S Gauge, 1-Track Automatic Block

Using RR-Concepts Switching Interface Module

Project 142,   forwarding link is   track2.com/info/142

S *m*e*n*u | 142

* Project 142 *

 Video #658

A Introduction
 (this page)

s *m*e*n*u-09L | S Plans-IAC
* S Plans *

1 AutoControls Home

7 S-Plans Index
 (in Museum)

8 Special Parts
10 List of Videos

 1-trk (Proj 142)
 2-trk (Proj 241)
  (AF trk trips)
 2-trk (Proj 242)
(reed switches)
1-trk computer-


Wiring Diagram [below]




This  S gauge automatic block can control 2 trains on the same track.  The block uses a RR Concepts (rr-concepts.com) 'Switching Interface Module' (aka SIM) to operate the current-switching to do the stopping and starting.

The automatic block keeps the 2 trains "spaced apart" on the loop.  If a faster train starts to overtake a slower train, the block stops the faster train and delays it, until the slower train "regains" the spacing between trains.  Rheostats are used as a crude, but simple and effective method of slowing down the trains as they enter the block, and "cushioning" their start as they start-up to exit the block.

Video #658 -- which is linked from the left menu bar -- probably demonstrates this more clearly than the verbal description.

The below drawing shows the wiring diagram for the 1-track automatic block demonstrated in the AutoControls YouTube Video #658 " S Ga. Auto. Block Using RR Concepts SIM" . This wiring diagram is could probably be improved by adding a 2nd rheostat. Use the diagram for Project 242, 2-track Automatic Switching Block" as a reference for wiring the 2nd rheostat.

More Details

The 'Switching Interface Module' is essentially a DPDT (Double Pole, Double Throw) latching relay, with added screw-connection terminals, plus voltage regulation that allows you to use a range of input voltages to power it; 6 to 20 volts AC, or 6 to 20 volts DC.
The relay can switch any current, AC, DC, or DCC.  This demonstration was done using using two unmodified vintage American Flyer engines with the original AC motors, an S-Helper diesel with a DC motor, and a DCC decoder-equipped American Flyer 283 Pacific.  This demonstration was done using a DC transformer, since all these engines can "happily" operate on DC current. 
Activation of the relay is done using RR-Concepts-supplied magnets and reed switches.  The magnets can be "stuck" to the bottom of an American Flyer car, since they will stick to the car's metal floor.  Note that the magnets I used on the bottom of the American Flyer cars were the RR Concepts magnets they sell for LargeScale.  (They also supply smaller magnets to use with HO trains.)
RR Concepts (operated by a gentleman named Curtis Roeckes in Oceanside CA) has been supplying electronic modules for LargeScale trains since about 1992.

Wiring Diagram for Single-Track Block
As noted, a 2nd rheostat for better speed control is recommended.
[pdf version]

(ref-previous outdated blog page)
This page created Dec 2009, modified 12/13/2009 by (bottom include)
JamesRobertIngram.com , Williamsport Pa, Voice Mail 570-322-7597