Method to detect amplitude and offset variations in two electrical sinusoidal signals 90 degrees out of phase and also circuitry to implement this method and the use of this method in a control system

摘要

In order to detect amplitude and/or offset deviations in two electrical sinusoidal signals (S1, S2) 90 DEG out of phase, both signals (S1, S2) are weighted via threshold stages (K11, K12, K21, K22). The zero crossings of one signal (S1, S2) in each case specify sampling times (1up, 1down, 2up, 2down) for the amplitude of the other signal (S2, S1). The output signals (X1, X2, A, A, B, B) of the threshold stages (K11, K12, K21, K22) are analysed in a processor. Control can be effected in accordance with the errors detected. …IMAGE…