Patent ID: 7702702
Filing Date: 2010-04-20
Classification: G01R,H03H

Abstract:
1. A signal processing device which computes phase difference between two analog alternating signals through imposing the two analog alternating signals under a predetermined digital signal processing, the signal processing device comprising: a converting unit sampling the two alternating signals with a predetermined period and converting the sampled level values into digital alternating signal data; a filtering unit filtering the two digital alternating signal data generated by the converting unit so as to abstract digital alternating signal data x[k] and y[k], respectively, both having a predetermined frequency, the filtering unit comprising an adaptive digital filter; a differential computing unit computing two digital alternating signal data x′[k] and y′[k] which are differentials of the digital alternating signal data generated by the filtering unit based on Formulae 1-4 below; and a phase difference computing unit computing phase difference φ between the two digital alternating signal data x[k] and y[k] based on Formulae 5 and 6 below using the two digital alternating signal data x[k], y[k] generated by the filtering unit, and the two digital alternating signal data x′[k], y′[k] generated by the differential computing unit; where A