Can I put 2 transformer in series?

[Tube747]

Hello!
Can I put 2 identical power transformer (115V primary and 6.3VCT secondary) in
series and get 230V primary and 6.3VCT on secondary)?

Thank!

[Alan Douglas]

Hi,

>Can I put 2 identical power transformer (115V primary and 6.3VCT secondary) in
>series and get 230V primary and 6.3VCT on secondary)?

Yes. You might want to put a lamp in series when you first run it,
just in case you get the phasing wrong. Measure the two primary
voltages to be sure they're equal.

73, Alan

[Alan Douglas]

Back again,

I forgot to mention that the two secondaries *must* be parallelled.

73, Alan

[Alan Douglas]

Hi,

>Are you meaning that putting the primary in series and secondary in parallel of
>2 identical transformers for 230V primary and 6.3VCT on the secondary?

Yes.
>
>I heard the people said that it's better to use 2 transformers which has 115
>primary for 230V instead of "one single" transformer that has 230V at the
>beginning. Is that correct?

It's certainly not better; in fact it's a kludge and not all that
safe, but it will "work" if you only have 115 (120)V transformers.
>
>Finally, do you think 2 transformer (primary in series and secondary in
>parallel) will affect the efficiency of the transformers itself?

A little less efficient, not enough to worry about.

73, Alan