Electrosurgery apparatus includes an r.f. power amplifier with an output to a patient electrode. The amplifier is controlled by the voltage of input signals from a control unit which receives a sample of the voltage and current of the output signal. The voltage and current signals are supplied to A/D...http://www.google.ca/patents/US4961047?utm_source=gb-gplus-sharePatent US4961047 - Electrical power control apparatus and methods
