The Motor's Power Supply And Switch
In order for the train to reverse direction at the end of its 10-foot track, a reversing switch is needed. A power cable with a USB plug is connected to the battery pack at the back end of the train. I wouldn't suggest plugging the USB cable into a motherboard header, though. First, the motor draws more than 500 mA, exceeding the USB 2.0 spec. Secondly, a commuted DC motor feeds all kinds of electrical noise back into the power source, and this could affect audio quality during music playback.
There's a tiny metal bracket on the first and last piece of track, which is responsible for tripping the switch on the bottom of the tender. The polarity of the cable connections is absolutely critical if you want the reversal to work correctly.
Mounting the switch is easy, but it needs to be correctly oriented.
Finally, the motor's on/off switch has to be installed at the back of the tender. It's not positioned ideally; when the locomotive is lifted up, flipping the switch inadvertently is too easy. So, you'll want to make sure to keep the battery pack's switch turned off before transporting the train.
With cables run between the switches and battery pack, it's time to put the locomotive on the tracks for a test run. But what's the point of having a non-working PC moving around? Thus, I decided to replace all of the system's cables (except power, of course) with wireless connections.