Power Bus Wiring
As mentioned at the close of my last post, I’d ordered some wire for the power bus from an ebay supplier. Well, it arrived and it’s perfect!
I ordered 2½m each of red and black 1.5mm 21A 16AWG 12v Car Loom Wire from ebay seller CCS-UK which came in a nice little packet shoved through the letter box.
Using a much larger cable for your power bus and attaching your dropper wires to it at regular intervals reduces voltage drop. The Nickel Silver used in most model railway track has almost 20 times more resistance than the copper in wire.
Similarly, smaller gauge wire is more resistant than larger. Resistance is electrical energy lost and, as the First Law of Thermodynamics states, energy can neither be created nor destroyed, only transformed. As such, resistance typically generates heat.
None of this is going to be a critical problem on this layout but I’m using it to practice technique, and it’s as well to follow best practice at the same time. On a large layout, using a power bus negates the resistance in the nickel silver, as well as the mechanical joints of the rail joiners, ensuring that as much power gets to the far ends of the track as possible.
It is of course also possible to plug in booster power packs but, if you follow the above practice, that should never be necessary.