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1) At 10:18 PM 4/18/00 -0700, Bob Sciamanda wrote:
loop law. It is
It is not necessary to place this burden on Kirchhof's
it even works forvalid even for non ideal capacitors and inductors; eg,
an open circuit - a highly fringing capacitor situation.
2) At 08:22 AM 4/19/00 -0400, Bob Sciamanda also wrote:
state, the net
Stating K's current law in the familiar form: "In steady
current into any point is zero", this is simply a statementof charge
conservation and applies even to volume current distributions. It issurface charge
inapplicable only during the transient startup when (mostly)
distributions are being established to drive the steadystate current.
If "steady state" means DC, then K's law has nothing to say about
capacitors of any kind, or about fringing fields, and is not
very useful.
If "steady state" includes "steady" AC signals, then
statement 2 is false
in context. Because of the fringing fields, there is a
nonzero AC current
into the node which Bob calls an "open circuit". The real
physics violates
Kirchhoff's assumptions.
I renew the assertion that as applied to ordinary circuits,
Kirchhoff's
laws are tantamount to assuming that circuit elements are
black boxes, and
that there are no significant electric fields outside of
"capacitor" black
boxes, and no significant magnetic fields outside of "inductor or
transformer" black boxes.