I have a number of the Lionel sound boxcars, my latest purchase was the UP "Flat spot" FreightSounds PS-1 Boxcar #125404. One thing that always annoyed about these is the manual control aspect of everything, you can't change their configuration while they're running.
Time to fix that.
Some folks have doubtless seen my postings in the The Universal Wireless Remote Control Topic thread. I thought it would be useful to take one of these units and apply it to a practical application. For this task, I figured the 4-channel relay receiver would be a good fit. There were four things I wanted to control and four channels on the receiver, a perfect match!
The object of the exercise is to control the following items.
- Power on/off to the sound board
- Volume step-down from volume pot setting
- On/off control of the two configuration switches
That accounts for all four channels of the receiver.
Below is a shot of the completed installation with the doors open. I positioned the receiver in the doorway so I could access the configuration button in case I wanted to reprogram the receiver module.
Although it's not necessary, I actually made a little wiring harness so that I didn't have to chop any of the existing wiring in the car. I know some folks might like this option, so I figured I'd do the first one with that option.
The wiring harness below goes between the power and speaker connections to the sound board. The speaker connection has a 27 ohm resistor in series with the speaker, and the relay control can short that out for full volume to the speaker. The power connection just routes the power through the relay channel to provide control of the power to the board. Power for the remote control receiver, obviously, is routed directly from the track pickups.
One little surprise came up there that was addressed later. Turns out the sound board has quite a large inrush current to charge it's power supply capacitors. To address that, I later added an inrush limiter to the power lead, it's visible in a later picture sticking out of the wire harness.
Here's the complete wire harness plugged into the the remote control board, the two pairs of wires hanging out are connected in parallel with the two configuration switches. I just soldered these two pairs of wire in parallel with the existing connections to the configuration switches.
Obviously, in order to have full remote control, you have to set the configuration switches to their OFF position. This allows the remote receiver to control the state of the switches.
Here's the chassis with everything mounted and ready for the shell to go back on. Yes, I added my YLB to the car to provide protection for the audio. Note for setting the switches that the closed positions are in opposite directions.
The configuration switches act immediately on the audio stream, so it's not necessary to cycle power to see the effect of the switch changes, you can toggle them on the fly and immediately hear the change in the audio stream.
The reason I had to control power was these cars don't actually have an "off" position for the output sounds, any setting of the two switches still results in audio output.
The 4-button keyfob provides the remote interface to control the car.