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GOLD - Decoder and ABC braking module:
The "dream team" for precise on-the-spot stopping at signals

The new ABC* modules help the GOLD decoders to reveal one of their most important characteristics:

• Precise on-the-spot stopping in front of signals

• Slow approach

• Unimpeded operation in the opposite direction

*Patents Pending

BM1 - the cost-effective solution

BM1    Art. Nr.: 22600

The BM1 has been designed for the simplest and therefore most cost-effective solutions for stopping at a signal. The application is incredibly simple:

If the signal is at "STOP”, the track voltage is directed via the BM1. The BM1 generates an asymmetry in the otherwise symmetrical digital voltage. This asymmetrical signal is detected by the new GOLD series decoders. The result is a gentle braking of the train until it comes to a halt, or optionally with the set braking delay or set braking distance. If the train approaches the signal from the opposite direction, it simply continues because the asymmetry is detected depending on the direction of movement.

If the signal changes to "CLEAR", the BM1 is bridged by the signal switch and the train accelerates at the speed set in the decoder to the DCC instructed speed.

You can build a module like the BM1 yourself by using simple rectifier diodes!

BM2 – the easy and elegant solution

BM2    Art. Nr.: 22610

The BM2 module is available for the more demanding model railroader. Compared to the simple BM1, this module has the following advantages.

• In addition to the signal stop, "Caution" (yellow) is also possible.

• Easy control of the module using light signals and semaphore signals fitted with switches.

• Even push-pull trains with the locomotive at the rear, stop at the right spot.

Depending on the signal setting, you can also use the BM2 to direct locomotives fitted with a GOLD decoders to stop (for signal "Stop"), to pass through (for signal "Clear") or to approach slowly approach (for signal "Caution"). You can set the speed for the slow approach in the locomotive decoder.

The BM2 has two control inputs. Depending on which one is active, the BM2 sends the locomotive equipped with the GOLD decoder the information "STOP or "SLOW APPROACH".

BM3 - block section control

BM3    Art. Nr.: 22620

The BM3 is a BM2 module which has been equipped with block section control. This allows prototypical block section operation. The number of blocks is not restricted as one BM3 is used for every block.

The BM3 has 2 outputs to which signals or other lights can be directly connected. The BMA adapter is required to control double-coil drives (or motors).

A prerequisite for the use of BM1, BM2 and the BM3 block section modules is the locomotive decoder from the GOLD series or another decoder which supports ABC operation.

BMA - Adapter

If you want to connect signals with double-coil (solenoid) drives to the block-section module BM3, you will need this adapter. It is also required when motorised signals are used.

BMA    Art. Nr.: 22630

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A prerequisite for the use of BM1, BM2 and the BM3 block section modules is the locomotive decoder from the GOLD series or another decoder which supports ABC operation.

How ABC works

ABC enables a modeler to stop and hold a locomotive in front of a red signal while allowing trains traveling in the opposite direction to pass without impact.

By using simple building blocks, which supply the brake section before signals with either a symmetrical or asymmetrical DCC signal , the decoder in the locomotive receives the information about the condition of the signal!

In the simplest case the track signal is fed to the brake section before the signal through a BM1 (see illustration 1).

If the signal indicates "STOP", then the BM1 produces an asymmetry in the otherwise symmetrical digital signal.

Illustration 1

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The new decoders of the gold series detect the presence of an asymmetrical signal. The result is a
gentle (either with the adjusted brake delay or the adjusted braking distance) deceleration of the train to a stop. If the train enters the block from the opposite direction, it continues to drive through the block at the DCC defined speed, since asymmetry is recognized related to the train's direction (the
decoder recognizes depending upon the direction of operation, whether asymmetry makes the digital signal "more positive" or "more negative"). When
the signal returns to a normal symmetrical DCC signal (see illustration 2), or the BM1 is bridged by a signal lever, the train accelerated with acceleration rate stored in the decoder.

Illustration 2

Push-pull trains? – no problem!

Would you also like to use "Signal stop" and "Slow approach" for rear-powered trains  (push-pull trains).

To accomplish this, the track in front of the signal needs to be divided into a driving and a braking section.

The length of the driving section must be calculated so that the longest of trains that is to be controlled by this section fits completely within the section. The length of the braking section (as with the BM1) is based on the set braking delay and/or the set braking distance.

Illustration 3

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Driving and brake section are supplied track power through the appropriate outputs of the
BM2.  The control input of the BM2 is connected in parallel with the red bulb of the signal. If the
signal shows "STOP" , then the red lamp of the signal shines and the BM2 is told to stop the train.

When the lead car of the push-pull train reaches the braking section, the BM2 switches the driving and braking section to the asymmetrical DCC signal. As the push-pull train is already located in the driving section at that time, the GOLD decoder recognises the asymmetry and switches to “Stop" or "Slow approach”, depending on the signal setting.

Illustration 4

The BM2 detects when the front of the train reaches the stop section and then feeds the asymmetrical signal into the entire block, thus effecting the entire train (see illustration 5) the locomotive decoder detects the asymmetrical signal and brings the train to a stop after the adjusted braking distance (see illustration 6).

A prerequisite for the process shown here is that the lead coach of the rear-powered train is fitted with a power consumer, e.g.: interior lighting or a function decoder LF100XF (see illustration 4).

Also with the BM2 it is ensured that when operating the train in the section in the
opposite direction no brake applications are applied!

Illustration 5

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What can you do in a block controlled with ABC?

Locomotives remains fully controllable during its stay in a section supplied with an asymmetrical digital
signal :

• Functions can be
  switched

• operations mode programming  (POM) is possible

• the locomotive can be controlled backwards again from the signal!

• switching operations while in a block with a red signal is possible

• no short-circuits develop when bridging a gap between an asymmetrical and a symmetrical DCC signal.

Illustration 6