Patent ID: 7717910

Claim:
An electrosurgical generator for supplying radio frequency (RF) power to an electrosurgical instrument for cutting or vaporising tissue, the generator comprising: an RF output stage having at least one RF power device, at least one pair of output lines for delivering RF power from the RF power device to the instrument, and a series-resonant output network coupled between the RF power device and the pair of output lines; and a power supply stage which is coupled to the RF output stage and includes: a charge-storing element for supplying power to each RF power device, the power supply stage being configured such that the charge-storing element is capable of storing charge in excess of 5 joules; a voltage-sensing circuit arranged to sense voltage supplied to the RF output stage by the charge-storing element; and a pulsing circuit coupled to the voltage sensing circuit for pulsing each RF power device; the arrangement of the voltage sensing and pulsing circuits being such that a timing of the pulses is varied in response to the sensed voltage.