|
Propeller Head Plaza Technical and scientific discussion of amps, cables and other topics. |
|
|
|
Propeller Head Plaza Technical and scientific discussion of amps, cables and other topics. |
|
In Reply to: This turned my head around about how cables actually work. posted by mrod on February 4, 2022 at 10:17:18:
mrod,
Most of what he talks about is correct:
the electrical signals do not actually get carried inside the conductors, but rather, are represented by the electrical AND magnetic fields that are present for the most part OUTSIDE the wires.
I have been aware of this all my time as an Engineer, even though it was not specifically taught as such in school.
It can be helpful to think of the conductors as a set of "guide rails" for the EM fields, rather than the classic but misguided plumbing pipes concept.
He is wrong about the turn on of the light bulb, as EM fields do not propagate faster than the speed of light, and thus, the light bulb would not turn on for about 1 second after the switch was closed.
This would, of course, require a "perfect" set of conductors, with no inductance, no capacitance, and no resistance. He only mentions resistance, but implies the perfection of the other two parameters.
Real world wires (actually wire pairs), have all three, and due to the fact that most of the insulators are not a perfect dielectric, the velocity of propagation will be less than the speed of light, say somewhere between about 60% and 85% depending on the quality of the insulator dielectric.
I will cover some of the other aspects that this leads to with regard to audio cables, and why it does make a difference that the signal is not actually carried inside the wires, but for the most part, outside.
Jon Risch
This post is made possible by the generous support of people like you and our sponsors:
Follow Ups
- Mostly correct. - Jon Risch 17:24:08 02/06/22 (3)
- RE: Mostly correct. - geoffkait 17:28:50 02/08/22 (2)
- in a nutshell - DrChaos 16:06:48 02/11/22 (1)
- Think outside the nutshell - geoffkait 04:09:19 02/12/22 (0)
Top of Page ]
[ Contact Us ]
[ Support/Wish List ]
[ Copyright © 2024, Audio Asylum, all rights reserved ]
