摘要 |
An electrosurgical unit for producing a modulated oscillating signal for coagulation procedures and an unmodulated oscillating signal for cutting procedures. The unit includes a four arm bridge rectifier interconnected directly to the line voltage. A first pair of opposing diagonal terminals on the rectifier is connected directly to the line voltage. A cutting signal is obtained from the other pair of diagonal terminals, and a coagulation signal is obtained across one arm of the bridge rectifier. An oscillator tank coil provides the necessary RF isolation output. A switch selectively interconnects either the coagulation signal output from the bridge rectifier, or the cutting signal output from the bridge rectifier, to the oscillator. The output is taken across the tank circuit from the RF oscillator and applied to a patient through a handpiece. Through the use of high voltage transistors in the circuit, high efficiency is obtained by eliminating the input transformer of the prior art.
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