RE: Math help...

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "John H. Couture by way of Terry Fritz <twftesla-at-qwest-dot-net>" <couturejh-at-worldnet.att-dot-net>

Bert -

I agree with your excellent comments below, however, I believe it should be
pointed out that the energy transfer in all magnetic circuits is 100%
because there are no losses in magnetic circuits. Electric losses are only
in electric circuits and the efficiency is the ratio of output/input. This
means that when reffering to electrical efficiency the input and output
calcs should be shown. This can be a difficult task when talking about Tesla
coils.

I understand the voltage can be used to find the joules (energy) in the
primary capacitor but how do you determine the energy in the secondary
circuit when the secondary voltage of an operating TC is an unknown? I
avoided this problem by using a light bulb for the secondary load in my
test.

When we say the TC efficiency can be about 90/95% what are the input and
output conditions? Coilers talk about TC efficiencies but I have never seen
any published input/output calcs. In my TC Construction Guide page 14-4 I
show a simple efficiency test I made with a small TC and the input/output
calcs were shown. Have any other coilers made these tests? The test showed
an overall efficiency of 56%. Larger coils have efficiencies much lower.
What are the input and output calcs for the 90 to 95% efficiencies? How do
they relate to the overall efficiency? How do these 90/95% efficiencies vary
with TC size?

John Couture

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-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Sunday, July 08, 2001 9:02 PM
To: tesla-at-pupman-dot-com
Subject: Re: Math help...

Original poster: "Bert Hickman by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<bert.hickman-at-aquila-dot-net>

Josh and all,

That's an excellent question, Josh - and it goes to show that very few
things are truly simple in coiling... :^)

Malcolm is correct. Previous experiments have measured primary tank
capacitor voltage during a complete primary-secondary-primary energy
transfer cycle. These have shown that the efficiency of the first
primary-to-secondary transfer (from an initially charged tank capacitor to
a fully resonating secondary) can indeed exceed 90%. However, this makes no
statement regarding how efficiently we were able to charge the tank cap
from the mains supply in the first place. For that, we need to talk a bit
more about capacitor charging circuits...

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