Selecting Transformers for Power Supply

[Hailstorm350]

Hello again,
My ongoing project for a Pedal Power Supply is continuing
I am searching for a suitable Dual Secondary Transformer to buy 4 or 5 of and hook up to regulators and what not.
But the trouble lies in how to select a suitable one for the job.
I look in catalogs and for dual secondary pt's they have printed series and parallel Amperage and Voltage readings, what does this mean?
How do I select one that puts out 12.6V on both secondaries.

I have found a sutable enclosure and just need to select a transformer small enough to satisfy my space limitations.
Thanks,
Ken

[R.G.]

Things in parallel have the same voltage, by definition. So when you have two windings in parallel, the voltage is the voltage of either secondary by itself.

The voltage across voltage sources in series adds, so when you have two secondaries in series, the voltage is twice that of one secondary.

If you want two 12Vac secondaries, you want 12Vac in parallel and 24Vac in series. The series current rating is the rating of either secondary by itself.

[Hailstorm350]

Yet another Thanks R.G.
Ken