Signal Blocks (Analogue)

Latest update: 19 May 2016

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Signal Control Basics:

If you haven’t already, read this page first: Signal Control (Analogue).


Manual Signal Block:

A manual signal block is the easiest way to implement a signal into your track layout. You can create a signal block system by using a supplementary switch attached to the electric signal drive. We need the following components:

  • Supplementary Switch – A supplementary switch (also called ‘relay contact’ or ‘DPDT switch’) can be connected to electric switch and signal drives, and is used in more complex train control circuits. Available from LGB (#12070) and PIKO G (#35265).
  • Track Isolators – One of the rails needs to be isolated to create a track block. To do this, we need some track isolating clamps or isolated track sections.

Want to know more about these components? Who sells them? Specifications? Manuals? Availability and prices? Read these pages: LGB ‘EPL’ Components & Alternatives & Track Isolators.

The wiring diagram below shows an example where two LGB #10153 isolated track sections are used. An LGB #12070 supplementary switch is attacted to the electric signal drive. When the signal stays ‘Stop’, power to the isolated track block is turned off and the train will not move. When the signal changes to ‘Go’ (by user input on the control box), power to the isolated track block is turned on and the train will start moving. The red arrow indicates the direction of movement.

LGB EPL Signal Control Blocks Circuits

A slightly more detailed view of the connections. Note: on the diagram below, the power supply connections on the side of the control box should not be there, they should be connected to the proper ‘3’/’4′ terminals of the control box (see diagram above).

LGB EPL Signal Control Blocks Circuits

The example above shows just a single track, of course you can extend your layout with more signal tracks by just repeating the process for a second signal.

LGB EPL Signal Control Blocks Circuits


Distant Signal:

The #50910 “distant” signal can be added to almost any signal circuit. The distant signal only functions as a warning to the engineer that a mandatory “home” signal is ahead. So the
#50910 has no train control functions (and no supplementary switch). The circuit is simple. Connect the orange and white terminals on the 50910 to the orange and white terminals on the “home” signal. Now, the distant and home signals work together at the same time with the same control signals from the control box.

LGB EPL Signal Control Blocks Circuits


Semi-Automatic Signal Block:

On a real railroad, the manual signal block would be considered dangerous. Why? Because it relies on fallible humans to set the signal properly.  The EPL system offers an easy, but partial, solution. We need extra components:

  • Track Contact – Track contacts are placed between the rails, and can detect trains to create automated circuits. Available from LGB (#17100) and PIKO.
  • Loco Magnet – Each locomotive needs to be equipped with a magnet on the bottom, so they can be detected by the track contact. Available from LGB and PIKO.

Want to know more about these components? Who sells them? Specifications? Manuals? Availability and prices? Read this page: LGB ‘EPL’ Components & Alternatives.

Install a track contract in the track after the exit of the signal block. Once a train passes through the block, it crosses over the track contact and automatically switches the signal back to “Stop” (Hp0). That prevents another train from accidently passing through the block until the operator manually sets the signal to “Go” (Hp1) using the control box.

LGB EPL Signal Control Blocks Circuits


Automatic Signal Blocks:

Of course, we can make our signal-controlled railway even safer by eliminating the human factor completely. With this fully automatic circuit, you can run two, three or more trains at the same time without any fear of collision.

The number of trains you want to run determines the number of Automatic Signal Blocks you need. You always need one more block than the number of trains you want to run. In this example, we want to run two trains, and so, we need three blocks.

The block circuits are very similar to the Semi-Automatic Signal Block. As before, the circuit uses one 17100 for automatic “Stop” (Hp0) control. However, there is no 51750 for manual “Go” (Hp1) control. Instead, there is an additional 17100.

Here’s the trick: The “Stop” 17100 is installed after the exit of the block, just like before, but the “Go” 17100 is installed near the entrance of the block two blocks ahead.

When a train leaves a block, it disconnects power from the block immediately behind it. When that train reaches the entrance of the next block, it connects power to the block two blocks ahead, releasing the train stopped in that block. This arrangement keeps the trains moving from block to block, with one “Stop” block between them at all times.

This circuit is relatively simple to build, impressive to watch and easy to operate. The only special consideration is that the distances between the blocks should be at least one train length.

LGB EPL Signal Control Blocks Circuits

The full diagram:

LGB EPL Signal Control Blocks Circuits