Everything on model trains, model railroads, model railways, locomotives, model train layouts, scenery, wiring, DCC and more. Enjoy the world's best hobby... model railroading!
Switch Machines and Power
Ethan asks readers for advice:
“Hey guys. I have been thinking about starting up my own model railroad in either HO or N scale and including a switching yard and a few sidings. I got to looking into the wiring for switch machines and decided that I want to use toggle switches with indicating lights. However, I noticed that most toggle switches will constantly power the switch to whichever line it is switched to. Will this not burn up the motor by constantly feeding it power trying to get it to move even after it has switched the turn out?”
6 Responses to Switch Machines and Power
Leave a Reply
SUBMIT YOUR QUESTION
Download Your Free Catalog
Use Tiny Railroad Micro Controllers
Model Train Help Ebook
I think that would happen. My experience with point motor switches is that they are momentary on like a pulse as the switch is operated. An electronics guru could work out a way of constantly lighting an indicator and pulsing the motor when required. I used to have Tri-ang ones and if the switch lever got stuck, it burned the motor out.
Robert
Try using servos as they will work with toggle switches and will power track indicating lights.
Ethan Switch motors such as Tortoise switch motors are rigged for constant power and also has circuits just for light circuits when the switch is thrown and when the switch sets in the new position it also connects the circuit for your lights that are not connected directly to your power for the switch motor. There are several other switch motors available that can do the same thing too.
Snap switch motors work with a momentary push button and and the switch will snap to the new position. Atlas is an example of that. (but these motors do not have special circuits that can operate lights) Powering snap switches that way I suggest a master power switch that you turn on just before selecting the switch button to operate. I had a guest one time at my layout and they accidentally leaned on my buttons and they smoked about 8 switch motors before I new what happened. Each switch had smoke coming from them. I am wiring up Tortoise motors to a simple 2 way toggle switch and once the switch motor reaches its stop position it no longer leave power on the motor. It also has 2 other circuits that you can power light indicators and also signals for your trains all in one. The tortoise has worked very well with my hand laid switches.
from Newman
Frequently used is the double pole double throw (DPDT) “spring loaded centre off” type of switch, which returns itself to the middle position after operation in either direction.
It is wired to change the current direction according to which way it is pressed.
These switches work great but to keep an accidental move of the switch get one that you have to pull out slightly so it can be moved one way or the other. from Newman
It appears that you are referring to Twin Coil Switch machines when you say motor…
If that is true, then you do not want to have continuous power to them. You have to use Momentary on toggle switches for this. I love the indicating lights idea, and their are several ways to do it. The Tortoise allows you to put Bi-color LED’s in series with the switch machine because they only use about 15ma, and you reverse the current to control the machine, and it’s always on. The Tortoise is pretty bulky but works great. Tam Valley uses a small servo motor, and a DCC addressable control board, that has the color LED’s right on it, and can be panel mounted. These aren’t too bulky, the cost is not bad, and they are great. For the twin coil switch machines, there were some out there that came with multiple contacts, that you can connect to lights, similar to the NJ International 6000 NJI Twin Coil Switch Machine.