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2 Posts
Discussion Starter · #1 ·
I need help working an HO dwarf signal light with my Shinohara point.

Scale: HO
Controller: ECoS ESU
Decoder: SwitchPilot Servo (51802) May 2008 version
Servo: Tower Pro (SG90)
Yard Light: Green over Red (2mm LEDs made Railroad 2 aspects Dwarf Signals Lights Green/Red - three wires, red, green, common)

Basically, I have used all 4 positions for servos on the SwitchPilot and want to wire Dwarf yard lights indicating which routs are active. I understand how to wire the yard light directly to the track. However, I would rather have them connected through the decoder if possible.

1) Can this be done without having to purchase a SwitchPilot Extender?
2) If so how should I wire it?
3) If not, how does the dwarf light get wired to the SwitchPilot Extender so that it works when I switch the point?

Any thoughts/assistance would be greatly appreciated... :>)

· Registered
1,005 Posts
You need some form of switch to control the signal. Connecting the signal to the track is by far the easiest way to do what you are trying to do, whatever you have in place to switch the frog polarity can switch the point position indicator too.

1. Yes, but not if you are adverse to wiring the signal to the track.

2. Put a reverse protection diode across each LED, connect the common of the two LEDs to the point frog and connect the other legs of the signal via resistors (experiment with value but start with 1K and see how it goes) one to each of the stock rails.

3.Connect the signal common and the switchpilot extension 'com' terminal to a suitable DC power supply, connect the switchpilot extension 'I' terminal to one leg of your signal with a series resistor, and connect the switchpilot 'II' terminal to the other leg of your signal via a series resistor.

All quite simple and straightforward. In practice if you are going to the expense of buying the Switchpilot Extension, use it to switch the frog polarity and wire your point position indicator to the track - it will save a lot of messing about and give you maximum reliability.

· Registered
999 Posts
There are two independent sets of terminals A and B for each of the SwitchPilot Extension ports. So you could use the A set to switch frog polarity and the B set to switch the supply to your signals. So forget all this wiring the signals to the track business. It is unnecessary if you use SwitchPilot Extension.

You could wire the signals so that when one road shows red the other shows green and vice versa using just the B terminals, by wiring the red LED from signal 1 and the green LED from signal 2 to terminal I and the the red LED from signal 2 and the green LED from signal 1 to terminal II. Then when you sentd the command to change hhe point the frog polarity and the signal aspects will change as well.

A word of caution, when using SwitchPilot Extension with SwitchPilot Servo t oswitch the frog polarity. Make sure that CV49 is set to use the "decelerated" values to delay switching of the ports on SP Extension. Otherwise the Extension could switch the frog polarity before the point blades have moved and cause a short.

· Administrator
10,743 Posts
I have provided power for a signal lamp in my semaphore by tapping the 5v rail to the servo. The circuit can be deduced from this post - link - in the topic where I blogged building the second signal.

I control my signals and points using Switch Pilots Servos and Switch Pilot Extensions.

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