If you are new to z scale you may think you can just grab an old controller and hook it up to your z scale track and you are ready to roll. You could do that…………however, to insure proper operation and avoid damaging your z sale locomotives, make sure you purchase a controller that meets the power requirements. There are a couple of choices for you, Marklin and Rokuhan being the most common. Rokuhan makes a very nice compact controller that has the proper power output for the tiny z scale engines. The RC02 controller features constant lighting and you can snap on remote turnout controls as needed. The unit can be operated on AA batteries or you can purchase a AC adapter separately. Click here for more info and a video on setting up the Rokuhan RC02 controller.
DCC is another option for controlling your z scale railroad. Amazon offers some great books on the subject along with some nice DCC starter sets.