High efficiency high frequency power oscillator

Abstract

The invention relates to a high frequency, high mechanical energy output apparatus comprising a transducer, a filter circuit, and a driving circuit. The transducer and the filter circuit are serially coupled together, and the transducer operates at its fundamental frequency of oscillatory motion. The driving circuit serves to drive the transducer at its fundamental frequency and comprises first and second active devices, wherein each active device has an output circuit and a control circuit. Each of the active devices are cooperatively connected together and are responsive to control signals for producing an alternating output signal. There is also provided means coupling the output circuits of the active devices to the transducer so that an alternating series current signal is applied serially through the transducer. The filter circuit filters from the alternating series current signal substantially all harmonics of the fundamental frequency of oscillation of the transducer to produce a filtered series current signal. There is also provided means for coupling the filtered series current signal to the control circuits of the active devices such that the filtered series current signal constitutes the control signal for controlling each of the first and second active devices for producing an output signal from the driving circuit substantially at the fundamental frequency.