why transformer is a machine?
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Hi me2010! Welcome to PF!
That's a little vague … I'm not sure what you mean.
What is the context?
Is this part of a larger question, or part of a longer quotation from a book?
Strictly, a machine is a mechanism for doing mechanical work. So a transformer isn't a true machine.
I would have agreed with the last poster, until looking this up on the Web. It seems that more than one University syllabus groups transformers with other electric machines (such as generators and motors and indeed motor/generator combinations, which might be where they see the commonality). Could this be a light-current versus heavy current thing - maybe the power guys have always classified transformers that way?
If the original poster attends one of these institutions, he/she might get more credit for describing the common points between a transformer and other electrical machines, than arguing semantics with the teachers. After all, I suppose you could regard a transformer as having something in common with a lever or a gearbox. Similar rules apply, in that you can trade voltage for current (compared to force versus velocity), but their product can only be the same at most, actually always less due to losses.
There are certainly some mathematical forms in common AB=C. But that applies to gases, dynamics and chemistry as much as to levers and transformers.
People might just be a bit 'approximate' in their use of terms.
With a transformer you can trade off between two quantities at a given fixed power. Question for OP: which two quantities am I referring to?
A transformer is deliberately designed, with a ratio to chosen to adapt a source to its load. The same is true for a gear ratio selected to match an engine to its (mechanical) load.
In those other fields you have mentioned, are there similarly designed adapting systems? Here I have to confess to my ignorance of these subjects.
I take the point about machines performing a 'matching' function. I guess we are just seeing a change of word usage, along the same lines as 'search engine'.
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