# Re: Re: Grounds

```Hi Mark,

Thanks for your very clear explanation on why a Tesla coil needs a good
ground to work effectively. You helped kill off a few incorrect ideas I had

Anyway, here's  a few more questions for ya if you have a spare moment!

MG: increasing, the same is true with the capacitive reactance because the
capacitance to ground is DEcreasing, thus the total impedance of the
of the coil rises as you approch the top of the coil. The impedance at the
top is the highest thus that is where the voltage is the highest, the
impedance at the base is the lowest, that is where the current is the
highest. The ground is the common connection in the circuit that connects

Ok impedance=voltage/current , so high impedance means high voltage. But hold
on: in a series LCR circuit isnt the high voltage due to a high current
flowing thru a high reactance? So if we regard the Tesla coil as a series LCR
circuit shouldn't the current be large throughout the coil - including the
top end of the coil? (Is the current that flows in a series LCR circuit the
same anywhere in the circuit?)

MG:Thats why improving the ground, or
increasing the size of the terminal capacitance will improve coil
operation,
it increases the current flow in the secondary coil as long as
there is enough power being fed to it to take advantage of it. Increasing
the terminal size lowers the impedance at the top of the coil increasing
the current flow in the entire secondary coil.

Lets see if I get this: increasing the terminal size increases the
capacitance of the top of the coil. So the capacitance between the top of the
coil and the ground is bigger. This means that capacitive reactance is
smaller so more current flows in the circuit. But at resonance isnt the
current that flows in a series LCR circuit only limited by the resistance as
capacitive reactance and Inductive reactance kill each other?

Another thing that I dont understand is this wireless transmission of power
thru ground currents. If we have ground currents flowing wont this ground
current try to capacitively couple to the top of the coil and so "complete
the circuit" instead of flowing miles away to light a distant lightbulb on
top of another coil?

Sorry about all these questions but I am really bamboozled trying to
understand how a Tesla coil works. Just when I think I have a handle on it
some new facts come along that blow my ideas to hell.

Best Regards,
Mark

-- Mark
_/_/_/   _/_/_/_/       Mark Conway
_/    _/    _/          Deep Thought BBS, Auckland, New Zealand
_/    _/    _/          A FirstClass(tm) Macintosh GUI BBS
_/_/_/      _/          Internet: mconway-at-deepthnk.kiwi.gen.nz

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