# [TCML] Primary # of turns on a 10KVA 14400 pole pig

David Dean deano at deanostoybox.com
Sun Jul 19 20:16:19 MDT 2009

```Hi Jim

On Sunday 19 July 2009 06:46:52 pm Jim Mora wrote:

> Hi All,
>
>
>
> Does anyone know the usual primary turns (240v side) on a 10KVA pig and the
> wire gauge? I have a dry core with 36.875"^2 area and am looking at Finn
> Manner's transformer project page.
> http://www.hvtesla.com/radartransformer.html This is a heavy core!
> According to Finn, turns equal K=1.6 for 60hz (K* E)/Area
Looks like K=6.5 for 60Hz on that page to me.
> so(1.6*240)/36.875" to fully magnetize the core.  This would be only 10.41
> turns. Yikes. Is that right?
>
For that area probably more like 30 turns. If the core is bare you can wind 10
turns of scrap wire on it and using a variac voltmeter and ampmeter plot the
saturation curve for the core. The highest voltage you get before the current
starts to rise faster for the same increase in voltage is the threshold of
saturation. The number of turns divided by that voltage gives you the
turns/volt required to stay linear. Multiply that times the voltage you want to
stay linear at and you have the required number of turns for the primary.
>
>
> Thanks,
>
> Jim Mora
>
later
deano

```