I have just started installing Dapol signals and the BLOCK Signalling Dapol Semaphore Signal Controller DAP1A and BOCK signalling Infra-Red Semaphore Signal Controller for Dapol Signals DAP2 the issue is the Power Supply as the module is designed for a supply voltage of 16V AC. There are separate output terminals on the module which are connected to the input terminals, and so provide the same voltage to the signals. However the issue I have is can you use 12 volt as it really doesn't make things very easy. The signals are the 4L-001-003 Dapol GWR Round Post Semaphore Signal – Home and Distant In the old days the only 16V AC supply available on a layout is the auxiliary output on an old DC controller, like the H&M Duet. The PDf instruction doesn’t explain the voltage requirements very well do I need a separate power pack and if what type (Aust power 240volt) and can I use 12 volts or will it fail. Hopefully I have explained myself.