Re: center tapped transformers

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "D.C. Cox" <resonance@xxxxxxxxxx>



You really can't insulate the case on this type of xmfr.  The HV 
would just jump to the power wires, like the neutral which is also a 
ground source. The pri to sec insulation is not good for 12 kV and 
would rapidly breakdown.

These xmfrs are insulated for each winding to provide 6 kV plus and 6 
kV minus at the same time.  The insulation is only good for 6 
kV.  Trying to ground one bushing and force the other to 12 kV just 
won't work as the xmfr internals are not made to operate at this potential.

These types of xmfrs are made to be inexpensive and work only for the 
purpose they are intended --- not TC service.

If you wish to go this route better to use a potential xmfr which can 
have one bushing grounded.

Dr. Resonance


> There is a question I asked myself over and over again since the 
> first time I've seen a schematic for a Tesla coil on the net: Why do 
> coilers ground the center tap of the secondary of the high voltage 
> transformer (NST or OBIT) instead of just doing the opposite 
> (insulating the case from ground very carefully or cut the 
> connection of the secondary to the case)? As far as I know this 
> would be safer since touching one of the output wires (or being 
> accidently connected to one by a streamer) wouldn't electrocute you 
> in this case since the output terminals weren't hot in respect to ground.
>
> Regards, Q.