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Best book about wiring a layout?

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Best book about wiring a layout?
Posted by crossthedog on Wednesday, March 17, 2021 12:36 PM

Happy St. Patties, all. My question is which book about wiring a layout you would consider the EASIEST TO UNDERSTAND, like an idiot's guide. Not the most complete, not the one with the sweetest schematics, and not the one that goes into the most detail about outlying scenarios that I probably won't be pursuing... but the one you would consider most easy to grasp for someone electronically challenged but that still covers essentials for basic wiring of a DC layout.

Plus points if it also covers DCC but I want to start with electricity as God first created it. 

Note: If you're an electrical wiz, empathy will be required to answer this question properly.

Thanks in advance for any opinions offered. I'll check back daily.

-Matt

Tags: basic wiring , books , DC

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Posted by rrebell on Wednesday, March 17, 2021 1:43 PM

Atlas book on wiring.

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Posted by SeeYou190 on Wednesday, March 17, 2021 4:40 PM

I am going to agree with RRBELL. The Atlas wiring book has all the basic information you need and should be your first choice for the basic nuts-and-bolts.

The old Kalmbach book HO Primer had some very good basic information on DC wiring.

Avoid the Kalmbach book How To Wire Your Model Railroad unless you are 100% sure you are getting the newest edition. Old editions of that book contain way more than basics and are overly complex and outdated.

-Kevin

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Posted by Lastspikemike on Wednesday, March 17, 2021 6:13 PM

The really useful thing about the Atlas wiring book is they show all the schematics for the internals of their switches. So even non electrically minded people can work out the current flow through the switches. Understanding that helps understand the rest of the wiring needed for DC operation.

The other aspect is you can just wire according to their diagrams and descriptions and it will work even if electrical stuff isn't your thing.

Atlas includes information to allow you to understand how it's supposed to work but also sets out how you do stuff without needing to understand how it works. 

Very handy and very well written and illustrated. 

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Posted by riogrande5761 on Thursday, March 18, 2021 6:47 AM

The Atlas book appears to rely on their products naturally, which may be ok depending on your needs.

Those other two books may offer useful info, but they look like they are from the 1950's or 1960's.  Some more recent books, say written in the last 20 years may be able to discuss and take advantage of some modern things including modern connectors and hardware that wasn't common way back when dinosaurs roamed the earth.

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Posted by gregc on Thursday, March 18, 2021 8:09 AM

i think the problem with books like these is they often explain just one approach.    today there is of course DC, cab control, DCC and possibly dead rail wiring.

another aspect of wiring is finding shorts.    even wiring for DCC can benefit from blocks or power districts, both to limit shorts due to derailed equipment or shorts due to mis-wiring or gap closures due to expansion.

i think i was fortunate to get an HO Railroad that Grows in my teens.   Linn Westcott just needed a chapter or two (pre-Atlas) to describe how to build a cab control system

there are of course many web pages on model railroad wiring

i think the NMRA can do better than Wiring.   the advantage of a web page is improvements can easily be added over time.

 

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Posted by Lastspikemike on Thursday, March 18, 2021 8:49 AM

DCC wiring is very, very simple until you get into large layouts with multiple operators. Most home layouts, even quite big ones, can be wired with just a two wire bus and lots of feeder connections to the rails. 

Adding separated power districts, even if only for future use, is as simple as fitting two isolating joiners at conveniently logical places in the layout, relying on those feeders to power now isolated sections of track. That's it. Only when you wish to "upgrade" your DCC layout to add power boosters or power district circuit breaker protection does it get a little more complex but there are pre-built components that simplify even that process.

DC multiple cab and multiple block control is where the Atlas book helps. You don't need to use the actual Atlas products because they also very kindly include switch schematics.  I suspect at the time they wrote this book Atlas actually made cost effective good quality switchgear. I suspect they have not changed that stuff in decades. Manufacturing quality seems to have declined.

If you're  not intending to run a complex DC layout just wire your layout for simple DCC operation,  with a two wire bus and multiple track feeders. The only tricky parts for DCC are reversing loops and any sections of track you want an "off" switch for. Same tricky problems as for DC and with very similar solutions. In fact reversing sections are far easier to wire and automate using DCC  

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Posted by rrebell on Thursday, March 18, 2021 10:05 AM

Atlas my list their products but other products can be substituted. 

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Posted by crossthedog on Thursday, March 18, 2021 10:46 AM

Survey says?....
The Atlas wiring book. Thanks fellas. I'm on it. I particularly like the idea of seeing the path of the electricity through the switches; I learn visually.

Still open to differing viewpoints, but I think I know my first move now.

 

Now anybody know how to edit or create a signature? I thought I had supplied one but this Trains.com world is so confusing.

 

UPDATE 3/18: I wrote the above yesterday, thought I'd posted it but hadn't. Clicked send this morning and then saw several new responses, which I appreciate and will consider.

-Matt

 

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Posted by snjroy on Thursday, March 18, 2021 11:39 AM

I think it really depends whether you are in DC or DCC. Not offense to the others, but the DC books contain a lot of information that is not really relevant to DCC. In fact, there are things in there that should not be done for a DCC layout... I bought the Kalmbach book "Basic DCC wiring for your Model Railroad", and I think it does the job in terms of covering the basics. If you want to learn basics about electricity, then I would suggest you read a more generic source of information that covers the basics, like what voltage, amps, resistance, watts, alternative current, and direct current mean. There are really good sites out there that explain it.

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Posted by dknelson on Thursday, March 18, 2021 11:47 AM

The Atlas book (books?) is/are easy to understand and is/are very clearly illustrated BUT I do believe it is all tied to the "common rail" version of DC wiring which in turn is also the system that the Atlas components are tied to.  That is a perfectly good system but it is my understanding that some have found it easier to convert the non- common rail wiring layout to DCC when the time comes.  Fewer new gaps needed for power districts and that sort of thing.  In any event the Atlas books pretty much ignore DC wiring which is not common rail.  And if you use Atlas components, that's fine.  You don't have to understand so much, you just connect stuff the way the drawings tell you.  

The Linn Westcott book still has things of value for those wanting DC wiring but it dates from an era when guys were building their own power packs, so it goes into a lot of electrical and DC theory, and LHW was also an early adopter and promotor of technology such as progressive cab control which never really took off.  The consequence is that large swaths of the book are outdated or irrelevant.  Who today for example needs to know how to hook up an electric motor to the rheostat or potentiometer on their throttle so they could get momentum?

I happen to think that Andy Sperandeo's Kalmbach book on wiring is more clear and easier to follow than Westcott's, and being more recent is able to eliminate the most outdated stuff.  Ironically the least useful parts are those that deal with DCC because it was issued very early in the DCC era.  For those wiring to DC standards, and who want to know the pros and cons of Atlas's common rail system, I'd look for Sperandeo.  For the most part Sperandeo is careful to provide content for those using Atlas components and common rail rather than DPDT or rotary switches and non-common rail for example.  

I was not that impressed with Larry Puckett's book on wiring, which superceded Sperandeo's.  You could sense his impatience with the whole idea of DC wiring, for perhaps understandable reasons.  He knows his stuff of course so it is far from worthless and I imagine many layouts were wired nicely using only Puckett's book.   But also I never found Puckett to be a very clear writer in his monthly column in MR, nor in this book (nor do I find Mark Juett to be a very clear writer about wiring in the NMRA magazine).  And perhaps as a consequence, I think both Westcott and Sperandeo as book authors were better able to communicate with the Kalmbach illustrators who had to provide drawings to match the text.  That is an important factor in a good wiring book: can the illustrators understand the text well enough to provide a truly helpful drawing?

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Posted by SeeYou190 on Thursday, March 18, 2021 12:40 PM

dknelson
BUT I do believe it is all tied to the "common rail" version of DC wiring which in turn is also the system that the Atlas components are tied to. 

Great point.

If your plan is to build a DC layout and then convert it to DCC, which reading the original post might be the plan, common rail should be avoided.

Listen to the DCC guys (not me) if this is the plan.

-Kevin

Wink Happily modeling my STRATTON & GILLETTE RAILROAD. A Class A line located in a personal fantasy world of semi-plausible nonsense on Tuesday, August 3rd, 1954.

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Posted by ATLANTIC CENTRAL on Thursday, March 18, 2021 1:00 PM

Paul Mallery's Electrical Handbook vol 1 & 2, enough theory so you can advance, without boring you silly. Covers the basics, and starts you on the advanced path if you are interested.

Mallery had his own ideas, some never tried, about possible advanced versions of DC. Some of which I did use and perfect in my Advanced Cab Control system. 

Ed Ravenscroft was also a forward thinker, just reading his MZL Control series in MR is full of DC ideas that can be applied separately without using his whole system.

His system, some of Mallery's ideas, and my experiences at the Severna Park Model Railroad Club set the basis for my Advanced Cab Control - DC without block toggles......... but without the limitations of Wescott's progressive cab control.

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Posted by Lastspikemike on Thursday, March 18, 2021 1:43 PM

If you're building a new layout then common rail isn't needed any longer. It's still handy for multiple block multiple cab DC only layouts.  There's no magic or complication involved in common rail, it's the simpler way to wire for DC. Common rail is also fully compatible with a single booster DCC system.

For a simple single booster DCC common rail is fine because you'll be wiring a two wire bus. A common rail IS a single wire bus. Basic DCC is just two individual  "common rails", one "left" and one "right"  

If you have a DC layout already wired for one common rail it is very simple to convert to DCC. You connect one power wire to the common rail track power points and the other power wire to the main feed to all the blocks. Then select one side of all the blocks to be powered at the same time. 

If you want to convert common rail DC with block control to DCC you simply locate every isolated rail joint on your layout and then add a second isolation joiner at the same spot in the other rail.  If you also have lots of feeders then that's it. If you happen to have not put two power feeders to both rails in any one block then you'll need to add that second power feeder you ought to have installed in the first place. Then that's it for converting to DCC.

Our DC three cab 24 block layout consists of double isolated blocks with the one side powered as a common rail by wiring all that side connections together underneath the tabletop. If you fit two-side rail feeders where you ought to have then even a common rail DC layout is easily converted for a two wire bus DCC system.

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Posted by ATLANTIC CENTRAL on Thursday, March 18, 2021 2:27 PM

Even with DC there are lots of good reasons not to use common rail or common return wiring.

I have 10 DC wireless throttles, each with its own 4 amp power supply. When they are connected to a section of track, they are completely isolated from the other power supplies.

This provides a long list of benefits including being the basis of my free Automatc Train Control. If you run a red signal, you train just stops, it does not get picked by some other throttle in the next block, it does not create a short, it just stops.

But then again I don't have any block toggles or rotary switches either, that is done another way.......

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Posted by RR_Mel on Thursday, March 18, 2021 3:11 PM

All good suggestions above!  If you run into problems just post them here, tons of free information is available on this Forum.

 

Mel



 
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Posted by crossthedog on Thursday, March 18, 2021 8:38 PM

Thanks for the feedback, everyone. Somewhere in my online forum reading (all a confusion in my head now) I think I made a 'note to self' not to use common rail, whatever it was. I think I remember learning that if I just ran bus wires under the basic track plan with feeders at key points I could then use a DPDT to switch between DC and DCC, running the layout one way or the other.

I foresee my normal DC operations being running a longer passenger or freight on my loop while doing some switching on isolated spurs, so maybe two locos at a time, max, because it'll just be me. I don't have modeler friends (present virtual comp'ny excepted) and don't foresee operating sessions happening in my dank garage. So I don't think I need many blocks or many throttles/cabs.

Even when I run DCC, which I want to do sooner than later, it will still only be one or two engines -- one on the continuous loop and one in the yard or spotting cars outside of town. 

Also, I'm avoiding reverse loops. I have enough room for a tight dogbone.

So I think I might get several of the books mentioned. It doesn't surprise me that the writers of yore were better at communicating. But I also hear your cautions that much of their stuff is obsolete, and I would have expected that. 

Finally, from the comments here I can see I need to settle my track plan. I thought I had it down but then started lying awake at night, playing with the idea of two separate, not-connected plans within one layout, DC on an outside ovalish loop with a small yard outside the loop, and DCC starting on the inside and rising out of (and crossing over) the DC loop into more creative switching scenarios. That way I would have zero chance of frying any engines, and I could wire each set of tracks in the way that was best for each.  Not sure, though. I don't like any of the designs I came up with for getting up and out of the interior without it looking like a ramp.

Still cogitating...

-mdf

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Posted by SeeYou190 on Thursday, March 18, 2021 11:06 PM

crossthedog
Finally, from the comments here I can see I need to settle my track plan. I thought I had it down but then started lying awake at night

I have been fleshing out the details of my next layout in my head for about seven years when I decided that the spare bedroom layout was not my final layout.

I still have not fully settled on a plan.

-Kevin

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Posted by rrinker on Thursday, March 18, 2021 11:22 PM

 If you build a dogbone layout, and have any crossovers int he narrow part where the two tracks are close together, you have reverse loops. The easiest way to wire a dogbone is to make the two end loops reversing sections, then you can have any number of crossovers without creating a reverse loop situation.

                           --Randy


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Posted by Lastspikemike on Friday, March 19, 2021 8:52 AM

The difference in wiring for common rail or for two wire bus is whether you fit isolators to both rails or just one rail. It is advantageous to fit isolators to both rails as you build the layout whether you build for DC or DCC and whether you decide to run common rail or not. Common rail only becomes an issue if you add a second powerpack to your layout. That would be the "common" part. It is the connecting of one side of two or more powerpacks  to each other that creates the common rail. Using just the  one DC powerpack or one DCC power booster means each of the rails is always a  "common" rail regardless of how you wire the layout.

No need to avoid reversing loops, they are not as troublesome as they at first might appear. If you fit one just crossover into your dogbone you create a reversing section, two actually. Better to fit those isolators into the two connecting diverging routes as you build. Worry about wiring in the necessary polarity reversing switch later. Remember to deliberately select the length and position of any reversing section to accommodate your longest expected train and then just wire it properly. It's not difficult to do. 

Wiring for double isolated track blocks each with its own sets of feeder wires from the two bus wires to the track rails is the most useful and flexible way to lay out your track whether you fit DC or DCC and intend to use just one power pack or booster or more than one.

Creating a series of well organized and logical electrically isolated sections of track is well worth doing no matter how big your initial layout is. It may well be made bigger or more dense or likely both at some point. Electrically, well organized track is really valuable for many reasons and need not be complicated to wire initially. Even a simple two wire bus DCC single booster layout benefits from having seperate double isolated blocks of track.

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Posted by snjroy on Friday, March 19, 2021 11:45 AM

I'm not an expert, but reversing the polarity on a DCC layout for a return loop operation sounds risky to me, especially if there are other trains operating elsewhere on the layout. And I would not want to see a DCC locomotive accidently go through a section with an inverted polarity. Something tells me that the Poof effect will appear!

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Posted by SeeYou190 on Friday, March 19, 2021 11:47 AM

rrinker
The easiest way to wire a dogbone is to make the two end loops reversing sections, then you can have any number of crossovers without creating a reverse loop situation.

Randy, I have thought this myself. Am I understanding this right...

On a dogbone layout with a narrow center section with crossovers, wire the narrow section directly to the DCC system, and put auto-reversers on both end loops.

Is that correct?

-Kevin

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Posted by Texas Zephyr on Friday, March 19, 2021 1:12 PM

snjroy
I'm not an expert, but reversing the polarity on a DCC layout for a return loop operation sounds risky to me, especially if there are other trains operating elsewhere on the layout. And I would not want to see a DCC locomotive accidently go through a section with an inverted polarity.

Usually the auto-reverse is applied to the reversing loop.   But a DCC locomotive going through a section with inverted polarity is exactly how the auto reversers work.  They sense the short and flip the polarity.   Because DCC is bi-polar one can flip the polarity under a DCC locomotive and it doesn't effect it.

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Posted by Lastspikemike on Friday, March 19, 2021 2:57 PM

snjroy

I'm not an expert, but reversing the polarity on a DCC layout for a return loop operation sounds risky to me, especially if there are other trains operating elsewhere on the layout. And I would not want to see a DCC locomotive accidently go through a section with an inverted polarity. Something tells me that the Poof effect will appear!

Simon

 

There is no polarity in DCC, you have wave phase that seems to be similar but really isn't. Polarity is resolved in the decoder through a diode rectifier bridge. So the decoder really doesn't care which way round the wave phase is at any given moment (phase alternates about 9000 times a second). 

What matters to a decoder is the phase be the same for each side of the power pickup by the locomotive (or a metal conducting wheel on a piece of rolling stock  crossing an insulated rail gap, for example). The phase must alternate from rail to rail across the gauge. It must never alternate (or try to) within a rail on one side of the gauge.

Auto reversers beat the power booster circuit protector by reacting much more quickly to this phase "short" as the wheel crosses the insulated gap by tripping at a lower current. Auto reversers also then use that "short" signal not to cut out power but to reverse wave phase inside the reversing section and prevent power from cutting out. Using a very brief short to prevent an actual power outage short.  The potential wave phase conflict caused by the metal wheels never gets enough time to "throw the breaker" in the power booster.  The decoder receives the wave phase flip but that is no different to any of the other 9000 flips occurring everywhere on the layout. Those flips just need to always be "in phase" for each locomotive. It doesn't matter if one locomotive is out of phase with any other locomotive. You can have two locomotives in phase but travelling in opposite directions (consist). This only works in DC if polarity is the same. For DCC two locomotives can be out of phase but travelling in either opposite directions or the same direction which is why you really need convenient consisting coding for a DCC system. Just turning one A unit around doesn't work, the decoder polarity conversion downstream of that integral rectifier also has to be flipped. That can only be done inside the decoder. It may help to realize that the reversing switch (which you will note is in the throttle, not the power booster in DCC) does nothing to track "polarity" or phase. That throttle reversing switch alters the signal component of the wave to tell the addressed decoder and only that decoder to flip the DC polarity inside the decoder.  That's why flipping the track phase ("Polarity")  under the locomotive can have no effect on locomotive direction inside a reversing loop (or anywhere). Power phase changes in the track are not part of the decoder signal.   At least they're not supposed to be but under some conditions some decoders do get fooled. DCC is a bit weird if you start digging into it very much. For example, a QSI decoder can be tricked into blowing a DCC locomotive horn when running on DC because the decoder has a nifty (or annoying depending on your opinion of QSI) bit of software that can "see" a very quick track polarity flip  as a sort of pseudo DCC signal. As I say, DCC is a bit weird if you analyze or examine it in too much depth or detail.  

For DC the convention for fluid motion through a reversing section results in fitting the polarity reversing device so as to reverse the polarity of the track outside the reversing section (generally referred to as the "main").  Polarity matches going in to the reversing section but polarity would not match going out unless it gets flipped. So, when the train is fully inside the reversing section (tail end metal wheels included) the polarity outside the reversing section is flipped to match polarity at the exit to the reversing section. The train inside the reversing section never experiences reversed polarity. But, it matters to every other locomotive outside the reversing section on the main polarity, unlike DCC. Outside the reversing section all other locomotives will reverse direction when the polarity is reversed on the main to match  the DC reversing loop exit.  Big difference in how you may operate. 

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Posted by ATLANTIC CENTRAL on Friday, March 19, 2021 6:42 PM

SeeYou190

 

 
rrinker
The easiest way to wire a dogbone is to make the two end loops reversing sections, then you can have any number of crossovers without creating a reverse loop situation.

 

Randy, I have thought this myself. Am I understanding this right...

On a dogbone layout with a narrow center section with crossovers, wire the narrow section directly to the DCC system, and put auto-reversers on both end loops.

Is that correct?

-Kevin

 

Yes, and there are good reasons to wire a DC layout of that configuration in a similar way.

Again assuming the center of the dogbone is intended to simulate a double track mainline with crossovers.

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Posted by ATLANTIC CENTRAL on Friday, March 19, 2021 6:53 PM

Lastspikemike

For DC the convention for fluid motion through a reversing section results in fitting the polarity reversing device so as to reverse the polarity of the track outside the reversing section (generally referred to as the "main").  Polarity matches going in to the reversing section but polarity would not match going out unless it gets flipped. So, when the train is fully inside the reversing section (tail end metal wheels included) the polarity outside the reversing section is flipped to match polarity at the exit to the reversing section. The train inside the reversing section never experiences reversed polarity. But, it matters to every other locomotive outside the reversing section on the main polarity, unlike DCC. Outside the reversing section all other locomotives will reverse direction when the polarity is reversed on the main to match  the DC reversing loop exit.  Big difference in how you may operate. 

Actually if you design and wire your cab control system correctly, each separate throttle will have its own main and reverse loop switches, and they will only affect the blocks connected to that throttle, and have no effect on other throttles running other trains in other blocks.

A much better approach........just one of many much better approaches to DC

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Posted by gregc on Friday, March 19, 2021 7:37 PM

snjroy
I'm not an expert, but reversing the polarity on a DCC layout for a return loop operation sounds risky to me, especially if there are other trains operating elsewhere on the layout.

the track voltage on each rail in DCC is constantly alternating.   a rectifier in the decoder makes this DC just as the rectifier in an DC throttle rectifies the AC power from the wall.

motor direction is not determined by track polarity.    the DCC command station sends a DCC command over the track telling the decoder which direction the loco should move.  the decoder controls the motor voltage using an h-bridge.   

just as in DC, each rail of a DCC reversing section must be gapped to prevent a short and the connections between the reversing and mainline rails may need to be swapped even though they are alternating because they are alternating in opposite directions.

but unlike DC, a DCC auto reverser can very quickly (within a msec) detect a short and reverse the polarity of just the reversing loop when a loco bridges the gaps of a reversing section that have opposite polarity.

capacitance in the decoder prevents it from reseting due to the brief loss of power due to the short.   the decoder will detect and discards any DCC command corrupted due to both the loss of power and the reversing of polarity.    reversing the track polarity only affects locos in the reversing section.

digtalal bits are communicated over the track based on the time between polarity reversals -- hence why DCC track voltage is constantly alternating and why reversing track polarity corrupts any DCC command when the polarity is reversed.

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Posted by SeeYou190 on Friday, March 19, 2021 8:41 PM

ATLANTIC CENTRAL
Actually if you design and wire your cab control system correctly, each separate throttle will have its own main and reverse loop switches, and they will only affect the blocks connected to that throttle, and have no effect on other throttles running other trains in other blocks.

This is my approach to the reverse loop in DC.

On my layout there will only be one reversing section, except for the two turntables.

This section of track that will need to be reversed will only be controlled by one throttle, and trains will alternate Northbound and Southbound through this section.

To make the reversing section seemless, there will be two industries in this section, one with a trailing point turnout Northbound, and one with a trailing point Southbound. All trains going through this section will need to switch a car at one of these industries.

So, as you go Southbound, the train stops, and reverse direction to either pick up or set out a car at one of the industries. As you go Northbound, same thing.

The FIRST directional change for switching will be done with the polarity reverser for that electrical block. All other direction changes will be done with the power pack. Then when you leave the block, polarity will be correct, and correct for the next train entering the block.

Very simple, no electrical tricks to remember.

I believe I read about this operating scheme in an article from a 1950s Model Railroader.

-Kevin

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Posted by Lastspikemike on Friday, March 19, 2021 9:31 PM

ATLANTIC CENTRAL

 

 
Lastspikemike

For DC the convention for fluid motion through a reversing section results in fitting the polarity reversing device so as to reverse the polarity of the track outside the reversing section (generally referred to as the "main").  Polarity matches going in to the reversing section but polarity would not match going out unless it gets flipped. So, when the train is fully inside the reversing section (tail end metal wheels included) the polarity outside the reversing section is flipped to match polarity at the exit to the reversing section. The train inside the reversing section never experiences reversed polarity. But, it matters to every other locomotive outside the reversing section on the main polarity, unlike DCC. Outside the reversing section all other locomotives will reverse direction when the polarity is reversed on the main to match  the DC reversing loop exit.  Big difference in how you may operate. 

 

 

Actually if you design and wire your cab control system correctly, each separate throttle will have its own main and reverse loop switches, and they will only affect the blocks connected to that throttle, and have no effect on other throttles running other trains in other blocks.

A much better approach........just one of many much better approaches to DC

Sheldon

 

I was referring to single powerpack layouts. 

My reversing sections use Atlas Controller switches so have dual cab control for any block or reversing section. Adding the third cab to this setup stumped me. So far.

Alyth Yard

Canada

  • Member since
    January 2009
  • From: Maryland
  • 10,529 posts
Posted by ATLANTIC CENTRAL on Friday, March 19, 2021 10:19 PM

Lastspikemike

 

 
ATLANTIC CENTRAL

 

 
Lastspikemike

For DC the convention for fluid motion through a reversing section results in fitting the polarity reversing device so as to reverse the polarity of the track outside the reversing section (generally referred to as the "main").  Polarity matches going in to the reversing section but polarity would not match going out unless it gets flipped. So, when the train is fully inside the reversing section (tail end metal wheels included) the polarity outside the reversing section is flipped to match polarity at the exit to the reversing section. The train inside the reversing section never experiences reversed polarity. But, it matters to every other locomotive outside the reversing section on the main polarity, unlike DCC. Outside the reversing section all other locomotives will reverse direction when the polarity is reversed on the main to match  the DC reversing loop exit.  Big difference in how you may operate. 

 

 

Actually if you design and wire your cab control system correctly, each separate throttle will have its own main and reverse loop switches, and they will only affect the blocks connected to that throttle, and have no effect on other throttles running other trains in other blocks.

A much better approach........just one of many much better approaches to DC

Sheldon

 

 

 

I was referring to single powerpack layouts. 

My reversing sections use Atlas Controller switches so have dual cab control for any block or reversing section. Adding the third cab to this setup stumped me. So far.

 

Well, you can't do it with that stuff from Atlas, but when you want to know, look me up.

A properly set up can control system can have as many throttles as you want and be much more "user friendly".

My mainline will have six throttles available, other areas of the layout will be able to connect to them, as well as having additional separate throttles.

My throttles are wireless radio, but good DC control schemes will work with any kind of throttle.

Here is the thing about DC - except some of basic rules, follow some proven conventions, decide what features you want, and a number of different possible user friendly systems can be put together.

Some require more wiring and hardware, some are pretty simple, but most of the good ones don't use block toggle switches in the traditional sense.

If you have access to the MR archives, look up a series of articles by Ed Ravenscroft starting in Feb 1974 about his MZL control. It is just one of many great DC systems over the years.

If you do look it up, don't get too caught up in the exact wiring, he used a very old detection circuit and built his own throttles. But his operational premise is genius.

While a lot of what you have posted on here is true and works, most of it has limitations that are a dead end for expansion or easy use beyond what you have done.

And while a common rail or common buss system was popular decades ago, the use of modern throttles will go better with complete isolation of each throttle.

My ten throttles each have their own power supply and from power supply to locomotive the power supplies are never connected to each other as the 10 trains move about the layout.

When I was a young man I was, among other things, an electrical control systems designer, back in the days of relays, before computers. Systems that controlled pumping stations, auto assembly lines, steel mills, process machinery of every sort.

When Programable Logic Controllers came along, I learned them and I learned how to re-write relay logic into PLC programing.

Today I would rather use a relay than a computer to control a model train.....

Sheldon

 

    

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