[SOLVED] Question about transformer

[billouris]

Hello guys and gals. I opened up a UPS the other day and i found a toroidal transformer that had only 3 wires. i would appreciate some help on how to wire it. The transformer was plugged in the board . No wires from the mains.

 

[FvM]

If you review the connection to other parts of the UPS, you have good chances to understand it's purpose.

 

[billouris]

thanks. i did figure it out. its an auto transformer. thanks for the inspiration : p