ON THIS WIKI
When powering a block which holds the track, the track and every connected track below it will be powered. When powered, the track will lift any minecart up to the top block which is powered. When unpowered, it will lower a minecart down the vertical surface.
When a cart reaches the top, it will automatically push it up and over the edge. If it's stopped partway up, it will boost the cart onto a track placed on the opposing side from the elevator track. This allows you to create elevators which stop at different floors.