Thanks for the better diagrams guys -- Threw mine together in about 5 minutes late last night!
Uppey,
Just to point out that the diagram in Scott's post of a 240V secondary with center-tap grounded is the standard arrangement for a domestic supply in North America.
With the U.K. 110V power-tool supplies, we only ever connect across the two outer "live" lines to get the full transformer secondary voltage.
In the American/Canadian domestic system, all three lines are brought into the house. Lights and outlets for most small appliances are then wired from one "hot" line to the neutral to run on 120V, while big appliances (range, dryer, etc.) are connected across the two hots to get 240V.
It's the same basic principle as the U.K. site supplies, though, with a center-tap ground on the transformer secondary.
