If I had a Toroidal transformer with 2 x 115V primaries, i.e. suitable for 115V Mains and 230V mains as most commercially available ones are, then is there any reason why I can't wire the 115V primaries in parallel on UK mains in order to double the output Voltage?
I was thinking about the commonly and cheaply available 2 x 55V secondaries that wired in series will give 110V and if the primaries were paralleled, logically you'd get 220V which becomes a useful Voltage for Valve Circuits.
If it's ok to do this, would it be advisable to de rate the VA rating?
I figured that the insulation must be capable of withstanding UK mains voltage when wired in series, so there shouldn't be an issue of insulation breakdown, and I am not advocating this practice to get a higher voltage from a high voltage secondary.
It's just that 2 x 55V toroids are freely and cheaply available, whereas high voltage ones tend to be "specialist" windings and as one offs expensive.
I know some here can wind their own but apart from one instance of modifying a low voltage secondary under advice of the Gent who made it (Thanks Joe Bog
) and it was a right old faff on if very effective, I have no real ambition to get involved in transformer manufacturing.
Regards and Thanks in advance.
Andy.