I had been planning to allow my guests to run these two MTH Storage Tank Operating Stations since I started my layout five years ago. I thought of different methods using micro limit switches, or hall-effect sensors, and an Arduino. But then I came across these very inexpensive (less than $5 each) programmable timers, some of which have a Form-C (SPDT) relay, and thought I would give it a whirl. In less than an hour I had the system running, and I like it. The Timers are mounted under the layout.
Timer functions:
Timer-1 sets the total time for the entire operation, provides a 12VDC output, and can be triggered by a switch or an IR sensor mounted on the fascia of the layout.
Timer-2 has two time settings and a Form-C relay with SPDT output. Time (a) is the total time for the Operating Station bridges to lower, and Time (b) is the total time for the bridges to rise back to starting position.
Timer-3 also has two time settings and a Form-C relay with SPDT output. Time (a) controls lowering the Station-1 bridge, and Time (b) controls lowering the Station-2 bridge.
Timer-4 also has two time settings and a Form-C relay with SPDT output. Time (a) controls raising the Station-1 bridge, and Time (b) controls raising the Station-2 bridge.
The entire system runs on 12VDC, and the timers can be programmed to keep time to a 1/10 of a second. I played with it for a while to get the times about right, but once in a while, after several runs, the bridges are not quite where they should be. This is not a problem as I have the Stations also wired to toggle switches on the control panel, so I can manually run them home easily.
I still have to tweak the timers a little bit as I may be off a 1/10 or 2/10 of a second, but it is running well enough to show.
Enjoy, and thank you for watching.
Alex
