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Ian Field Ian Field is offline
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Default 180 degrees out of phase



wrote in message
news:alpine.BSF.2.00.1405181650420.37808@bunrab...
On Fri, 16 May 2014, Uncle Peter wrote:

But I wonder if it would help reduce the meter reading?

No. The coil and the capacitor add up (ideally) to zero impedence, so it's
like you put a wire accoss the mains. It burns and/or the breaker/fuse
opens. For real components the coil & cap still cancel out and leave
basically the resistance of the coil, which for a ``large'' coil is
probably small, so again bad things happen.

But you have a basic fallacy anyway. At resonance the current is /in/
phase with the voltage, the capacitive and inductive reactance cancel out
so the circuit looks purely resistive.

If you like complex impedences (and adding a bit of series R &
using the EE jxj=-1 & w standing in for omega = 2 pi f)

XL=jwL
XC=1/jwC
Z=jwL+1/jwC+R

at resonance w=sqrt(1/LC)
Z=j( sqrt(1/LC)L-1/sqrt(1/LC)C )+R=j( sqrt(L/C)-sqrt(L/C) )+R=R
I=V/R


Peter did all that fancy math at uni, he can do the phase reversal in his
head - by attaching a pair of electrodes either side and passing the whole
meter current through it.