If I were to take a transformer with 3 coils and a DC power supply, attach both leads of the bottom coil to the positive and both leads of the top coil to the negative, would anything come out of the middle coil?

what about if I were to take the same transformer and two A power supplies, attached one supply to the bottom coil and the other to the top coil, would I get twice the power out of the center coil?

 

The VA rating of a transformer is largely dependent on the size of the core and the gauge of wire used.
You cannot double this rating.
DC will not work.
Max.

 

interesting. thanks for the info!

 

If I were to take a transformer with 3 coils and a DC power supply, attach both leads of the bottom coil to the positive and both leads of the top coil to the negative, would anything come out of the middle coil?

Nope.