Multi-Mini Transformers

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

Original poster: "Jolyon Vater Cox by way of Terry Fritz <teslalist-at-qwest-dot-net>" <jolyon-at-vatercox.freeserve.co.uk>

Has anyone on the List ever used a "multi-mini transformer" approach to 
implementing a high-voltage power supply for TC use?

By multi -mini transformer I refer to practice of using many mains 
step-down transformers "in reverse" with the mains windings connected in 
series to provide the required high voltage.

I was originally thinking connecting the low-voltage windings in series 
also, to connect across the mains supply
e.g. if the voltage rating of each winding were 6 volts then to facilitate 
connection to the UK mains supply of 240V AC, forty transformers would need 
to be connected (6V x 40 =240V on the "primary side
and on the secondary side, 240V x 40 =9600 volts, in theory.

But looking at this again it appears there may a problem with the 
interwinding/ core insulation
which may be insufficient to withstand the high voltages involved; for with 
a (non-grounded) voltage of 9600V on the secondary and 240V on the primary
the interwinding insulation on the transformers nearest to the ends of of 
the "stack" would be stressed by a maximum of (9600-240)/2 =4680 volts. Are 
mains transformers likely to be rated to withstand this?

Couldn't this percieved problem be mitigated to some extent by "floating" 
the low voltage winding, plus the core, of each of the "output" transformers
-by feeding it with low voltage from an identical "isolation" transformer 
-driven from the mains-
so that every one of the low voltage links between the input and the output 
transformers would be isolated from the mains, mains ground and other 
transformers in the stack?