Re: Series-ing Potential Transformers

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: Tesla729-at-cs-dot-com 

In a message dated 10/25/03 2:33:23 PM Pacific Daylight Time, 
tesla-at-pupman-dot-com writes:
>In the case of 2 PTs hooked with a common center ground and each PT has the
>same winding direction, each PT would hit a postive peak and negative peak
>at the same time so the output would not be twice what the single xmfr would
>give.  Each PT would hit 14.4 kV and then back to 0 kV as their phased
>outputs would be exactly matched.
>
>You can try it, but unless you have a very strange PT this won't work.
>
>Dr. Resonance

Hi Dr. R, Gregory,

I respectfully beg to differ. My two PTs (and any two similar transformers
for that matter) can certainly be hooked up where the two secondary
outputs can be seriesed w/ their outputs 180 degrees out of phase
so their voltages will add together (two PTs, each w/ 7200 volts out
will yield 14400 volts in this fashion. If the two outputs of the PTs
aren't 180 degrees out of phase w/ each other at first, then simply
reverse the primary input leads to only one of the transformers, just
like you would for two MOTs.

<Hi Dave,
<Wouldn't it be less stressful on the insulation if you just run the
<transformers series opposed like an NST? Just ground one side of the
<dual-bushing PT and swap the AC input wires. Now you have 7200 volts on
<each terminal, opposite polarity, for 14,400 total.

<Regards,
<Gregory

Yes, I'm sure it would be, but it would be a whole lot more dangerous
for yours truly since both of my PARALLELED 10kV, 100 uFD quarter
shrinker/can crusher caps are of the welded metal can type w/ one HV
terminal  and the metal can acting as the other terminal. I am really
against the idea of the outer metal casing of two 140 lb. 5kJ energy
discharge caps floating -at- 5000 volts when full charged! {:^0 Besides,
I never run the PTs to their full rated voltage as I only need to get the
loaded voltage up to 10kVDC to fully charge the capacitors. I just
need the higher unloaded voltage from the 2 seriesed PTs to more
rapidly charge the huge caps. Bottom line though is that I'd rather
lose a couple of PTs than to lose my life!


David Rieben