Video 668: Z-Stuff DZ-1012v Block Detector Automatically Controls 2 O-Gauge Trains

This page started 11/2018, updated 7/1/2019

This page contains Images and links for Video #668 Z-Stuff DZ-1012 Detector Controls 2 O-Gauge Trains On 1 Mainline”/

1. Links to the 3 Videos:

  • Part 1 – Recommended Method “Delay From the Front“: or
  • Part 2 – Alternate Method “Release From the Rear” using DZ-1011 detector: or
    • Note the last 18 minutes of Pt. 2 reviews some alternate methods of controlling 2 trains on the same track.
  • Part 3 – Alternate Method (better than Part 2) “Release From the Rear” using DZ-1012 detector:  or
    • The DZ-1012 works better than the DZ-1011 because the DZ-1012’s adjustable time delay allows more flexibility in train length.
    • The note underneath Fig. 2C below, shows the 1 wire that has to be moved to change the relay from “normally closed” as used in Pt. 1, to “normally open” as used in Pt. 3.
  • There are MORE links below in Para 5 “More Related Links”.

2. Summary:

  • This video #668 shows a Z-Stuff DZ-1012v Block Signal Detector and DZ-1008 Relay automatically controlling 2 O-Gauge trains on the same track (see below photo).

Two different logic methods are demonstrated:

  • Part 1 of the Video demonstrates the  “Delay From the Front” method — which we think is the most versatile.
    • The train in front uses the “stop block” to delay a train following too closely.
  • Parts 2 & 3 of the video demonstrates the “Release From the Rear” method — which has a similar logic to the “Insulated Rail” method.
    • The front train is “trapped” by the stop block, and depends on the train approaching from the rear to “release” it.

3. Images:

Note: CLICKING ON any of the below images, should open them LARGER.



  • The next 3 images are from Part 1 of the Video — which demonstrates the  “Delay From the Front” method.
  • The last image Figure 3 is from Part 2 of the video — which demonstrates the “Release From the Rear” method.


  • The “Delay From the Front” method is probably the most versatile method.
  • If you make a small test layout, you can easily experiment with both methods.
  • Note you need the DZ-1012v Detector to do the “Delay From the Front” method.
  • The DZ-1011 Detector can be used ONLY for the “Release From the Rear” method.

The above drawing is for “delay from the front” as demonstrated in Pt. 1.


To use the DZ-1012 for “release from rear” operation as demonstrated in Pt. 3 of the video, you need to move just 1 wire — as described below.

  • (Move the white wire going to the track, from Terminal 6 (as shown above) to Terminal 4.  This changes the relay from “Normally Closed” to “Normally Open”.)


5. PART 2 OF THE VIDEO (Alternate Method)

  • The below Figure 3 is from Part 2 of the video, which shows the 2nd logic method, “Release From the Rear“. (Part 3 uses the DZ-1012; see Para. 4 above.)