[TCML] Calculate Output Voltage

[Jim Lux]

-----Original Message-----
>From: Clive Hansen <mrclivehansen at gmail.com>
>Sent: Nov 15, 2007 11:33 AM
>To: Tesla Coil Mailing List <tesla at pupman.com>
>Subject: [TCML] Calculate Output Voltage
>
>Hello,
>    I was wondering if anybody knows of a formula to calculate the 
>secondary voltage of a Tesla coil. The only one I thought to try was 
>Vout=(Vin/Pri)Sec which should work with a standard transformer if Vout 
>is voltage out, Vin is volts in, Pri is primary turns, and Sec is 
>secondary turns. However, this seems to be returning an extremely high 
>voltage.
>
>Thanks,
>Clive

If there were no breakout or losses, you could calculate the voltage more as the ratio of inductances or capacitances, assuming all the energy transfers from primary to secondary.  It doesn't but that will bound it.

In real life, the voltage is limited by sparks/corona forming on the secondary topload.  You can bound this by using the 3MV/meter breakdown for air.  If the radius of curvature is, say, 10cm (8 inch diameter), then the maximum voltage it can reach is 300kV, and that's for a nice smooth surface with no bumps.