|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
50.164.204.218
In Reply to: RE: It flows back into the secondary of the power transformer posted by jedrider on August 24, 2015 at 10:24:38
In an AC current, the electrons don't flow anywhere, they just move back and forth.
You guys really shoud do some basic reading on alternating current and drift velocity. Here's a couple of starters:
https://en.wikipedia.org/wiki/Alternating_current
https://van.physics.illinois.edu/qa/listing.php?id=3341
http://pfnicholls.com/physics/current.html
https://en.wikipedia.org/wiki/Drift_velocity
The last link has a pretty good example of a 1mm diameter conductor passing a 3 amp current, which equates to 36W into a 4 ohm speaker load or 72W into 8 ohms. If the signal is 60 Hz, the electrons (on average) move back and forth a mere 2.1 micrometers and their net movement over time is zero.
Follow Ups:
Couple 'gotchas'.
First, don't electrons move at some fraction of the speed of light? 2 microns is only 20,000 angstroms and would be a velocity (linear) of 120 microns per second. That seems REAL slow. Though on AVERAGE, the net movement IS Zero.
And it doesn't matter to your example, but what's important would be VA, based on the power factor of the load. Not that it matters to your example.
I periodically connect a D-cell battery to my speaker leads and 'transfuse' new electrons into the wire. The sound improvement is terrific. I think electrons must wear out.
Too much is never enough
The links I posted explain why the drift velocity is so slow. Basically, copper wire has A LOT of free electrons.
The current determines the number of electrons per second flowing through the conductor. If you take the number of free electrons per unit length of the conductor and divide that by the number of electrons per second flowing, it will give you the bulk velocity of the electrons. For a 10 AWG speaker wire carrying 1 amp, the velocity is just 1.77x10-6 m/s.
Like I said, there's a lot of free electrons in copper wire. In a typical 3m length of 10 AWG speaker cable, about 1.34x10^24 of them, which is equivalent to about 60 amp-hours. So a D-cell isn't going to cut it. You would need to empty a car battery to move electrons all the way through the 3m length of wire.
Post a Followup:
FAQ |
Post a Message! |
Forgot Password? |
|
||||||||||||||
|
This post is made possible by the generous support of people like you and our sponsors: