# Re: High Voltage Output

```Original poster: "Gerry Reynolds" <gerryreynolds-at-earthlink-dot-net>

Hi Antonio,

You are right, my intuition was that inductance was proportional to the
number of turns, which was wrong.  I went back to the text books to find out
why the N^2 relationship and basically, if one uses the definition of
inductance L=flux/current and looks at the inductance of one turn, that
inductance will be proportional to the number of turns since the total flux
will be proportional to the number of turns.  So the total inductance is
proportional to the this single turn times the number of turns, hence the
N^2.  There will be a proportionality constant since not all turns are
perfectly coupled into this one turn.

Gerry R.

> Original poster: "Antonio Carlos M. de Queiroz" <acmdq-at-uol-dot-com.br>
>
> Tesla list wrote:
>  >
>  > Original poster: "Gerry Reynolds" <gerryreynolds-at-earthlink-dot-net>
>  >
>  > Hi Antonio,
>  >
>  > Would this be the sqrt of the turns ratio??
>
> No. The turns ratio, because for coils with identical geometries the
> inductance is proportional to the square of the number of turns, and
> for a transformer with high coupling coefficient, the mutual inductance
> is M=sqrt(L1*L2).
> The actual voltage gain of a transformer is A=M/L1, that for this
> value of M is equal to sqrt(L2/L1), that is equal to n2/n1 if the
> geometries of the coils are identical.
>
> Antonio Carlos M. de Queiroz
>
>

```