# Solid State transformer ratio's

```Malcolm

You wrote:
>>>> Finally, the driver step-up ratio is going to be ideal for only
>one operating power level with a particular secondary. I am unable to
>quantify this at the moment but am working on it.

There is a discussion of this in Duane Bylunds book - "Modern
Tesla Coil Theory".

He first of all states that the RMS impededance is the same
whether the coil is driven by a square wave, or a sin wave.
He then quotes the imedence turns ratio in a transformer
as SQROOT(Zp/Zs)=Np/Ns
Zp, Zs primary, secondary impedance, Np Ns number of turns.

Primary impedance Zp = E^2/P
E primary voltage and P maximum power from the supply.
or of course, Zp= E/I. So for the same transformer
could be used at different powers as long as V was proportional
to I.

He then assumes a secondary impedance of 500 ohm.
Which is the DC resistance of the coil.

Builds it, runs it measuring the current through the secondary.
With a current transformer and an oscilloscope.

He found however that the impedance of the coil
rises greatly when corona is produced and was unstable.

It looks like we are back to suck it and see.

Alan Sharp (UK).

```