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Discussion Starter #1
I am designing a new, somewhat complex, layout. I know I can set it up with DC, and was planning to. I have been reading up on DCC, and know I can probably wire it up with a DCC starter set to run 5-7 trains. Hopefully it would allow me to add on functionality, as I have money to switch over the turnouts, lights and other accessories. It looks like I will be adding various support boards. I am not sure if they belong on the control panel or the layout near the accessory or turnout (or block detector, I think they call it). I will probably be adding DCC logic to pre 2000 engines, as well (only about half a dozen).

I am looking for a decent source of information, that would allow me to pick a decent starter set. With my background in electronics and computers, i would of thought, no problem. What I am seeing, just leaves me with far more questions than answers. The documentation I see, is on a level that is not helping much. Are there best practices for this kind of thing (or a direction that is better than the other)? At this point I am leaning toward NCE or Digitrax (spelling??). From what I hear, all they do is DCC, unlike Bachman or Atlas type companies, where they do their part of Model Railroading well, but their DCC systems may be a bit lacking (not really their focus).
 

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Since you're familiar with electronics, do you have any experience with arduinos? There are a variety of DCC projects out there that you could build yourself to ensure expandability, To begin, take a look at the DCC++ project (also an offshoot that I work with which goes under the name DCC++ESP32 or ESP Command Station) and you'll find a whole community of support. These projects can get you up and running and are compatible with commercial equipment, so you can use off-the-shelf decoders in your locos.

The next thing you'll want to look at is a way to control turnouts. Do a search for Geoff Bunza, who has a number of blogs. SMA20 is a good starting point. His code works with the arduino nano boards and allows you to set up cheap servo motors to control your turnout points.

Finally, sensors. This search will be for Rudy's Model Railway, and he has a variety of projects for railroads. Take a look at his S88 projects, which let you read the state of simple sensors like reed switches or IR LEDs. That data can be fed to a computer and react to the inputs.

Adding DCC to older locos isn't too hard as long as you understand basic electricity. The old motors were usually grounded to the loco chassis, so you need to separate that and make sure there is no crossover between the motor and the wheels picking up track power. You end up with two wires from the wheels (track power), plus two wires from the motor, and these get soldered to the DCC decoder... and there you have your first basic DCC loco.

There's a lot of possibilities once you go DCC, and a ton of knowledge available on this board... you just have to figure out the right questions to ask. :)
 

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I'm not really clear on what is stumping you. For a complex layout, you'll want a power bus, probably at least one or two sub-buses, and perhaps some DCC signal boosters if the power districts supplied by the subs are rather large AND complex in their own right. You want to keep a robust starting voltage from the main system's outputs all the way down the line for short-detection purposes, and to keep engine performance optimal. So, you'll want household wall gauge wire for the main bus, perhaps the same for a sub or two, or down to 14 gauge, and maybe a booster in series to keep the signal and voltage high onward in each case.
The only other boards you'll need might be a circuit breaker or a phase/polarity reverser if you have 'reversing loops' or turning 'wyes'.

Is this the type of information you're looking for?
 

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besides a decoder in each locomotive, a DCC system is composed of 3 parts: a controller you hold in you hand, a command station that one or more controllers communicate with and that generates the DCC signal and one or more boosters that provide power to the track. the command station is often combined with a booster.

a large layout may be broken into power districts, each with a circuit breaker to limit short circuit current that might occur when a loco derails. a single booster may have multiple power districts. (a smaller 5A booster is probably sufficient for your size layout).

reversing sections need auto-reversers that sense a short and quickly reverse polarity in the reversing section that must be isolated

when track is not visible, that section can be electrically isolated and power routed thru a block detector to indicate if something is drawing current thru the block. a loco will certainly draw power as well as lighted passenger cars. freight cars may require wheel resistors (10k).

tortoise switch machines are commonly used to control turnouts, draw as much current as an LED and can be left powered in one of two positions controlled by panel switches or electronically

C/MRI nodes and computer control can be used to minimize wiring but requires custom PC software, configuring JMRI panels, ... there are of course many hobbyist DIYer projects that can support this

smartphone apps can be used to control locomotives using JMRI running on a PC of Rhasperry Pi connected to the DCC system with a USB adapter

ask questions
 

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Discussion Starter #5
Gents,

This is a good start. Being knowledgeable about computers and electronics being what it is, having some documentation that is written above the beginner level is helpful (the simple documentation leaves a few holes, that I would like filled before I start building). I am building this layout with an eye toward being able to move it for the occasional train show. Is it better to have all the electronics with the control panel, or should some boards be mounted, under the table, near the accessory or turnout?
 

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Discussion Starter #7
Greg,

I know the cars and locos would need to have their control boards, on board the car or loco. The location of turnout control boards, and some other support boards I am trying to position, in my design. Some of the electronics (coils to move switches and detection equipment need to be on the layout somewhere). Now the boards that control or read the electronics on the table needs a position, either under the layout table or under the control panel. Am I better off keeping the off table control panel simple (just what the control panel needs to run things), or do I have a electronics panel stashed under the layout, with the necessary wires running back to the control panel?
 

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i think the general answer to your question on a layout of your size is all electronic boards can be mounted on a plywood board somewhere under the table, possibly a leg with wires runnng from them to devices on the layout and the control panel.

also in general, the panel is only as large as needed for switches/buttons controlled by the operator and is not large enough for all the electronics


switch machines need to be located under/near the turnouts. if they are controlled push-buttons or toggle switches, those switches need to be on a control panel. if not controlled with electrical switches, how are they controlled?

when using block detectors, power must be run thru them, but their outputs are likely needed near the panel. power will come from a booster presumably located nearby the control panel.
 

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Discussion Starter #9
Greg,

from what I am reading, the turnouts, while they can e controlled by DCC, will likely start as push button on the control panel (with a LED or two, for display).
 

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what type of switch machines are you planning on using: twin-coil or stall motor (e.g. tortoise)?
 

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Discussion Starter #11
I am thinking twin coil, however I only recently heard about tortoise. not exactly sure if one is better than the other.
 

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tortoise machines have a couple of advantages. they are low current stall motors so you change the polarity and leave it on. that current is low enough that you can put a pair of LEDs in series to indicate position and they machines have contacts that can also be used for panel displays of frog polarity.

the current for a tortoise is low enough to be driven by a pair of lm324 op-amps

twin-coil require momentary power and are often used with capacitive discharge units. some may have extra contacts like tortoise.
 

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Sometimes you can get too much information. That is often the case with those considering DCC...Digital Command Control.

Actually, DCC while it's innards are complex digital electronics. it is the most simple model train system ever.
If you have the typical home layout, your installation is easy. Just plug the Controller into the power supply. Run
TWO wires to the track and you are ready to run 2. 3 or more trains at the same time, each individually
controlled. The controller puts an 'always on' appx. 14 volts square wave AC on the track. It also
sends out digital informantion to the track thru that same pair..

Each loco must have a DCC decoder that takes it's power and digital commands from the track thru the loco wheels.
Each loco has it's own digital 2 or 4 digit address. That's how the controller tells loco A to
go forward, while loco B is doing something else.

As you would expect, the larger the layout the more wiring you would need. It is recommended that
you have a drop from the track to an under table bus every 6 feet or so. The bus, of course,is
fed by your DCC controller.

The most popular DCC complete systems are: Digitrax, NCE, MRC and Bachmann. Any one
of them have sufficient power to run 4 or 5 trains at the same time. Bachmann lacks the
ability to do the 'fine tuning' of decoders that many like to do. All are of excellent quality so
your choice will be your preference as to the knobs and displays of the controller.
NMRA standards mean that you can run any brand loco or any brand decoder with
any brand of controller. In the event you decide to run several SOUND LOCOS
the power need goes up...but there are plug in boosters that provide what is needed when
you need it

Turnouts are what make a layout fun. But you must ignore any claims of
DCC 'compatiibility'...those are simply advertising hype. Any turnout is
sufficient for DCC. One of the most popular brands is Peco. You
simply do not have turnout caused derails using Peco. Most users choose their
insulfrog design. Howevver, if you use small 4 wheel or older locos lacking
all wheel power pickup you may need a turnout with powered metal frog.
Peco calls these Electrofrog.

There are two basic 'motors' to move the turnout points. One is the
old standby 'twin coil' that snaps at the push of a button. Many now
prefer the 'stall motor' design of Tortoise. It uses a DPDT switch to
throw the points. They move realisticaly slowly. The Tortoise also
has a built in swirtch to control RED/GREEN panel or track side signals.
Several makers offer 'stationary decoders' that let you throw your
turnouts using your DCC controller. Otherwise, you would need
a separate power source to provide current for either the twin coil
or Tortoise motors. On larger layouts the turnout control panels
may be located near the location of yards or other complex track work.
This reduces the volume of wiring.

Since you hope to move your layout to train shows from time to
time you must consider modulat benchwork. This also would
likely require that any turnout controls be on a panel for each module
else you would require cables with many conductoxrs.

Don
 

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Discussion Starter #15
Thanks for the replies. At this point, I am leaning towards not having the turnouts on DCC, and may make the move later. I'm still up in the air about tortoise controlled switches, as I don't think they have a distinct advantage.
 

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All of my turnouts were Peco twin coil powered thru a Capacitor Discharge Unit. The cap acts as a fast charging battery and
when you push the turnout panel button it discharges into theselected one of the twin coils moving the points. It protects the
coils from accidental burnout. Once such unit is able to power ALL of your layout turnouts.
But there is no way to control panel or track side signals. There is, however, a product
called The Staplelton 751D that does it all. You flip a switch on the panel, it moves the points AND controls the
panel LEDS. It also has a built in CDU to avoid burnouts.

The advantagfe of Tortoise turnout motors is that the one switch flip moves the points AND controls panel signals.
They are fully reliable but are intentionally SLOW...so you have to be aware to throw the turnouts before the
train gets there.

Don
 

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Discussion Starter #17
While having the turnouts moving slowly might look nice, I'm not sure if it's a good thing... Timing worries me. I may look into the CDU.
 

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You won't go wrong with twin coil turnouits. I do urge you to investigate the Stapleton 751 D. Had I know of the produict
when I built my layout I would havve used them. It's a complete unit and requires nothing extra to buy. You would need
a 12 to 16 volt DC source to power them and your turnout motors. You could use an old DC power pack or
an old unused wall wart that puts out the required DC voltage. With your knowledge of electronics and computers
you likely have an old power supply that would work. I used a household door bell transformer with the CDU to
power my turnouts.

Don
 

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The 751 requires a non switching power supply. I just got mine from Ken and they are super easy to assemble if you buy the kits.

Sent from my Moto Z (2) using Tapatalk
 

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One other advantage of a Tortoise is that it can reverse the polarity/phase of the turnout as needed. This can be handy at turning 'wye' configurations, for example.
 
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