Track Bus on a oval with a yard with ten tracks.

[Canadian Big Boy]

1. What do you do with the ends of the track bus when you have gone around your layout and are back at the beginning? Does it need to be plugged in somewhere?

2. For the yard, can I run track feeders to the ten tracks off the main bus, or do I have to splice into the main bus with a tee and run another bus under the yard?

Thanks, Sheldon

[richhotrain]

For most layouts, you can just leave the ends of the bus wires unattached.

You can just run feeders from the yard tracks to the main bus wires, although most layouts just align the bus wires to follow the main line so the feeders from the yard tracks won't have to be very long.

Rich

[tstage]

Sheldon,

1. Just let your power bus dead end.  You don't need to close the loop.
2. I would run a tee off your main power bus then run your track feeders off the tee.  If the tee runs down the middle of your yard, the feeders will be shorter that way.

Tom

[BroadwayLion]

Are you running DC or DCC? LION cannot tell you about DCC although him thinks that for the track bus this is irrelevant.

On computers of old, the had a setups that required either a loop or some sort of termination at the end of the line. With the loop, each segment was actually terminated at each node. For computers that were on an old coaxial cable, there had to be a terminator at the end of the line, otherwise the data would spill out the end of the wire and make a puddle on the floor. (Well maybe it was not exactly like that but the idea is correct, and actually the same is true if you are old enough to remember the old roof top TV antennas: you could not have a blind run to a place that had no TV set otherwise the signal would run down that and then come back again painting ghosts on your TV screen.  So complicated.

No DC is not all that complicated: it is just electricity, and there is no SIGNAL on the circuit. Electrons are clear, and if they spill out the end of the wire, you will never notice it. Look at your wall plug, it does not care if a lamp is plugged in or not. It is the same with your train bus. No, do not connect it back to itself. For the yard you can branch off of it like a tree, or you can bring each wire back to the bus. The LION actually wires his yards through the Tortoise switch machines, so that a track only is powered when it is aligned for use, otherwise it is turned off. So the whole yard ladder has only one connection to the bus and that at the first switch machine off of the main, the rest just daisy chain off of the switch machines.

I suspect that the Track Bus for DCC is the same, and does not need a baud at the end of the end of the run to protect the signals from wandering off into space and making feedback on the system. If you use a LOCONET, then yes, I do believe that the LocoNet does require termination somewhere since that is a data circuit. and you do not want your bytes to get bit.

ROAR

[betamax]

Don't make a loop with the bus.

As for the yard, just split the bus line coming from the booster, one for the mainline, one for the yard.  That will make it easier later if you decide to incorporate another booster for the yard or a power management device.

With the yard, you can just run the bus perpendicular to the track and tap off the feeders from there for each track.

[aj1s]

How big is the layout? 

If it is small (say, 4 x 8 or so), it really won't matter whether you connect the tail end of the bus back to the booster or not. On larger layouts it does matter; don't connect the bus in a loop. Furthermore, if the oval is large (room size), then it would be better to break the bus (and double-gap the rails) on the far side of the oval from the booster, and connect both (original) ends of the loop to the booster. This halves the distance, and voltage drop, from the booster to the electrically farthest point.

I would make a separate yard bus, teed off from the main bus for two reasons. It keeps your feeders shorter, and it makes it easier to set the yard up as its own district, with separate circuit breakers. This would keep a short in the yard (from a derailment or a miss-thrown switch) from shutting down the main loop. All you would have to do it cut the yard bus free from the main bus, and wire it to a separate circuit breaker.

Hope this helps,

Andy

[Canadian Big Boy]

The layout is ruffly 11'x24'. I'm planning on having two districts, the main and a small siding run by one 5 amp booster, and the yard, roundhouse, and transfer table on another 5 amp booster.

Thanks for the info Andy.

[Canadian Big Boy]

Thanks Rich.

[Canadian Big Boy]

Thanks for the info Tom.