# HOW MUCH POWER NEEDED FOR A TC?

```HELP!

As you maybe know I am designing a new TC to be built at the High Voltage
Institute, Helsinki University of Technology.

The current problem is that the professor mentoring my project DOESN'T
BELIEVE my new TC will require 20 kW of power!

He wants to have some clear justifications for it, as he thinks a huge part
of the power is not wasted (!) or (another explanation) the most of it is
just reactive (not real) power.

The TC I am designing has got the following characteristics:

- secondary 15.7" diameter, 59" tall, 88 mH, f=102 kHz (57 kHz loaded)
- primary 78 uH flat pancake
- top load toroid inner dia. 9.8", outer dia. 59", about 61 pF
- primary capacitor 0.1 uF
- break rate adjustable up to 800 BPS.

Looking at the other coiler's TC I decided 16 kW would be a proper power,
20 kW just to leave some margin.

I NEED YOUR HELP TO JUSTIFY THIS MY DECISION (or to change it, if needed):

- how to show relationship between coil size and needed power (to get some
decent performance)?
- how to show were the power is dissipated and that it's not simply
reactive?

My professor is going to measure the power absorbed by my present TC
(secondary 4.33", 19.7" tall) and to extrapolate it: I think he will
measure about 2 kW and multiplying by four (new TC is 3 times taller) will
easily end up with 8 kW only (!).

If I am not able to explain to him the above issues he will not let me
build it with a 20 kW tank supply... :(

Waiting for help...

P.S. Here the question is not "How much power do I need at 800 BPS with a
0.1 uF capacitor". The real question is "In general, how much power do I
need to excite a TC of this size?".
My tentative design featured a 10 kV transformer, rectified to a 14 kV DC,
that using resonant charging ramps up to 30 kV to charge the primary
capacitor. At 800 BPS the energy is  E = 800 * 0.5 * 0.1E-6 * 30000 * 30000
= 36 kW.
Limiting power to 20 kW I could charge the capacitor (-at-800 BPS) to about 22
kV, more than sufficient.

```