The diagram below suggest how the soundcards can be installed in ride on locomotives.

When used in 5 inch and 7¼ inch ride on railways there is a lot of environmental noise. The one watt output of the soundcard is not sufficient for these environments and an external amplifier needs to be used. The wiring diagram below shows how the soundcard can be interfaced to a commercial stereo amplifier in a loco powered by a 12 V battery

A 24v battery powered loco will require a 24v to 12v DC converter such as a Kemo M038. Note that the soundcard can handle a maximum of 24 volts DC. A battery which is labelled as 24 volts will typically output 28 volts when fully charged and will therefore damage the soundcard if connected directly.

For most locos a 12v DC, 2x15 watt amplifier is suitable. Other amplifiers may require the 100 ohm resistor to be changed. If the output volume is too low then raise the value of the 100 ohm resistor.

A single speaker can be used on the right output or two speakers on the left and right outputs.

Any of the five functions can be used by means of a pushbutton between the function terminal and ground. The sound functions available on the diesel soundcard are horn, bell, guard’s whistle, airbrake release, turbocharger and engine stop/start.

The diagram alongside shows a typical installation in 24v locomotive. The 10K resistors keep the motor voltage at the soundcard below 24v.