Hi Don,
Yes, it's a 0.5 ohm resistor.? I noted this in the post just before the one you cited.
In general, I don't think that a single cycle of a set of AC waveforms is sufficient to assess a phase difference between or among them, especially when the prior or subsequent cycle has a different pattern or when the state of the associated components or other signals change during the cycle of interest.? In such cases, I'm inclined to try to figure out what's going on by looking at the signals themselves rather than where the peaks or zero crossings are.?
My interpretation of the waveforms in image TEK0049 in the post you cited is that the saturation occurred late in the first half cycle.? As you noted, saturation is not a sudden transition, so there was probably a little bit of back EMF left, plus the voltage was dropping at the time. That, plus the various resistances in the transformer and the rest of the circuit limited the current to at most 49A.
Since we don't have several cycles during which the saturation state is the same, we don't see a current trace in phase with the voltage trace.? Instead, the voltage goes to the other polarity and pulls the core back out of saturation until the voltage swings positive again.?
Just after the first half-cycle of voltage, the current is still positive for a moment while the voltage has turned negative.? If the transformer was in full saturation and thus fully resistive at this time, I think the current would have fallen to zero when the voltage also crossed zero.? The presence of persistent current seems to portray that there's an inductive component to the transformer at that time.?
Cheers,
Halden VE7UTS
