Track Wiring

[cacole]

Sure it's possible -- I wired the Cochise & Western Model Railroad club's 20x40 foot HO-scale layout so we could run either way. For DC block control, we use the Cooler Crawler throttle system that was developed by TrackTronics, with two hand-held controllers at each of six control panels around the layout. To switch over to DCC operation, a two-position rotary switch on each control panel is changed to the DCC position, and hand-held DCC controllers plugged into RJ-45 LAN jacks around the layout are used. The rotary switch is installed between the DCC and Cooler Crawler throttle outputs and the track wiring. The control panels have the usual block control toggle switches to turn sidings on and off during DC operation, or they can all be left on when running DCC.

[SteelMonsters]

An inductor chokes out AC current to an extent, and allows DC current to pass. A capacitor of the proper value will stop DC, but will allow AC to pass. The values of inductace and capacitance need to at the right levels or they won't protect the power supply or in DCC's case, could render the singal useless.

Ether supply will have tolerances of the amount of current from the other power source that it can take. I don't know about mixing DC and DCC it terms of tolerances. But I'm sure there are products that can prevent damage.

[BR60103]

At a DCC clinic at the NMRA convention last year, this was mentioned. There is, apparently, a device to protect your DC supply from the DCC. I don't know much more than this, or if it's even widely available.
There was discussion about using car light bulbs, but they might not act quickly enough.

[IRONROOSTER]

QUOTE: Originally posted by SteelMonsters



If you do anything other than just one switch to your whole layout, such as two switches controling two blocks when there is a potential to run a loco over a gap then you have the possiblilty that the DC and DCC will short. If you have a dead section between DC and DCC track, if a loco is over one gap and another is over the other gap then they will short together.

Could you use diodes or some other device to avoid the backfeed problem? I would love to be able to block switch beteen dc and dcc even if it means some extra work/devices. But I won't if I can't do it safely.
Thanks
Paul

[SteelMonsters]

The person that posted this thread didn't give a clear discription of what they wanted which leads to assumptions.

If you use both with dual pole dual throw (DPDT) switch or relay to the whole layout then you effectivly sperate the DC and DCC.
http://www.jameco.com/cgi-bin/ncommerce3/ProductDisplay?prmenbr=91&prrfnbr=3716&cgrfnbr=717&ctgys=503;523;717;

That DPDT switch has 6 pins. There are three rows of two pins. The two outer rows are the contacts and the middle row are common. To number the pins 1-6 left to right, top to bottom.
1-2-3
4-5-6
Labled with (R) = right, (L) = left
DCC(L) - Track(L) - DC(L)
DCC(R) - Track(R) - DC(R)

With the switch facing one way, 2 and 3 are shorted together as well as 5 and 6. The other way is the opposite with 1 and 2 as well as 4 and 5. Simply connect DC to one side, DCC to the other side, and the track to the middle. Flip the switch one way and you get DC, the other way gives DCC. Just make sure the switch contact rating is higher than either the DC or DCC.

If you do anything other than just one switch to your whole layout, such as two switches controling two blocks when there is a potential to run a loco over a gap then you have the possiblilty that the DC and DCC will short. If you have a dead section between DC and DCC track, if a loco is over one gap and another is over the other gap then they will short together.

[bcammack]

Everybody who is saying "Don't Do It!" apparently didn't read the initial post. The question was "Either/Or" not "Can I run DCC AND DC trains simultaneously on the layout with Block and Cab wiring?"

If you use the concept of two cabs and even one "block" so that you can switch between a traditional DC power pack and a DCC setup, there is no issue of concern. If you wanted to get slightly fancy and have your mainline as one block and your yard as another and let your DC trains run the mainline, staying out of the yard, and do DCC switching simultaneously it is relatively safe.

The issues raised about attempting traditional block and cab operation with DCC and DC are quite valid, but using the wiring in a thoughtful and intelligent fashion is quite reasonable and applicable to satisfy the poster's needs. As I recall, there was a recent article in some MRR magazine how a club had done similar to allow their non-DCC members the run of the club layout using simple relays.

Merry Christmas

[SteelMonsters]

If you have two blocks, one with DC the other with DCC and you run a loco over the gap, it will backfeed the two power sources. If that happens the DCC booster will be toast and possibly the DC power supply. It's better to convert to DCC by taking locos out of service untill you can put decoders in them.

The more you understand the concepts of electricity behind DC and DCC wiring, the less chance you have of damaging equipment. The biggest concern is backfeeding DC into a DCC booster. Short DC or DCC, the power supply comes back, short both of them together and the smoke will rise.

If you go with both, you should think about every possible way that DCC and DC will short together and prevent it. Having two completely seperate track layouts is a failsafe way to do it.

[bcammack]

There are innumerable diagrams available on the internet and there are books published by our illustrious hosts on the subject. Block-and-Cab wiring is perfectly suited for what you propose. DCC and a DC source need to be no more or less isolated than two individual DC sources. For $25 or less you can buy both the "Wiring for Beginners" and the "Easy DCC" books and have all you need for information at your fingertips.

[Jacktal]

I call this "looking for trouble" big time.It can be done but only by a very knowledgeable technician who would design some failsafe measures through the use of separating switches,relays and so on,and even then the whole wiring job would be a nightmare to troubleshoot for even its designer.

However,you could have DC powered track(s) dedicated to the use of older equipment you don't want(or can't) upgrade to DCC and at the same time have a part of your layout wired for DCC.The two systems would then share only the workbench/scenery but could in no way be linked together,either by wiring or turnouts.

[BR60103]

There is an extra consideration. If there is the possibility that you could connect the DC and DCC together (by running a train between two blocks that are set differently), you could ruin your DC power supply, and possibly the DCC. There is some sort of device that you need to connect between your DC supplies and the track to catch this.

[nfmisso]

JT;

Yes. You would wire it for conventional cab control, and just have the DCC system as one of the cabs. You would have the expense of all the block control switches.

Nigel

[CP5170]

To run the newer DCC engines, you must install a DCC system for your layout. If you do that, you can run one older style engine on the system. You could run more but they all will respond to the "00" address and that could be disasterous.

To run more than one older style engine requires that you wire your layout in such a manner that you can have more than one throttle ( referred to as blocking ).

It would not make sense to me, to wire your layout for both systems, when a DCC wired system will do everything. In addition it would be a wiring nightmare.

Hope this helps...Ken

[Anonymous]

I'm new to model railroading and am wondering if it is possible to wire a layout in 2 different was. 1 being so I can run older style engines and the 2nd is so I could switch over and run the newer DCC style engines. Is there such a wiring scheme out there ??
Thanks JT