Richard Harrison wrote:
Cecil, W5DXP wrote:
However the VARS in the standing wave require energy which can be
converted to watts---."
VARS is an acronym for Volt Amps Reactive.
Apparent power can include real power and VARS. I would think that VARS
all have volts and amps in quadrature (at 90 degrees). If so, power is
VI cos theta. WI cos 90 degrees = VI (0)= 0, thus the power in VARS is
0.
It takes joules of energy for VARS to exist. Any time one
wants to give up the VARS, they can be converted to watts,
just like the energy stored in a capacitor can be converted
to watts by connecting a resistor.
The VARS stored in the standing waves in a transmission line
can be converted to watts by connecting a load equal to the
Z0 of the line. Of course, the standing waves cease to exist
in the process. One cannot have one's cake and eat it too.
--
73, Cecil
http://www.w5dxp.com