FIELD: physics.
SUBSTANCE: invention relates to electrical measurement techniques. The method can be used in apparatus for measuring passive and active complex values of alternating current, for example in alternating current bridges to measure parametres of multiple-element two-terminal networks by improving a branched bridge measuring circuit at the same time with several test effects with different frequencies, as well as when measuring in case of several harmonic interferences. The method involves obtaining projections 
and 
of a measured signal Sj(t)=Ajsin(2πt/Tj+φ0j) on two orthogonal reference signals by adding the sample sum of synergetic signals σ(t), sampling instants of which make up sets {ti'}j and {Ti"=ti'+Tj/4}, which are formed using a step-wise procedure from an initial set, which consists of one arbitrary initial time instant t0, by obtaining at the first step an additional set which also consists of one instant, by shifting the initial set to an odd number of half-periods of the first signal, and then obtaining at the second step an additional set which consists of two instants, by shifting two instants of the overall set obtained at the first step, to an odd number of half-periods of the second signal and the procedure is continued with formation of an additional set on each step by shifting the overall set, formed at the previous step, to an odd number of half-periods of the next signal and with doubling on each step the number of instants for sampling the sum of the synergetic signals until the number of step equals M-1, and amplitude Aj phase shift φ0j of signal Sj(t) is determined from the following expressions: 
for 
where ti'=ti+t0, t1=0, t2=t1+n1T1/2, t3=t1+n2T2/2, t4=t2+n2T2/2, t5=t1+n3T3/2, t6=t2+n3T3/2, t7=t3+n3T3/2, t8=t4+n3T3/2,……, t2m+1=t1+nm+1Tm+1/2, t2m+2=t2+nm+1Tm+1/2,…, t2m+1=t2m+nm+1Tm+1/2,…, t2m-1=t2 m-2+τM, 
m≠j.
EFFECT: possibility of accurate real time measurement of any synergetic harmonic signals with known periods, as well as possibility of simultaneous measurement of several signals under the condition that, the frequency of the measured signal is not a multiple of frequencies of synergetic signals.
2 dwg
