SENSITIVITY VARIABLE LOOP GAIN OSCILLATOR SENSOR SYSTEM

摘要

A sensor system on an oscillator having variable loop gain level is described. Only when the oscillator loop gain is at least the level of one does the oscillator produce an AC output signal. The oscillator's ability to oscillate is controlled by the one or more sensor/transducer input signal levels which controls the Q level of an element in a resonate circuit which with other components forms a feedback network.

主权项

1. A sensor system providing an output signal level dependant on an input signal level comprising;
an amplifier to provide signal gain, a first feedback network to provide negative feedback from said amplifier output to said amplifier input, a second feedback network to provide positive feedback from said amplifier output to said amplifier input, said first or second feedback network includes a resonate circuit, while other said first or second feedback network provides a constant gain level feedback from said amplifier output to said amplifier input, said resonate circuit impedance level responsive to proximity of external objects, said impedance level controls gain level of said first or second feedback network, said amplifier having loop gain level responsive to said impedance level, and said amplifier oscillating to produce an AC output signal with said AC output signal level responsive to said loop gain level.