied to a control terminal of the switch; an electronic control unit electrically connected to the control terminal of the switch and configured to generate the control signal, the electronic control unit including measuring means for measuring at least two values representative of a trend over time of the output voltage from the voltage generator, including a first measurement taken at a start of conduction of the control signal and a second measurement taken before an end of conduction of the control signal; and means for varying the voltage and/or the frequency of the electrical current applied to the power supply terminal of the plug according to a new nominal voltage setpoint at the output of the voltage generator based on the values measured by the measuring means, wherein the electronic control unit is configured to calculate an energy transfer rate according to the following equation: energy_transfer ⁢ _rate ⁢ ( x ) = Vstart_all ⁢ ( x ) 2 - Vend_all ⁢ ( x ) 2 Vstart_all ⁢ ( x ) 2 , with Vstart_all(x) being the first measurement and Vend_all(x) being the second measurement, and the energy transfer rate calculated by the electronic control unit is compared with theoretical energy transfer rate values to generate a correction value, and the correction value is added to the energy transfer rate calculated by the electronic control unit to determine the new nominal voltage setpoint at the output of the voltage generator.