Hi guys,
I think that in both this thread and the "speaker cable life span" thread a lot of the disagreement may be resulting from differing interpretations of the words "drift" and "flow."
If ac is applied to a cable, a given electron will "move" (aka "drift") an EXTREMELY small but non-zero distance during the first half-cycle of the waveform. During the second half-cycle of the waveform, it will move back to where it started. That movement will repeat for as long as the same signal is present.
On average, electrons at all points along a given conductor of the cable will do the same thing. The movement of electrons near the destination end of the cable will lag the movement of electrons near the driven end of the cable by a miniscule amount of time corresponding to the signal propagation velocity, which will be in the rough vicinity of 50 to 90% of the speed of light in a vacuum.
Although the individual electrons are moving back and forth across an infinitesimal distance, if we define a cross-section of the cable at any given point, and if ON AN RMS-AVERAGED BASIS, 6.241 x 10exp18 electrons move past that cross section in each second (in either direction), then 1 ampere of ac current is "flowing."
Meanwhile "charge" is conducted from one end of the cable to the other at near light speed, as I indicated. The charge is carried at the destination end of the cable by electrons that are not the same electrons as the ones near the source end of the cable, but which move similarly.
Agreed?
Best regards,
-- Al
