The Booster Circuit
Now that the mechanics of the dispenser have been completed...

continue the Booster loop under the station and then loop it back to the station level.

Then break the track and build a 3 x 3 loop as shown.

Hollow out another booster channel for this 3 x 3 loop but instead of the usual 4 blocks, make this 6 blocks long for added power.

The basic construction is complete so you can place 2 carts in now.