News for hackers. Stuff that matters.

A comment on Ohm Overlooked. Parent comment

Re:Ohm Overlooked by projektfu on Saturday April 09, 2022 @11:41AM (#30968987)
The potential difference can be measured between any two points in a circuit, but EMF is the source of electrical energy such as a battery or generator that produces the potential difference that can be considered to "drive" the circuit.

As I understand it, an EMF has to come from nonelectrical energy, such as chemical, thermal, mechanical, or electromagnetic energy. So if you are drawing your circuit with a battery, you could call that EMF but if you are drawing it with a generic voltage source, you would not call that EMF per se.

[ Parent | on HN ]
Re:Ohm Overlooked by sacrosancty on Sunday April 10, 2022 @02:47PM (#30980364)
That 2nd distinction seems weirdly unreal. Is there an example of a real generic voltage source that only uses electrical energy and not those other types, or are you just referring to an idealization that you might use in a circuit diagram?
[ Parent | on HN ]
Re:Ohm Overlooked by projektfu on Tuesday April 12, 2022 @06:16AM (#31000681)
Many voltage sources are themselves circuits and the EMF element would be hidden therein.
[ Parent | on HN ]
Re:Ohm Overlooked by sacrosancty on Sunday April 17, 2022 @01:33PM (#31062561)
Hmm. So is it that an EMF can't be carried along conductors like voltage can and is only the original source of the electrical energy with no circuitry?
[ Parent | on HN ]