5 Back & Forth Controllers

Above: Screen capture from AutoControls.org Video #666

(This page modified 6/2/2020)

A. Names and Types

These controls seem to be referred to by the following NAMES:

  • Automatic Back & Forth Controllers
  • Automatic Shuttle
  • Automatic Point-to-Point
  • AutomaticPush-Pull
  • Automatic Reversers

We’ll try to divide these controllers into 3 TYPES:

  1. Analog DC – Simple Versions
  2. Analog DC – Advanced Versions
  3. Digital DCC
  • Analog AC: At least 1 company (Pocono Mountain Lines) made an AC unit that would “pulse” the E unit, but these are no longer made.

Section D below lists a few manufacturers of these units.

B. About the 3 Types:

Analog DC – Simple Versions:

  • The simplest of these units use a simple timer to reverse the polarity every few seconds (usually adjustable from a few seconds to several minutes).
  • Diodes at each end of the track stop the loco from going off the end, but then allow it to go the other direction when the polarity reverses.
  • The AutoControls.org Video #666 (photo at top of page) demonstrates this using a long-since-discontinued PH Hobbies controller.
  • A recently uploaded Youtube video Automatic Reverse Relay for Model Trains by Robert Wilkins gives a good explanation (outstanding narration) of how these work.
    • It appears the video author sells these on ebay.

Analog DC – Advanced Versions:

  • The more sophisticated versions allow intermediate stops, and/or gradual acceleration/deceleration.
  • The Railroad Concepts Stationmaster is one of the more sophisticated units, as it allows for both gradual acceleration/deceleration, plus intermediate stops.

Digital DCC:

  • This can be accomplished using an NCE DCC System plus an NCE “Mini-Panel” to do the controlling.
  • Several AutoControls.org videos show this being done in HO, S, O, and Largescale.
  • AutoControls.org Video #824 shows 2 trains on the same track being controlled point-to-point; click here-1 to view the part of the video that demos the O gauge trains, and click here-2 to view the part of the video that demos the S ga. trains.
  • There is also a method using Lenz decoders and diodes to do automatic reversing. I don’t think this is used too much.

C. Related Articles

D. Companies Making Analog DC Controllers:

(Battery) G Scale Graphics:



Dallee Electronics:


Railroad Concepts:

Robert Wilkins:

Warrior Run Loco Works

  • Warrior Run markets a simple, inexpensive unit.
  • The reverser is not shown on their website; you need to call them.