Model Railroad Switching

I would like to use Arduino to control switching on my model railroad and I need a bit of help. There is already one pretty good solution out there, but it is very proprietary and for that reason I'm trying to use Arduino. The switch motors are Circuitron Tortoise slow motion switch machines. They require very little power.

Particularly I want the ability to control multiple switches with just one button, so I hit one button and all the needed switches line up as they need to be. That obviously is super easy with Arduino.

The issue I have is how to power the switches. I saw that in another forum someone is using h-bridges and that seems like a good option. But I want to control as many as possible with a single Arduino, and do so as cheaply as possible.

The switches only require 4ma during operation and 15 to 16 ma during stall and need 9 to 12 volts DC.

So would h-bridges be my best bet? I'm not terribly good with electronic circuits, so simplicity is also important to me.


If you want them to switch all together simply wire them up to the same bridge circuit. You can use a relay or h-bridge, it can't be simpler because you need the current to flow in both directions depending on if you open or close the switch. It looks to me like there is a motor in those switches, is that correct? Read this on motors:-

Well each switch does need to be independent, most of them anyhow, some may be able to be connected to the same circuit but it would only be a few. But when one switch moves so that a train can move through it, most times another switch needs to move as well, that’s where arduino comes in.

So I need to figure out a way to move as many switches as possible independently. An h-bridge seems like its a good option, but seems to require a lot of output pins, creating more cost.

but seems to require a lot of output pins, creating more cost.

Only 2 outputs per switch. It is easy enough to fit a port expander onto an arduino to give you more in chunks of 16 per chip for less than $2 per chip.