I need a simple circuit I can use to indicate which way a turnout is switched. I have a momentary contact switch to actually move the turnout, but I’d like to have two LEDs I can mount on a track diagram to show which way the turnout is currently pointing. I know how to do this with 2 buttons for each direction, but I don’y know how to do this with one button for each direction.
All help gratefully appreciated!
You need a switch to control the lights.
Some turnout motors have switches/contacts built into them for this purpose.
If you’re using Atlas turnout motors, the basic motor that comes with the turnouts doesn’t have the switch you need. Their ‘deluxe’ turnout motor has another set of contacts that could be used to power indicator lights.
I tried using a contact switch from Radio Shack to power the frog of an Atlas turnout on which I was using a basic Atlas turnout motor, but the switch required too much pressure to work with the Atlas turnout motor.
Since the switch is hidden, I made contacts out of brass strip and attached another brass strip to the bottom of the throwbar, so it completes my circuit as it moves from side to side.
Not sure how long it will work or how reliable it will be, and it’s rather crude looking, but it’s working at the moment.
You might be able to rig something up that was all below the layout. Your input wire is attached to a pole on the throwbar, and the contacts are connected to each light. The other lead on each light goes back to ground.
Good luck!
Eric
Atlas makes a relay that can be wired in parallel with a twin coil switch machine.
There are a few options. For some of my turnouts, I bought a few latching relays. These are wired in parallel with the twin-coil Atlas or Peco switch machines, and provide the necessary contact closures. They’re relatively cheap - just a few dollars each. You will need to do some soldering, though, as the low-cost ones are designed for circuit-board mounting, and don’t have screw terminals.
Atlas makes a sepaate relay unit which does the same thing, but costs a bunch more. The “deluxe” switch machines mentioned above are their under-table mount units, which are designed with a 1-inch vertical throwbar, so if you’ve got a 3/4 inch subroadbed and 1/4 inch roadbed, you’re OK with them, but most other configurations would make them tough to use.
This guy:
http://www3.sympatico.ca/kstapleton3/751D.HTM
has a circuit which mounts on your control panel. It includes a toggle. I’ve installed 2 of his “751D” units, and they work as advertised. They do require a separate power supply at some specific voltage. I found a wall-wart that did the job.
If you’re going to wire parallel relays with your switch machines, that’s all the more reason to use a capacitive discharge (CD) circuit. This simple circuit provides more power to drive multiple devices, and also protects your switch machines when your toggle sticks in the ON position. (Not if it sticks, when it sticks. It will happen.)
I know how to do this with 2 buttons for each direction, but I don’t know how to do this with one button for each direction.
Since you know how to do it with two buttons for each direction, replace the buttons with a Double Pole Double Throw-center off momentary switch. (DPDT - (ON-moem-ON)).
Use the three contacts on one side of the switch to control the turnout, and the three contacts on the other side to control the light indications.
EDIT: The switch should be designated as (DPDT - Momentary-off-momentary)
The OP mentioned that he was using a momentary-contact toggle, so it’s a safe bet that he’s using twin-coil switch machines. So, you can’t use a DPDT to drive both the switch machine and the lights.
The Op said he could do it with two buttons for each direction, so if you used a momentary center off type like I suggested, it could be done. At least that was my intent. A DPDT center off momentary.