# [TCML] 1 Mhz ,1 kw

bartb bartb at classictesla.com
Sat Mar 21 14:42:46 MST 2009

```Dex originally specified 1000W input to the coil and not gap delivery,
so that is where I started.

Looking at 1000W input, 15kV needs at least a 90mA transformer. I
believe Dex is in 100V 50Hz land (could be wrong). With the .01uF cap
size, cap energy is in the 2.25j range and bps is going to be up in the
neighborhood of 260 (ignoring zero crossing, re-ignition, and all that
nasty stuff). Roughly getting 600W across the gap with a 300kV terminal
voltage. This is very similar to the norm. As long as the caps don't get
overly lossy with the frequency, the only real problem I see are
whatever affects the low turns will have. If the terminal voltage
remains a product of the inductances and considering the geometry, it
should work (nothing stands out to me why it wouldn't).

Bart

jimlux wrote:
> with 0.01uF primary capacitor, and figuring you want, say, 200 bps to
> get that kW through, means you need to hold 5 Joules.
>
> E=0.5 * C * V^2
> 5*2 = 0.01 * V^2
> 1000 = v^2
> v =sqrt(1000) = 31kV.. that's a challenge...not insanely high, but
> still challenging.
>
> Series L in the capacitor will be an issue (usually neglected in most
> 100kHz scale TC designs).  For a fres of about 1 MHz and a C of
> 0.01uF, the L is going to be about 2-2.5 uH.  Wire is about 1uH/meter..
>
> Say you wanted to stack up a bunch of the 942P scale caps to get to a
> 40kV rating.. that's 20 of them at 2kV each (0.15uF each would get you
> to 0.0075 uF, which is in the ballpark).. they're about 2cm long, so
> you've got 40cm just in physical length (although careful arrangement
> might reduce the L from that source), plus whatever the ESL of the cap
> is.
>
>
```