For a Type S transformer Lionelsoni said, “Connect terminal U to the outside rails, A to the center rail, and C to the center wires of the controllers. Don’t connect anything to the center terminals of the turnouts. This will give you 10-19 volts for the train and 19 volts all the time for the turnouts.”
Reference: http://cs.trains.com/ctt/f/95/t/192167.aspx?sort=ASC&pi350=2
Other Lionelsoni posts on 1122 constant voltage wiring: http://cs.trains.com/ctt/f/95/p/187663/2050689.aspx#2050689 http://cs.trains.com/ctt/f/95/p/166790/1833122.aspx#1833122 http://cs.trains.com/ctt/f/95/p/192167/2097609.aspx#2097609 http://pictures.olsenstoy.com/cd/swt/stc1121a.pdf
Lionel LLC described the internal rewiring of 1122 switches in their Lionelllc blog: http://lionelllc.wordpress.com/projects-and-tips/wiring-your-layout/preparing-switches-for-constant-voltage/
There is also a video on youtube: Wiring Lionel Switches for Fixed Voltage: http://youtu.be/_0McntbmQ9I
Hope that helps.