Patent ID: 6939347
Filing Date: 2005-09-06
Classification: A61B

Abstract:
1. An electrosurgical generator, comprising: a current mode power supply operative to convert pulses of input current occurring at a predetermined switching frequency into a DC output voltage; an RF amplifier and output section receptive of the DC output voltage and operative to create an output RF electrosurgical waveform from energizing pulses having a voltage related to the DC output voltage and a time width related to a characteristic of the RF electrosurgical waveform; and wherein: the current mode power supply includes a current mode controller for supplying a switching signal to define and control the pulses of input current and a frequency control circuit external of and connected to the current mode controller; the frequency control circuit responding to the DC output voltage to supply a frequency control signal to the current mode controller, the frequency control circuit supplying and maintaining the frequency control signal at a first value in response to a relatively higher value of the DC output voltage, the frequency control circuit also supplying and maintaining the frequency control signal at a second value in response to a relatively lower value of the DC output voltage; and the current mode controller responding to the frequency control signal to maintain the switching signal at a predetermined higher rate in response to and for the duration of the first value of the frequency control signal and to maintain the switching signal at a predetermined lower rate in response to and for the duration of the second value of the frequency control signal.