# Re: SSTC does 10 foot sparks

```Original poster: "John Couture" <johncouture-at-bellsouth-dot-net>

Steve -

Thank you for trying to help coilers understand the difference between
energy and power.

Yips! You missed quoted what I said. I did not mean to covey the impression
that I though that power could be somehow made equal to energy. This again
shows how easy it is to confuse energy and power.

You said
"Note: The energy efficiency as described by John is the same as (average
power out/average power in"

I actually said
"Note that when using average power that you are adding time to the power
units which brings you into the energy unit solution."

I definitely did not mean to convey that average power was energy.
Average power is a power unit. Energy is an energy unit.

Power and energy like apples and oranges are not equal or should they be
compared as equals.

Don't feel bad. This power/energy battle has been going on for a long time
on the List. The problem is still in much of todays literature. For example
I was just reading about power on the internet and it mentioned power
consumption. On the surface this sounds OK. However, power is like volts or
amps and to say these paremeters are consumed doesn't make sense. But energy
is a quantity of electricity and this can be consumed.

Also be careful with how you use PSpice and other simulators. Energy has to
do with efficiency. Efficiency with simulaors can be GIGO.

John Couture

--------------------------------------

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Monday, June 21, 2004 9:05 AM
Subject: RE: SSTC does 10 foot sparks

> Original poster: "Steve Conner" <steve.conner-at-optosci-dot-com>
>
>  >Do you know that the power output of your Tesla coil
>  >can be much greater than the power input?
>
> Oh wow, then I can feed the output back to the input and get a TC that
runs
> for ever, and powers my house too ::)
>
> Seriously though, John is talking about PEAK power. This is hard to
measure
> directly, but we can do it by "fitting" a PSpice simulation to give very
> similar waveforms, voltages, and currents to what we observe
experimentally,
> and then asking PSpice to calculate the power for us.
>
> It may not be super accurate, but I estimate it is there to within +/-
15%.
> I have done the numbers for a coil design similar to Steve's ISSTC II, and
> the peak output power (from H-bridge to primary) is around 250kW, which is
> certainly more than the 4.8kW he is putting in. (The OLTC II had 130kW
peak
> output, but ran out of steam after about 60 microseconds.)
>
> I also estimate that the energy efficiency (as John defined it) of an
ISSTC
> is considerably greater than 75%. I calculated the OLTC II to be 75% and
the
> ISSTC is probably somewhat more efficient again, I would say 85%.
>
> The margin of error in these estimates is 10% (ie the ISSTC could be
> anywhere between 75% and 95% efficient)
>
> Note: The energy efficiency as described by John is the same as (average
> power out/average power in)
>
> Steve C.
>
>
>

```