I had a 4:1 single phase step-down transformer. Primary winding was provided the mains supply (225V) and output (secondary) was 57V. I was under the impression that capacitive coupling b/w primary and secondary was noticeable only in high-voltage transformers, and thus in this case (low voltage) the two windings would practically be electrically isolated.(adsbygoogle = window.adsbygoogle || []).push({});

However, when I measured the voltage b/w each of the primary (P1, P2) and secondary (S1, S2) terminals, I got significantly large values:

S1->P1: 204V

S2->P1: 154V

S1->P2: 6V

S2->P2: 44V

Are these values because of capacitive coupling?

I tried modelling this situation (Please have a look at the attached image. The arrows above primary and below secondary show assumed polarity). Then I wanted to find out the values of x and y through simultaneous linear equations, using the above values. But the first problem was that the meter showed RMS values which couldn't be negative, and secondly, this method didn't turn out to be correct either because all the different equations actually boiled down to a single equation. Is my model correct? How can I find the values of x and y?

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# Transformer Capacitive Coupling

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