RADIOFREQUENCY ELECTROSURGICAL GENERATOR WITH CURRENT CONTROL

摘要

The invention realises a radio knife powered by an electronic circuit that operates with high-frequency current wherein said circuit comprises: a rectifier circuit (20) fed by the mains voltage that supplies rectified pulsating voltage (201) to a radiofrequency circuit (30); a radiofrequency circuit (30) capable of emitting an output current signal (301) with a constant frequency in the scale of the MHz, powering the radio knife by mean s of a radiofrequency transformer (40). Said radiofrequency circuit (30) is obtained by piloting a MOS (305) through a pilot circuit (306) comprising a quartz-operated oscillator whose oscillation frequency amounts to a least twice the usual operating frequency of the MOS. The pilot circuit (306) is controlled by microprocessor current control circuit (310) that takes a sign al proportional to the current from a current sensor (308) positioned after the MOS (305) and is such as to maintain the radiofrequency circuit current limited to a value compatible with the power that can be dissipated by the M OS independently of any variation in the circuit load impedance.