Physical quantity detecting device using interpolation to provide highly precise and accurate measurements

摘要

In a physical quantity detecting device for converting a physical quantity into changes in the cycle of a pulse signal and for amplifying the cycle to convert it into digital data, detecting accuracy is improved by increasing the sampling frequency without reducing the degree of the amplification of the cycle of the signal. In a physical quantity detecting device wherein pulse signals having oscillation frequencies changing depending on the ambient strength of magnetism are output from oscillators and wherein the cycles of the pulse signals are amplified by counters and decoder portions and are input to a pulse phase difference encoding circuit to convert the phase difference into digital data, the digital data is interpolated using the pulse signal from one of the oscillators as a sampling signal. This makes it possible to interpolate the digital data to accurately detect the strength of magnetism without providing a special oscillation device for inputting a sampling signal to the interpolation circuit.