44. MRH13-10-Oct2013-P.pdf - page 54

Up the Creek Column - 7
The Dual 3-Way controllers come from the factory pro-
grammed for minimum semaphore movement. The servos may
be small, but they are quite powerful. Having the default servo
positions for red, yellow, and green aspects close to the cen-
ter of travel helps avoid damaging delicate semaphore blade
assemblies by attempting to operate them beyond their limits.
The select, up, and down push buttons on the servo controller
are used to program how far the controller should move the
servos (and semaphore blades). This allows for relatively pre-
cise setting of positions for the red, yellow, and green aspects.
You can download a PDF format Dual 3-Way manual here.
The Tomar lower quadrant train order semaphores also
include an operating light that illuminates the appropriate
... On to next page of text 
16: A Tam Valley Dual 3-Way servo controller.
15
index contents
MRH-Oct 2013