hi everyone… a problem on the bus line,i bought the new book on electric wiring for for train layouts the second addition from classic toy trains… i have a 8x12 layout and im still confused on the bus line. is it from the transformer back to the transformer or is it one straight line of a bus. i got the common/black down no problem there,im talking the power/red center,does that go back to the transformer to or not,thats what im confused about,and another question is i got SPDT switches that have 3 metal tabs on the bottom,can i make 1 positive/red center and the other 2 ground,i confused there to,thats a second attemped for my siding… please help its a all new track plan and my son just got a MTH SANTA FE PS3 F3 ABA UNIT i want it to go smooth on this layout thanks chad from pittsburgh pa.
Using wire that can safely carry the maximum current that your transformer can put out, connect the transformer common to the outside rails generally. Connect the center rail of each track block to the center terminal of one SPDT switch. Connect each of the outer terminals of each SPDT switch to one of the variable-voltage terminals of the transformer.
When the switch corresponding to a block is in one position, the block will be controled by one transformer control. When that switch is in the other position, the block will be controlled by the other control. If you use center-off switches (SPDT-CO), the block will be unpowered when the switch is in the center position.
If you post the transformer model, we may be able to tell you which terminal is common and which are variable, as well as what gauge wire to use. Note that a transformer puts out alternating current, so there is no positive nor negative.
The power bus line does not go back to the transformer, just as the common does not go back. As Bob posted, connect the center terminal of the SPDT switch to the power wire, and one of the other tabs to the center rail connection of a lockon. If you connect as you posted, you will short out the transformer when you throw the switch to any position.
Larry
“Connect the center rail of each track block to the center terminal of one SPDT switch.”