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infamis
 
Posts: n/a
Default Question about how RCA wires & headphone mini-jacks "work".

In article , "Richard Crowley" wrote:
Rememer that there are several *different* ways of using
the word "ground". Don't assume that they all mean the
same thing. Many words in English (and likely other
languages also) have several different meanings. We
must determine which meaning is appropriate or we
will be confused.


Exactly. That's what I keep forgetting. But how would you know which meaning
of ground someone means if all you saw was the ground symbol on a schematic?
How would you know it meant ground as in the "reference" point (like the
shield of the RCA interconnect) or as a connection to the chassis/power line?
I guess it depends on the context, just like the definition of a particular
word depends on the context in which it's used? I guess I just don't know
enough to decipher which meaning (for now).


I felt that my above description did not meet the requirements of
circuit is why I am confused.


Any connection that conveys a signal/power from one
point to another is a "circuit".


Right, and since my original drawing didn't meet the definition of a circuit
was why I was confused (since I thought my drawing was the technically correct
of how stuff works). But now I understand I need not worry about that now
since I don't care about the earth (in this particular discussion).

Generator.A - transformer - "earth" - Generator.B


One terminal of the generator is connected to a ground rod.
The other terminal is connected to a wire that travels many
miles across countless power poles to the transformer which
supplies your home. That wire connects to the primary of the
transformer. The other side of the primary conects to ground
at the base of the pole.

The current starts at the generator, travels many miles over
the power pole wires, connects to the transformer outside
your house, then then current travels back many miles through
the crust of the earth to the generator completing the "circuit".
A "circuit" is a circular path. I urge you AGAIN to read all the
dictionary definitions of the word "circuit".


I get it. I think I was just disregarding the earth as a conductor since when
I think of conductor, I think shiny metal. I know it's wrong, as a conductor
is a material that has little resistivity to the flow of electrons.

Don't really know what you mean by "where is it going"?
Your circuit would be complete and operational without
your "ground" connection. Where is *what* going?


I was adding the "ground" definition as a connection to something called
ground (like for instance, the chassis). So my drawing would still be correct
if instead of the wire connecting the bottom terminal of the AC signal to the
bottom terminal of the amp, both the AC terminal & amp terminal had a short
line drawn connected to a "ground" symbol?

Take the circuit you drew. Now make a mirror image
of it and connect the two "grounds" together. That is
what you have with a stereo mini-jack. Each circuit
(the left circuit and the right circuit) is a complete
path in itself and doesn't care what the other one is
doing or whether it is connected to it or not. Follow
the current flow around the "circuit".

Just as you can take your original diagram and either
connect the ground point to the earth, or not. The
circuit doesn't care because the current is flowing
through the circular path (the "circuit") and is complete
in itself.

The common node of the stereo mini-phone connector
(the "sleeve") carries the return current for BOTH the
left channel "circuit" and the right channel "circuit".


Wow, I think I'm starting to get it.