I have set up a handy way to switch track power from 18 volts for engine running to variable 0to15 volts for trolley operation. I have block controllers routing power for 16 blocks from 3 transformers. I wanted to run my trolley from a short parking siding along about twenty feet of track to my passenger station. This involves power from 2 blocks. I have my TMCC tracks programmed for full power. I have installed a relay from digitech in the circuits between the two block controllers and the busses which provide the power to the tracks. The fixed track voltage passes thru the relay via the normally closed terminals of the relay for train operation. The relay is powered thru a switch on the edge of the layout with 12 volts fixed power. A variable voltage circuit which originates at my Accessory voltage controller supplies power thru the normally open contacts of the relay to the same busses which provide full voltage to the 2 affected blocks. In normal operation with the relay turned off, full track power is supplied for TMCC train operation. when th relay switch is thrown, the track voltage is turned off and the variable voltage is supplied to the two trolley blocks and the two sidings. Since the AVC provides this power, I can dial up 12 volts and let the trolley run back and forth on its route from parked to station and back. after the trolley has made several runs, I park it on its siding and kill the low voltage by turning off the relay, restoring full voltage to the blocks. I plan to add a detector at the station end to empty the MTH passenger platform when the trolley pulls in. I am also looking into a ZSTUFF trolley controller to provide announcements and programmed stops along the route. All in all a pretty neat setup. I only have to be careful to route any trains which were traveling these 2 blocks to different areas while running the trolley.
I hope this is clear and may be useful to some of you!
Bob Taylor
