DCC track bus

[Georgep]

I have a 3 board HO scale layout that is running Digitrax DCC. I have one Digitrax Zepher control station. The railroad 4'x8' boards are set up in a u-shape pattern. One 4'x8' board is at the end of the middle board, and the other is mounted at the side of the middle board. Thus a u-shape. Anyway the point is that if you put a track bus around the edges of the layout on both sides, you would end up with a lot of wire. If you did it that way, you would also be a long way from the control station if you  went from start to finish on the perimeter of the boards. 

My Question is, can I start from the contol station and hook 2 sets of bus wire and go half to one side and half to the other side? Two bus wires will go to one side of the layout and two bus wires will go to the other side. But they will both be connected to the same control station. I think that the end of my bus is very weak and does not have much power to the engines. I am able to run more than one engine around the layout and I do have many places that I have run feeders to the bus wires all around the layout. 

I would rather not have to change the bus wires, but I am afraid that the way I have it now is possibly making programming difficult. I do have a separate programming track on the layout,but I may need to do some programming on the main.

[selector]

Georgep

...

My Question is, can I start from the contol station and hook 2 sets of bus wire and go half to one side and half to the other side? ...

Yes, a T setup is what I use, and so do most of us who want to centrally locate their command station.  Feeder wires of a considerably smaller gauge are then joined at intervals to the bus wires and their other ends meet the rails where needed.

A great many of us use household wall outlet 14 gauge solid wire for the bus, and we use doorbell or similar gauge wire for the feeders.  I use the 22 gauge wires clad in yellow, red, green, and black insulation found at most builder stores.  It comes tightly wrapped in flexible white insulation that must be stripped off in order to get at the smaller wires.

If your bus is a larger gauge and doesn't run much more than about 20' in either direction, there's no reason in the world you should have poor shorts detection in your base station and poor voltage at those extremes.  Something else is amiss, maybe a faulty power source.

[rrinker]

A T in the bus is perfectly fine. In fact, it's the best way to get the most area covered with the shortest bus run. 

Let's picture a simple 4x8. If you put the system unit at one end, you have an 8 foot bus run to the opposite end. Not a problem, actually, if you used decent enough wire, for a Zephyr #14 would be plenty. 

But say you now placed the Zephyr in the middle of the 8 foot side. Now you still have an 8 foot run of wire going from one end to the other, but since the system connects in the middle, electrically what you have is a maximum of 4 feet from the system to the far end. Still covers the same amount of track, but worst case for the electrons is 4 feet out and 4 feet back, vs 8 feet out and 8 feet back with the system at one edge.

                                   --Randy

 

[UNCLEBUTCH]

I had a setup like yours,2X8 center,2X10 on ends=U.  As per advice gotten here, ran bus from C.S. located in center,in a T. worked fine.

Note; I used 12ga.for bus,cause thats what I had,found it way to stiff to work with.I'm rebuilding as we speak and plan to buy 14ga. for bus

Note; Before I ran the 12ga bus,all I had was,22ga feeders pigtailed together with a 22ga jumper to  another bunch, to another bunch ect.THe layout worked fine,ran 3 units,passed the quarter test, but looked like a birdnest.

Could be you have a issue/bad connection somewhere?

[mbinsewi]

Georgep

My Question is, can I start from the contol station and hook 2 sets of bus wire and go half to one side and half to the other side?

Yes, a "T" configuration is fine, as pointed out by others.  Mine is this way.

Georgep

I would rather not have to change the bus wires, but I am afraid that the way I have it now is possibly making programming difficult. I do have a separate programming track on the layout,but I may need to do some programming on the main.

So, which way do you have it now?  And why do you think it is possibly making programing difficult?

Programing on the main is OK, just make sure you have NO other locos on the track, or they will ALL be reprogramed.

Mike.

 

[Georgep]

mbinsewi

 

Georgep

My Question is, can I start from the contol station and hook 2 sets of bus wire and go half to one side and half to the other side?

 

 

Yes, a "T" configuration is fine, as pointed out by others.  Mine is this way.

 

 

Georgep

I would rather not have to change the bus wires, but I am afraid that the way I have it now is possibly making programming difficult. I do have a separate programming track on the layout,but I may need to do some programming on the main.

 

 

So, which way do you have it now?  And why do you think it is possibly making programing difficult?

Programing on the main is OK, just make sure you have NO other locos on the track, or they will ALL be reprogramed.

Mike.

 

DCC track bus

 I have one Zepher, three boards, with one track bus running around the entire outside perimeter of all boards and dead ends before the beginning, and feeders at maybe 4' intervals with one track bus connection to the Zepher. At one point, all loco's slow a small amount at one point on the opposite side of the board, but it is noticeable. I have read the track voltage which is reading 6.81v but I do not know if I have the right settings on the test device. Not familiar with electronics. I do not want to "blow out" my Zepher hence the asking of the question about connection of two track bus's on two sides. I am thinking that I can run the two track bus wires (I think the track bus is 14 or 16 gauge) for each of two track busses down the middle of all boards and split them one bus on left side and one bus on right side. This would make the bus more efficient and save some wire too. Right? By the way, the track joints are not soldered. I know of only one that has given me problems before. So that is another thing I will probably have to do.

The programming track seems to be ok, except that some loco's do not program and some do. Mostly the Bachmann locos do not. I have tried to speed match two DCC Bachmanns, and without a speedometer, I cannot see if the speed is changing or not. But it does not look like it. I have tried to change the speed steps to 14 because the instructions say that it can use 28 speed steps, but 28/128 speed steps is what I get or 14 if I choose it 14 step. The decoders for the Bachmanns only have one setting (start voltage) and none for mid an other so I do not know how to get where I need to go. I just done't see any changes in the engine speeds.

[DigitalGriffin]

I did a little math.  If you made one continous loop you are looking about 50 feet of 16 AWG bus wire.  (give or take) you would get about a 8.5% drop.  So a 14V DCC source would look like 12.8V if you run a full 3 amps.  At 1 amp you loose .4 Volts for a total of 13.6V DCC.

Now if you stuck your command station in the middle and ran the bus down the middle of each table with feeders reaching in. you are looking at roughly 14 feet in each direction.  That will get you 13.66 V @ 3amps or 13.89V @ 1 amp.  Plus you save yourself a lot of wire.  (Using a 2 foot 22AWG feeder will result in < .1V drop @ 1 amp)  Just be sure to use a good amount of feeders (every 3 feet or so)