My statements about voltage and current referred to ideal circuits,
which are immensely useful in gaining understanding of fundamental
circuit operation. One can argue for a long time about how perfect a
real circuit can be made, and I won't get into that. I hope I made my
point without the need to.

Roy Lewallen, W7EL

Bill Turner wrote:

On Tue, 19 Oct 2004 06:49:01 -0700, Tim Wescott
wrote:


An electron beam in a vacuum can flow current without any voltage drop,
as can a superconductor.


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I can't argue the superconductor, but in a vacuum tube there must be a
source of voltage to cause the current to flow. Even if you are talking
about the "contact potential" caused by a heated cathode, there is still
voltage present, isn't there? And of course, the anode voltage causes
current to flow there too.

--
Bill W6WRT