Sensing circuit

Abstract

The present invention discloses a sensing circuit including a sensing device, a first amplifier circuit, a high-pass filter, a second amplifier circuit and a determination circuit. The sensing device produces a sensing signal. The first amplifier circuit reduces high-frequency components of the sensing signal and amplifies low-frequency components of the sensing signal to produce a first amplified signal. The high-pass filter removes the direct current of the first amplified signal to produce a filtered signal. The second amplifier amplifies low-frequency components of the filtered signal according to a first predetermined voltage to produce a second amplified signal. The determination circuit determines whether the second amplified signal is higher than a second predetermined voltage and lower than a third predetermined voltage, and produces a detection result when the second amplified signal is higher than the second predetermined voltage or lower than the third predetermined voltage.

Dependencies are inferred from the claim text.