What the DCC diagrams generally show is common rail within a power district - huge difference. Whole layout common rail is NOT the idea for DCC, you need to use optoisolated boosters for one thing. Gapping for detection depends on the system being used. The preferred current transformer types only need one rail gapped per detection section, so it looks alittle like common rail. If you don;t use any sort of downstream circuit breakers, what you end up with is that within the track controlled by one booster, one rail is all connected together, and the other is gapped into however many block detection sections you have. Between boosters, both rails must be gapped. ANd if you do use circuit breakers, generally both rails need to be gapped between sections controlled by different breakers. Now if a given breakler section has, say, 3 detection sections, you have double gaps, two more gaps in one rail, the detection rail, and double gaps at the opposite end.
In words it's way more complex sounding than it is. In fact, substitute the detectors for the Atlas Selector, and of course there's only one 'cab', the DCC booster, and there is the wiring for block detection with DCC.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
rrinker I think rahter than make the two loop blocks the same size, the idea of the simple diagram is to show that the blocks don;t all have to be the same physical size. Yes, for Electrofrog, another gap is needed. But then it is a common rail Atlas design so certain assumptions were probably made.
That was the idea, just to give a new person a simple explanation of how cab control works. I could edit, change and or correct this diagram for the next year and somebody would still find something to change. Of course they could create their own diagram .
Definitely the common rail should have a feeder in every block.
Per common rail, I have used it since the late 80s, never had any issues, same power packs are still in use. No problems ever developed and I think after 25 years they would have.... The Atlas common rail books have been around forever. Homes and cars use a form of common rail.
For signaling I can see where double gaping would be appropriate. Or on a large multi cab / operator / dispatched layout.
Almost all the DCC diagams show what is basically the common rail side, one long buss with multiple feeders. If I were ever to convert, I would add a second buss and attach my block feeders to it and make a new panel. But that is a topic for another thread.
Jim
LION connects the left rail of him to ground about every 6'.
Blocks of LION are between each station. Block A brings a train into the station, block B takes it out. Yard throats are a separate block. LION once had two main line throttles, and a separate throttle for the yards. If the switch was lined for the main, the main controlled, once the main was put to normal, the yard supply was in effect.
LION of course is far more complicated than that, but the idea is the same.
ROAR
The Route of the Broadway Lion The Largest Subway Layout in North Dakota.
Here there be cats. LIONS with CAMERAS
I think rahter than make the two loop blocks the same size, the idea of the simple diagram is to show that the blocks don;t all have to be the same physical size.
Yes, for Electrofrog, another gap is needed. But then it is a common rail Atlas design so certain assumptions were probably made.
I've never been a fan of common rail, even back when everything was DC - I insulated BOTH rails at every block and gave each block feeds for both rails. On anything but a trivial layout, that common side should have more than just one feeder so as to limit voltage drop - with just one common side feed, you are relying on the rail joiners to carry that side of the circuit around the entire layout.
LION is past master of DC Block Control. You may make as many blocks as you require. You can also have as many cabs as you require, but that requires some fancy control work. LION has five gang interlocking switches, him used a gang for each block and a switch each cab. Wiring can be a pita. Much easer with two cabs, then toggle switches will work just fine. There are 3 and four position slide switches that could be used. A rotory switch can be used, but then it would pass through other, possibly active positions, while selecting the one you want to assign the block to. Look at mini "piano-switches" for each block if you have more than two cabs.
The LEFT Rail goes to GROUND. One output from each cab also goes to GROUND, and be sure it *is* grounded otherwise stray voltages will drive you crazy.
It really does not matter which cab output goes to ground, but it would be nice to be uniform. Look at the Piano Switch in the picture (limk above), Tie all of the front pins together and coneect that to the RIGHT rail of the block that it is to control. Now connect the other output from the cabs to the numbered pins toward the rear of the Piano Switch. These switches have no logic, and so it is possible to assign two cabs to the same block, which would not be a good thing. *YOU* have to supply the LOGIC to this switch by shutting off one block before opening another.
Positive power to the block will make the train run forward, negative power to the block will make the train run backwards. The reversing switch on your cab controls that, wiring the cabs uniformly will assure that they all operate the same way.
If you later decide to go with DCC, just put the DCC on the #1 block, and move the whole railroad to that number. You will have to switch the common to the DCC system instead of ground, so the other blocks will not operate.
And that, is that!
Isi3009,
A suggestion: Stay away from common rail wiring. Read books on wiring with both rails insulated, for dual cab wiring, better in the long run, will require just a tad more wiring and DPDT center off toggles. Much easier to convert to DCC down the road if You so choose.
One of three control panels on the layout, this one being 30yrs old. The others have rotary switches in place of toggles, for 3 cab control. All DC layout, but on occasion, I do run DCC/sound.
Take Care!
Frank
Soo Line fan Using Toggle Switches Using Atlas Selectors
Using Toggle Switches
Using Atlas Selectors
If you're going to search the Intenet for instructions, spell "dual" correctly or you'll never find the answer.
I have an old Atlas wiring book, but I think the newer ones are about the same. You can often find them at model rr shows. It is very simple to follow. Of course it uses their products, but you can substitute others if you so desire.
Good luck,
Richard
This is very well documented, since it pretty much goes back to the dawn of model railroading. Just google it, there are dozens of sites with diagrams and explanations.
You need to break the layout up into multiple blocks, and use a double pole double throw switch for each one. The center terminals go to the rails. One side goes to Cab A, the other side to Cab B. Flip the toggles to connect the appropriate blocks to the correct cab, the cab a given block is connected to will control speed and direction in that block.
Our club did this many years ago with common rail and 14 different blocks. one reverse loop using a DPDT switch. needed a dispatcher at the control panel with four different operators.
The loops had to be isolated excerpt for a cross over.
Much easier when we went to DCC but that is not part of your plan.
Rich
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.
Looking for information on daul cab control with dc. Looking to put in a second mainline. How would I run two trains in separate directions on separate tracks using daul cab control with dc .