Lionel uncoupling track

Also, is it advised to use auxiliary power?  This will be used on a simple and temporary Christmas layout.

A single pole momentary push button is all you need. You connect it with a female .110 spade connectors to the connectors highlighted in the picture below:

To prevent accidental lengthened engagement, one may consider adding a PTC Resetable Fuse in series with the button.

@bmoran4 posted:

A single pole momentary push button is all you need. You connect it with a female .110 spade connectors to the connectors highlighted in the picture below:

To prevent accidental lengthened engagement, one may consider adding a PTC Resetable Fuse in series with the button.

Great illustration, I think that I need to say it.

Thanks for posting!

@bmoran4 posted:

To prevent accidental lengthened engagement, one may consider adding a PTC Resetable Fuse in series with the button.

Good suggestion on the PTC to help prevent overheating and melting the coil in the uncoupler.

Since Digi-Key is currently Out of Stock on this PTC, the same part (link here) Bourns MF-050 PTC is available at Newark.

@Don Baird posted:

Also, is it advised to use auxiliary power?  This will be used on a simple and temporary Christmas layout.

Lionel recommends providing 10-12 volts AC to these devices, so an Aux power source set to this voltage would be best.  If you do use track power at up to 18 volts, then the length of time the control button can be held before damaging the uncoupler is less.  In which case the aforementioned PTC fuse becomes even more of a good idea.  The fuse can be wired inline (series) with the either the Aux hot wire to the uncoupler or in series with either of the 2 wires going to the switch.