Electroscapel circuit with a variable output frequency

摘要

A circuit for an electroscalpel or a device for diathermy by conduction current with frequencies from 100 kHz up to 10 MHz, comprises a resonant serial filter consisting of an inductance LS1 and a capacitance CS1, and a resonant parallel filter consisting of an inductance LP and a capacitance CP. The resonant serial filter and the resonant parallel filter are synthonised to allow a fundamental signal of an input signal to pass through and also simultaneously attenuate exponentially other harmonics of the input signal as the frequency of the harmonics increases. The resonant serial and parallel filters are separated by a transformer TRF with a turn ratio of 1: N, N being a real number. The output frequency of the circuit is variable and the circuit and/or frequency can therefore be synthonised to match output impedances of the circuit to an impedance dependent on a patient and the electrodes of the electroscalpel or device for diathermy