Revisiting the Power Explanation
Cecil Moore wrote in
:
Owen Duffy wrote:
This gets confusing. You are talking about "the amount of EM wave
energy contained in a transmission line" and now you qualify it with
"values averaged over an integer number of RF cycles in one second".
Average energy over time is POWER... are you talking about power and
foxing us by calling it energy. I am confused.
I have been convinced by Jim, AC6XG, to abandon the word
"power" because of the difference in definitions between
the field of physics and the field of RF engineering.
Jim would argue with you and say that average energy over
time is NOT necessarily POWER and is only power if actual
work is done which, of course, is not done by a reflected
wave.
So you need to go off and argue with Jim over the
definition of "power". Instead of talking about power,
Jim has convinced me to talk about watts or joules/sec
which he says are not necessarily power. The confusion
comes from the field of physics, not from me. While you
are talking to Jim, get him to explain the definition
of "transfer".
A neat diversion from the issue re the "amount of energy" qualified later
as a average over time which is a different quantity, Joules vs Watts to
many of us.
The fact is that the energy stored in a transmission line in the steady
state is in the general case, a time variable, and you cannot state the
energy (in joules) at a point in time knowing only forward and reflected
power and the one way propagation time.
So Cecil,
Is it all about semantics? Is the lack of a shared language the cause of
difficulty understanding your concepts. You wouldn't be alone, Art
experiences the same difficulties with convention.
Owen
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