James Day's remote switch

My chum and I have an unusual quirky layout we take to shows. It is a loose-lay combination of G Scale Trains and 1/24 slot cars which are in the form of a roadway that crosses the tracks at two level crossings. The cars stop for the trains at the crossings.


We had already added some sounds in the form of two mechanical US style crossing bells that are activated by the approaching train.

The layout needed more buildings, so we decided to add a saloon, a church and a barn. As well as lights, each building was going to have a sound module activated by the trains to play Saloon style honky-tonk piano, American Baptist style hymn singing and cattle sounds.

We chose the Model Sounds module as they are excellent value, very effective and can be easily programmed with the sounds of your choice by changing the Micro SD card! Also on a loose lay type layout that already has plenty of wires the battery in each unit saved laying on a smoothed regulated audio quality supply.

Master Blaster unti

As the Model Sounds module is not remotely switchable as supplied this is what we did:

1. Break open the module: insert a series of small screwdrivers between the metal top and the base and prise away until the base comes loose. The base holds the circuit board and this is what you need access to. Be careful not to dislodge or break the plastic control buttons that will tend to float around all the time the unit is open.

Master Blaster unti

2. Find the switch on the circuit board. By using a probe lead you can work out which switch connections you need to tap into to make it switch on and off remotely. Remember the unit takes a second or so to power up so touch and hold the two connections and you will see the blue light come on before the sound starts playing.

In my experience the connections you need to solder to are one in from each end of the five present.

Master Blaster unti

3. Solder carefully and quickly making sure your bare wire ends are pre-tinned and short, so as not to cause short circuits

4. Next you will need to drill a hole in the metal case to let the wires out. It does not matter where you drill it, as long as you make sure you take care not to drill into anything inside the device! The wires need to be brought out of the module through this hole so do this before re-assembly.

Master Blaster unti

5. After you have done all this make sure you test the module to check it still works. To reassemble the unit just carefully squeeze the base back into the main part of the unit, taking care to line up the openings and cut outs in the top for the various switches and ports. It should just fit back together and stay.

6. Next I mounted the unit inside my building using Hot Melt Glue. Taking care to ensure that the ports I needed access to most frequently are the easiest to get to for charging and perhaps changing the Micro SD card every now and again.

Master Blaster unti

Clever stuff, James! Very clearly explained and illustrated too.

See also:

Chris Rigglesford's duck

Boat installation by Brian Rogers

Double servo control by Mick Jefcoate