Yes, I assumed that but, as I said, loads have to be primary restive if they are going to actually consume any energy (i.e. 'work'
). I'm not quite sure what you are saying here. The simple way of reading the energy (VA) being consumed is as shown, above although it's more likely to be at much lower voltage.
I wasn't talking about practical implementations but, rather of the exercise of explaining why the phase of the induced voltage in the CT relative to the phase of the supply is an indication of 'flow direction' - something which could have been illustrated without having that voltage adding or subtracting from the supply voltage.
I'm not sure I understand that. The transformer on the right is presumably a standard 'voltage transformer' with a 10:1 turns ratio - but that means that for a 1A current going to the load, the meter would (with flow in the direction you indicate) read "34 V" - but if you connected the CT 'the wrong way around' it would read"14 V" - neither of which appear to be immediately/directly 'meaningful'?
It is the simplest way to describe the operation without having to introduce some form of comparator
Yes, if you look back at my initial description the reading is shown as 340V & 140V without transformer. The additive combination running at much lower voltage (typically 1 to10V min to max) is virtually the elderly detector format used to remotely measure power or feed into BMS systems.
It's quite easy to detect the phase relationshipHowever, that's all irrelevant to my understanding of how direction of flow can be detected (by phase relationship between supply voltage and voltage induced in the CT) - and for that enlightenment I very much thank you
Kind Regards, John
Generating a graph between -+2.4A (IE staying within the red areas) against detector output voltage will produce what looks to be a straight line (I haven't tried plotting so it may be incorrect) from 0V at -2.4A through 240V at zeroA to 480V at +2.4A. It only needs to be compared with 240V to see which direction the current is flowing and my hunch also the power drawn is also linear.
Fair enough - but, as I said, 'implementation' (with 'a comparator' or anything else) was not what I was interested in, it being the concept that is what I was missing, and which you have kindly explained.
Sure. If you're back to 'implementation' again then, yes, there are plenty of ways to skin that particular cat.
This appears to be a duplicate of most of post #64, to which I replied in #65.
I have no idea how that happened as once #64 was posted the draft would have not been there.
Very odd. I blame poltergeists, or maybe 'global warming' or (a pretty universal scapegoat at present)
I'm not even sure If I was still usingthe PC at that time.Very odd. I blame poltergeists, or maybe 'global warming' or (a pretty universal scapegoat at present)
Maybe not - I almost included Donald Trump in the list of 'currently universal scapegoats'
Yeah Fremlins beer seemed toʻ create lots of trips
Yep, those are the fellas
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