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Reply to "Is there an automatic trolly"

1. Simple DC Polarity Reversers:

If you can operate the trolley on DC, and do NOT require an intermediate stop -- then there are a BUNCH of systems that use a gapped section with a diode at each end of the track, and a controller that simply reverses the track polarity using a timer.

  • These are probably the SIMPLEST way to do automatic shuttle operation.
  • When something is not working right, they are relatively easy to troubleshoot, because the track power is ALWAYS on, it just peridically changes polarity.

How They Work:

  • When the trolley reaches the end of the track and crosses the diode section, the DC current cannot propel it any further in the direction it was going.
  • It sits and "waits" until the polarity is reversed, then the diode allows current going the other way to reach the motor, and the trolley starts up in the other direction.

I attempted to do a DEMONSTRATION of this type of unit in this video: .

The below IMAGE shows the LGB loco and the S gauge loco I used, but the gauge doesn't matter -- as long as the loco runs on DC.


I think the Bachman system that 'dkdkrd'  mentioned above, uses this type of system.

These controllers are fairly simple for electronics people to build, and I think you can get the more "homegrown" versions as low as around $30.

The units usually include a knob that controls the time delay between polarity changes, which controls how long the trolley sits at the end before it starts up in the opposite direction.

  • In the above image, the blue box is the controller
  • The black knob on the top of that blue box, controls the time delay.
  • This unit is a no-longer-made PH Hobbies unit, but currently-made units operate pretty much the same way.


Warrior Run Loco Works  located in NE PA, was marketing a "home grown" unit a couple of years ago for around $30. I can't find it on their web site, but they may still produce it.

You can sometimes find these USED reversing controllers at train shows.

  • LGB has been making these units for years.
  • Also Split Jaw made them; they're now out of business, but many used ones seem to be around.


2. More Sophisticated:

If you want a more sophisticated unit, Railroad Concepts makes a "Stationmaster Reverser" unit that does gradual acceleration/deceleration, plus intermediate stops. Details here: .

3. DCC Option:

If you didn't mind using standard NMRA DCC, you could use an NCE DCC "Mini-Panel" Programmable Train Controller to run a unit point-to-point -- with the added BENEFIT that you can have lights and sound ON -- all the while that the trolley is stopped.  (You might have to "lean" on your HO friends, who are probably more familiar with the DCC stuff.)

I did a 2-minute-long video demo of this type of operation using two MTH Proto 3 locos in this video: .

Just pretend those two MTH locos you see in the below IMAGE are trolleys, and hopefully it gives you the idea.



Images (2)
  • scnCap25_56_666
  • scnCap824B-00-06-portable
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