I am very impressed with the ability to unwind a transformer in a way that will allow it to be rewound with the same wire. That requires a great deal of motivation and a fair amount of skill..

And a fair amount of patience ha.

 

If a 230V primary has 900 turns, then a 420V secondary should have 1640 turns, and that is pretty close to 9 x 175.

 

If a 230V primary has 900 turns, then a 420V secondary should have 1640 turns, and that is pretty close to 9 x 175.

Yes, but the 9x 0.06mm wire are soldered together at each end , won't that just count has one !

 

Yes, but the 9x 0.06mm wire are soldered together at each end , won't that just count has one !

Certainly turns in parallel such as the 9 strands will count as only the turns of the whole conductor.
and for a non-loaded condition the winding voltage ratio of a transformer is the same as the turns ratio. So now I am wondering if it is possible that the actual voltage is less, and that to get the 420 volts this winding was connected in series with the primary winding in an additive manner? Given that we have not seen the actual application circuit that could be the case. That would be one explanation that is physically possible.
OR, it may be that the "420 volt" claim for the winding was in error.

 

So now I am wondering if it is possible that the actual voltage is less, and that to get the 420 volts this winding was connected in series with the primary winding in an additive manner?

That would make more sense. A primary that was tapped 0-120-240-415 (or 0-115-230-400) and a low voltage secondary, with the primary on one section of the bobbin and the secondary on the other.
Unfortunately the number of turns would still be wrong, as it would need 665.

 

OK, one thing that sort of points to the windings being in series is that they are on separate bobbins, and the main reason for separate bobbins is to isolate the mains voltage portion from the rest of the windings.

And now, if the high test voltage was DC, then there could easily be a voltage multiplier that we have not heard about. Doublers and triplers are common circuits.

 

This is what I received from the makers of the Transformer.

"Many thanks for your recent enquiry.



Provided that the part is TT1418, the voltages should be:

Primary: 0 – 110 – 240 V
Secondary 1: 0 – 420 V @ 3 mA
Secondary 2: 0 – 6 V @ 32 A
Secondary 3: 0 – 13.2 V @ 400 mA

Please keep in mind that the last drawing we have on record is to issue 9. In issue 7 there is a comment about wind 1 changing; this is the primary winding and may not be so consequential if you are only interested in the secondaries".

 

It sort of seems that they do not have much more information than we have.
A 32 amp transformer winding would be at least #10 wire, and be delivering about 200 watts. At 100 watts per square inch of core, that is a fair sized transformer.