Jump to content

DC polarity trigger for Kato turnouts


Recommended Posts

I have a need to toggle a turnout based on the polarity of the rails leading into a kato turnout.

This seems like it should be a VERY simple circuit, but I'm having trouble trying to wrap my head around how to trigger only on leading edge of the polarity change.

Is there an existing circuit or product for this.

Note, I'm NOT trying to achieve a reversing loop- this is for single track island platform operation.




Link to post

It will vary from NC through +/- 12v (normal N scale operating range)

Edited by defor
Link to post

A capacitor discharge circuit should work, the harder part is designing the sensing logic. 


The kato turnouts can also be used as spring points, where a train can run through the points even if set against them then spring back to the previous routing.  Would that work for your station?

Link to post

If the spring switch doesn't work, a voltage comparator opamp feeding a capacitor discharge should should work.  Let me know if youd like me to try to come up with a circuit diagram.

  • Thanks 1
Link to post
16 minutes ago, Kiha66 said:

spring back to the previous routing.  Would that work for your station?

not for the design in mind.


I'm actually poking at a second idea that may be even more extensible (I'll have to pen and paper some simulations) using an IR turnout control, but with a polarity based blocker on each end of the platform if no one has any easy answers- cost will skyrocket a bit for all of this however per module...

Edited by defor
Link to post

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Create New...