# [TCML] 1 Mhz ,1 kw

Sat Mar 21 11:21:16 MST 2009

```bartb wrote:
> Hi Dex,
>
> Well, stepping outside the box, then you can't really keep to turn
> parameters, but you can keep to other parameters. So....
>
> 4" x 20" sec, 230 turns of 12 awg, h/d=5, DCR=0.38 Ohms, ACR=11.4 Ohms,
> Q roughly 550.
> Flat primary, 7"ID, 9.042"OD, 0.25" tube, 0.5" pitch, 2 turns. Center of
> tube even with bottom sec turn. Coupling = 0.114.
> Toroid with center disc, 5" x 20" (1" spacing from top winding to bottom
> of toroid).
> Tank Cap, STR, 0.01uF.
> Sec bottom turn starting at 20" off the ground.
> 1.023MHz and tuned.
>
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.
```