Will just one bus do ?

[3 link]

Sorry if this has been asked before, but DCC is very new to me.

 

 I have a fiddle yard 4 tracks wide terminating at each end into single track ( see photo ),

 

 

do I just use the one bus wires to feed all the 4 tracks and just stretch the droppers across to the middle to join the bus ? And have the bus wires running down the middle of the boards?  Sorry if it is obvious but it is not to me.

 

Cheers,

 

Martyn.

[Grovenor]

That will do the job.

Keith

[Brian]

Hi

Yes just two wires make up a DCC bus pair for track and accessory decoder data and power etc.. Thev two wires being of a suitable wire size or from two copper self adheasive tapes.

The wires for the bus pair ideally need to be a minimum of 32/0.2mm or 1.0mm² solid wire or a larger wire size. Having the wire of a larger size won't hurt, it's just a little bit more difficult to instal initially. Opt for flexible wire if your layout is to be portable.

 

Dropper wires of a smaller wire size connect the bus wire to the rails. Normally the dropper is soldered to the rails underside before track laying commences. But if your track is already laid you can solder the dropper wires to the rails outer web area.

Connections at the bus end can be by soldering, the use of terminal blocks or even suit case connectors but here you must ensure the correct size of connect is used for the wire size. Too small and they will cut through the wire, too large and they will be loose and make a poor connection. I don't recommend them for those reasons, soldering is always best. Try to keep all dropper wires as short as possible rail to bus wire. Also if possible obtain the same insulation colours for the droppers as the two bus wires are.

 

If you opt for copper self adhesive tape (a method once recommended by ZTC) you of course can't twist them! But I have seen tapes fixed to the facia side of the layout and the droppers passing through small holes in the facia and then soldered to the tape. It can also be fixed to the top or undersides of the baseboard. The use of tape is ok but it's not one of my preferred methods. Copper insulated bus wires are IMO the best option.

 

You don't have to twist or keep apart the bus pair of wires on small layouts, it wont matter if they are not twisted or kept apart. After all the rails are 9mm apart for N gauge and 16.5mm apart for OO and they aren't twisted!

But it is considered good paratice to either twist the bus pair of wires or keep them at least 2 inches apart.

 

If you look at my DCC pages you should see the basic idea..... http://www.brian-lambert.co.uk/DCC.html

 

 

14/08/14 @ 19:59 edit of post to correct typo.

[3 link]

Thank you so much Guy's,

 

Being so many quick responses means I have time now to put it in practice.

 

Brian, I have your website bookmarked but I could not find this exact sort of advice, but thanks for the help. I have already spent a while on your site over the last couple of days and it has been very useful, and I think the penny has finally dropped ( or will be soon ).

 

All the best,

 

Martyn.

[shibushe]

Martyn. Have used copper Tape from the start, its mounted on the front 2x1 board support. Its about an inch apart.

This bus is an open ended U shape.

One thing a  bought copper tape. It takes solder very easily so don't be to generous with the solder.

[Crosland]

As parallel conductors are brought closer together, the capacitance increases and the inductance decreases. Thus, twisting the bus reduces the inductance. It also minimises emitted radio frequency interference.

 

Andrew

[BR60103]

One consideration:

If you use the same bus for track feed and point motors, running into a point set the wrong way may shut down the whole layout including point control so that you can't just change the point and back out or continue.

If you use some other point control method it won't matter.

[RFS]

One consideration:

If you use the same bus for track feed and point motors, running into a point set the wrong way may shut down the whole layout including point control so that you can't just change the point and back out or continue.

If you use some other point control method it won't matter.

 

I use a separate pair of wires for track feed and accessories (point motors only).  The track feed passes through a PSX-1 circuit breaker, the accessories bus does not.   Thus, if a short occurs due to running into a point the wrong way, I can correct my mistake.

 

Of course this is only necessary if your point motors are DCC-controlled.

[melmerby]

I use a separate pair of wires for track feed and accessories (point motors only).  The track feed passes through a PSX-1 circuit breaker, the accessories bus does not.   Thus, if a short occurs due to running into a point the wrong way, I can correct my mistake.

 

Of course this is only necessary if your point motors are DCC-controlled.

I do the same with an NCE EB1

 

Keith