Northern Tablelands Express approaching Ardglen Tunnel

Northern Tablelands Express approaching Ardglen Tunnel
Click on the above photo to see the Main North Album at Flickr

Thursday, July 4, 2019

Audible Warning for NCE EB1 Circuit Breakers.

Previously I have fitted an audible warning to some of my NCE EB1 Circuit Breakers to let Operators know that when a loco stops running, they have short circuit instead of loss of power, using a Piezo Transducer Module from Jaycar Part No XC-4424, connected to the the EB1, shown below.

With Operators running in both Broadmeadow (lower deck) and Werris Creek (upper deck), where lots of shunting/marshalling trains can be done at the same time, a buzz from either of the EB1's that are located in the same area, it's hard to determine which District is shorted without looking at which EB1 has a flashing LED. This ia a bit hard for a visiting Operator to know where to look. Yes the trains stop when there's a short but with Stay Alive they don't stop straight away. See below.

During a recent Operating Session, Operators asked what's the buzz noise in the Trainroom when running trains and another Operator, while setting up his trains in Gosford, felt he caused a few shorts as others were having trouble with running trains through Gosford. The Gosford EB1 did not have "noise" (Transducer). The easy fix would be to isolate the track used for setting up trains - I'll do that one day.

I wondered about another solution by having an "announcement" when a power district was shorted. I'm into recycling my train stuff even if it's 30 years old. Many years ago a I made a Digital Voice Recorder from the December 1989 Silicon Chip magazine, used with my son's Lego trains.
I found the Board along with a lot of other junk under the layout, I spent an afternoon mucking around with it to see it would work for the "announcement" solution. While it provided 4 announcements, each triggered separately, I was not happy with it.

Since seeing Dave Lowe's Arduino Presention at the 2018 Modelling the Railways of NSW Convention, I bought an Arduino Uno and a Stepper Motor from Jaycar to "try" and motorize  a Turntable from an article I saw in AMRM. Nothing done yet with that project.

Browsing around at Jaycar when I'm there for electronic components, I saw a 10 second Record and Playback Module for the Arduino. I checked the details on-line and thought I'd try one instead of using the kit above, but I did not want to use the Arduino Uno to make my announcements work. I needed one of these Modules to play around with.

Jaycar Record Playback Module XC4605

Shown below attached to an NCE EB1.

The Record Playback Module needs 5.0 Volts D.C. (not 12 V) and I needed to trigger it from the EBI instead of the Arduino so I need to use a Relay but a conventional "coil" type one would create more "circuitry" in my simple logic, so I thought I'd use a Solid State Relay from Jaycar, see:

Jaycar PCB mount Solid State Relay SY4090


The Record and Playback Module comes with a Microphone installed.
Connect an 8 Ohm Speaker.
Provide 5.0 Volts DC and a "triggering mechanism" where both are normally supplied by the Arduino.

I soldered a 5.0 Volt 3 Terminal Regulator to the Capacitor on the EB1. I have since found that the EB1 has a 5.0 Volt Regulator already installed. I'll connect to that in the next EB1 upgrade.
I connected DCC to the EB1.
Press the REC Button while yelling your "announcement", to get the highest volume, numerous times until the "REC" LED extinguished (10 secs).

Pressing the "PLAYE" or "PLAYL" Buttons provided the "Short Circuit in Werris Creek" message.

Triggering the Module.

EB1 (default) Operation:
EB1's LED ON= Power to track. LED Extinguished = Short.
When there is a short. the EB1 disconnects the power to the track for 2 seconds then re-applies the power. If the EB1 still senses a short after 16 milliseconds then power is removed again for 2 seconds. This cycle keeps repeating until the short is rectified. Note the EB1 "settings" can be adjusted, see the Manual.
The Module has to be triggered each time the LED extinguishes.

Connections for the Solid State Relay are:
Pin 1 to the EB1's Terminal Block position 3.
Pin 2 to the EB1's Earth at Pin 8 of the 12F683, the IC adjacent to the Terminal Block.
Pin 5 and 6 to the "PLAYL" Switch. Note: Pins 5 and 6 connection are polarity conscious.

Now we know the the Operator in Werris Creek (upper deck), has to correct his "action" etc.

The Record Playback Module, Solid State Switch and the 5.0 Volt Regulator for the modification cost about $17.00 at Jaycar plus the EB1.

If using sound decoders, don't forget to to program the EB1's CV 135 to 4. For more details see the EB1 Manual or Mark Gurries's page on the EB1 at: Mark Gurries EB1 page.

The completed "announcement" EB1 fitted behind the Fascia at Gosford. The Record and Playback Module is held to the EB1 with a Cable Tie and connected an 8 ohm speaker. The volume is more than loud enough with an old Traino 44 speaker with an easily made enclosure from some 27 mm (o.d.) conduit, 50 mm long.

The 6 Pin Solid State Relay "located" between the two boards, held with two links:
Solid State Relay Pin 1 to the EB1 Circuit Board Terminal Block's Pin 3 and
Solid State Relay Pin 2 to Pin 8 of the the adjacent PIC12F683 chip.
Solid State Relay Pins 5 and 6 (Blue and Yellow wires) are connected "across" the "PAYL" Switch of the Rec Play Module.
The 5.0 Volt 3 Terminal Regulator can be seen on the R/H side, soldered to the EB1's 470 uF Electrolytic Capacitor. Simple and it works.

The announcement of a "short" as a slack Operator runs against an incorrectly set Point in Gosford, see below.

If you want to make some of these "Annoucement EB1s" phone me on 02 9402 8929 for more details. I will take further photos as I make more of these "Annoucement EB1s".
I have made 5 of these Annoucement EB1s, all now using 5 Volts from the EB1 5 Volt Regulator, saving using a separate 5 Volt Regulator.


  1. Well done Marcus, buts is not very forceful of you saying “ short circuit at Gosford” you can do better you should be screaming out in a loud voice ’‘WHO’S THE DILL DOWN AT GOSFORD, YOU FORGOT TO CHANGE THE F..KING POINTS, GO SIT IN THE NAUGHTY CORNER FOR TWO HOURS”

    1. Hi home layout. That would have been me 20 years ago but I have mellowed in my old age.

  2. Name and shame! I like it! Looking forward to my next visit, Marcus! :)

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