[Prev][Next][Index][Thread]
Re: Tesla Coil toroid Size
> Original Poster: "John H. Couture" <couturejh-at-worldnet.att-dot-net>
>
>
> Malcolm -
>
> Can you show your calculations using my RMS numbers and your
> instantaneous numbers to arrive at your conclusions?
>
> John Couture
> -------------------------
Be happy to.
You wrote:
> >
> >> For example if the input is 960 watts and the bks are 120 and the
sparks
> >> are 2 feet long then the TC is producing 8 watts per break (including
> >> losses) and four watts per foot of spark.
960W = 120/s * 8J
Remember that J = W-s
An example:
I have observed energy disappearing in one coil in just 25uS. Let us
be really generous and say 50uS. Since 120/s = a period of 8.3333mS
from start of one gap fire to start of the next ,the coil is
exhibiting a duty cycle = 0.000050/0.008333 = 0.006 or just 0.6%
That 8J is disappearing in the output discharge and gap during the
50uS so the peak power equivalent = 8J/50uS = 160kW The shorter the
time period during which the energy is dissipated, the higher the
peak power in the coil.
Note that there is a very considerable quiet period of (0.008333
- 0.000050)s = 0.008283s or if you like, 8.283mS between gap fires
or "bangs" as I define them.
BTW, the dissipation time is not guesswork. Anybody using a storage
scope can capture these waveforms and measure them to within a couple
of microseconds at worst. I think nobody here would doubt that
remaining ringing at a few percent of initial amplitude is not
significant, remembering that energy at the peak of oscillation is
proportional to V^2 and a drop of just 30% represents a 50% energy
loss. Visit Greg Leyh's site for scope pictures of a really high
powered system (you have haven't you??). Look at the scope photos I
indirectly provided you with of a sparking coil. Better still, get a
scope and *measure it*.
Malcolm
> >By that logic, one can produce a 100 foot spark using 1W. In fact the
> >TC is discharging 8 *Joules* per break. The low duty cycle turns that
> >energy in the attendant period of time into kW if not MW pulses.
<snip>