Common return using two different types of controllers?

[kevinlms]

1 hour ago, AndyID said:

 

Hi Clive,

 

It says never to connect the secondaries of two transformers in parallel which is absolutely correct. That is a major no-no. Unfortunately the diagram is wrong as it appears to show two controllers with their outputs connected to each other.

 

Obviously two controllers with connected outputs isn't going to be useful but it's not a safety issue. It's also has nothing to do with common return. (If it was a safety issue with common return it would be just as much of a safety issue with non-common return wiring.

 

Cheers!
Andy

That diagram as part of the instructions is not wrong, because they belong to a 'transformer package' and not a controller package.

 

I guess the diagram looks wrong, because it does look like a controller, but the diagram belongs with a Gaugemaster Transformer Fitting Kit - GMTFK1 - 2. It is not a controller.

[Clive Mortimore]

19 minutes ago, Sol said:

Clive, using two wires per section & not common return, have you thought what is the result when a loco straddles two sections controlled by two different controllers? The outputs are joined - commoned on two wires.

 

I never run a train from one section under the control of one controller to a section under the control of another controller. 

 

Set the route, then set the section switches, before moving the train. 

 

Operational discipline. 

[Sol]

Clive, no doubt it works well for you. Not sure when you get multiple operators on a layout like this one

https://banburyconnections.weebly.com/operations.html

Excerpt...

Operating the railway is relatively complex as trains run between control panels and operators transfer trains to each other in transfer sections, often whilst the train remains in motion. This allows for the through running of trains across multiple control panels staffed by different operators. Each electrical section on the railway is either controlled by a switch on one of the control panels or is point isolated. Trains are driven using conventional DC controllers of generally British manufacture. Operators need to be familiar with their station’s track layout which corresponds with the diagram on their control panel. A Manual has been prepared by one enthusiast to assist in panel familiarisation!  

The complexity of the railway is enhanced by about 250 working hand operated semaphore signals.

[Clive Mortimore]

16 minutes ago, Sol said:

Clive, no doubt it works well for you. Not sure when you get multiple operators on a layout like this one

https://banburyconnections.weebly.com/operations.html

Excerpt...

Operating the railway is relatively complex as trains run between control panels and operators transfer trains to each other in transfer sections, often whilst the train remains in motion. This allows for the through running of trains across multiple control panels staffed by different operators. Each electrical section on the railway is either controlled by a switch on one of the control panels or is point isolated. Trains are driven using conventional DC controllers of generally British manufacture. Operators need to be familiar with their station’s track layout which corresponds with the diagram on their control panel. A Manual has been prepared by one enthusiast to assist in panel familiarisation!  

The complexity of the railway is enhanced by about 250 working hand operated semaphore signals.

Your layout?

[Sol]

No Clive. my layout is DCC and a lot smaller - just 5 operators

http://www.nmra.org.au/Layout_Tours/Ron Solly/index.html

http://www.nmra.org.au/Operations/Systems Of Operation.html        Devan and Summersett

[AndyID]

31 minutes ago, Sol said:

Clive, no doubt it works well for you. Not sure when you get multiple operators on a layout like this one

https://banburyconnections.weebly.com/operations.html

Excerpt...

Operating the railway is relatively complex as trains run between control panels and operators transfer trains to each other in transfer sections, often whilst the train remains in motion. This allows for the through running of trains across multiple control panels staffed by different operators. Each electrical section on the railway is either controlled by a switch on one of the control panels or is point isolated. Trains are driven using conventional DC controllers of generally British manufacture. Operators need to be familiar with their station’s track layout which corresponds with the diagram on their control panel. A Manual has been prepared by one enthusiast to assist in panel familiarisation!  

The complexity of the railway is enhanced by about 250 working hand operated semaphore signals.

 

But it doesn't really make any difference whether it's common return or not. Clive implemented his route selection system using a two wire method and I'm sure it works very well. The same system could also be implemented using a common return (CR) method. The same is true for Banbury. In operation there is no difference. You can use cab-control or route selection or anything else with two wire or common return. Common return and cab-control are two very different things.

 

Personally I prefer to use CR because there are fewer connections to make, fewer isolation breaks, fewer switch contacts (a reliability benefit) and fewer wires under the baseboard but if anyone chooses not to use common return it does not bother me at all. But I do get bothered when people try to dissuade others from using CR for all sorts of wavy-arm, spurious reasons.

[AndyID]

2 hours ago, kevinlms said:

That diagram as part of the instructions is not wrong, because they belong to a 'transformer package' and not a controller package.

 

I guess the diagram looks wrong, because it does look like a controller, but the diagram belongs with a Gaugemaster Transformer Fitting Kit - GMTFK1 - 2. It is not a controller.

 

The diagram is clearly wrong. It should not take the combined intellects of an electrical engineer and a lawyer to interpret it.

[kevinlms]

2 minutes ago, AndyID said:

 

The diagram is clearly wrong. It should not take the combined intellects of an electrical engineer and a lawyer to interpret it.

The problem is that it looks like a controller, if the circle and blob looking like a reversing switch, were deleted, then it would be accurate. 

[AndyID]

13 minutes ago, kevinlms said:

The problem is that it looks like a controller, if the circle and blob looking like a reversing switch, were deleted, then it would be accurate. 

 

I completely agree Kevin. The problem is that we (and I'm as guilty as anyone) tend to look at the pics before we carefully analyze the text ("a picture speaks a thousand words" is really true). I hope Gaugemaster fixes it by substituting an appropriate symbol for a transformer.

 

Edited July 25, 2019 by AndyID
more info

[Demondrille Junction]

I'm glad that diagram has come up.  It confused me before and more recently during my search into controllers. Like Governor said earlier, it's a diagram they've used on a few instruction sheets but changed wording to suit.  I didn't really understand what they meant until some answers provided in this thread, so thank you all. 

 

With regards to common return, the need for one transformer per controller, and the GM panel controllers and transformers; I don't know too much about transformer construction but can I assume the T1 pictured below with two outputs has two independent secondary windings and can be considered as two separate transformers? I believe that's what 34theletterbetweenB&D was referring too on the first page but have to check. "... two separate transformers,* one per track output, (or two completely independent low voltage windings on a common transformer frame) are required for this device, ... "

 

I'm not getting a a T1 but to free up a mains socket I had thought previously about replacing the two wall warts for my twin panel controller with a cased M1 transformer which I only assume is similar inside to the T1.  

 

 
 

 

[Crosland]

17 hours ago, Clive Mortimore said:

And what does this say?

 

http://www.gaugemaster.com/instructions/GMTFK12.pdf

 

It says "It is very important that the outputs of two or more transformers are not connected together in parallel.". That's just common sense, but has nothing to do with common return.

 

Common return wiring does not parallel the outputs. It creates a single point of reference between two separate circuits.

[Crosland]

16 hours ago, Nearholmer said:

Are you confident that there can never be a risk of back-livening by parallel connecting the outputs of controllers if they are switch-mode power supplies, as opposed to more traditional arrangements? I have to confess that I get confused on this point.

 

 

Yes, full stop.

[Crosland]

9 hours ago, Demondrille Junction said:

can I assume the T1 pictured below with two outputs has two independent secondary windings and can be considered as two separate transformers?

 

Yes, for the purposes of this discussion.

[Clive Mortimore]

I won't try and help in future with my own experience, I am so glad all of those who  have said I am wrong have shown Demondrille  how they would wire up his layout  with common return and four controllers. 

 

All I hope that with using common return that Demondrille doesn't have a fault that he can't trace because of the common return. Not using it makes fault finding easy.  I think I mentoned that in my first post on this thread.......but I must be wrong. 

[Nearholmer]

How about a compromise?

 

- when working in 2-rail, I do exactly as you, Clive, and section and switch both poles, because it avoids silly mistakes; and,

 

- when working in 3-rail, I use common return, sectioning and switching only the “third rail”, because it is utterly unnecessary to do otherwise, and it seems much more like the real thing.

 

Not entirely logical, but it works for me.

 

Kevin

[Sol]

6 hours ago, Clive Mortimore said:

I won't try and help in future with my own experience, I am so glad all of those who  have said I am wrong have shown Demondrille  how they would wire up his layout  with common return and four controllers. 

 

All I hope that with using common return that Demondrille doesn't have a fault that he can't trace because of the common return. Not using it makes fault finding easy.  I think I mentoned that in my first post on this thread.......but I must be wrong. 

 

Clive, you are not wrong in not using common return but it does work even in real life.      And I did point to this site http://www.rail.felgall.com/cc.htm

which does give versions of wiring and if all Demondrille's wiring is drawn out & labelled, fault finding is not that hard.

 

Another web page that explains  common return http://www.rail.felgall.com/crw.htm

 

[kevinlms]

8 hours ago, Clive Mortimore said:

I won't try and help in future with my own experience, I am so glad all of those who  have said I am wrong have shown Demondrille  how they would wire up his layout  with common return and four controllers. 

 

All I hope that with using common return that Demondrille doesn't have a fault that he can't trace because of the common return. Not using it makes fault finding easy.  I think I mentoned that in my first post on this thread.......but I must be wrong. 

Its been pointed out earlier in the thread that what you are doing is not wrong.

 

Please stop suggesting that anyone is saying so.

[Demondrille Junction]

8 hours ago, Crosland said:

 

Yes, for the purposes of this discussion.

Thanks Crosland. After I posted I thought I should just ask GM but got an "unable to process" error when trying to submit the online email form. It seemed obvious but I wanted to check.

 

Sol, thanks for that second link. I have seen Steve's Railway Pages before but forgot about that page on CR, I've got a terrible habit of not adding pages to favourites. And Clive, thanks for your contributions and vids too, it's all been taken on board. 

 

When researching CR I came across an old thread in modelrailforum where someone had a Morley go south when it interacted with a Gaugemaster. Unfortunately it doesn't go into detail on how it happened or what exactly happened, but that's what spurred my initial research and question after not being able to find answers.  Since then I can conclude compatibility isn't an issue between different types of controllers to implement CR.  However, some points that are prominent in one of 34thletter's post  'If you have the knowledge of the underlying principles, necessary technique and the skill to apply it'  I can confidently say at the moment I'm not there yet. And what DavidCBroad said 'Sooner or later you will connect both controllers to the same bit of track', well that's happened too a number of times just with the two sides of the GM as I've wired crossings incorrectly. Eg, an Up Main loco has traveresed a crossing and affected a stationary or moving Down Main loco. So I'm still learning and making silly mistakes with a long way to go.

 

 

 

[St Enodoc]

On 23/07/2019 at 01:32, Demondrille Junction said:

 Oh I hope not. This subforum seems to be the most DC friendly place there is with a knowledge base to suit. It's refreshing not to have to justify why one wants to meddle with at times complicated DC problem solving when asking questions.  

 

Thanks to all that have responded.  I believe my biggest problem will be me implementing common return correctly so far as poor planning and making silly mistakes is one of my attributes .  So I'm leaning towards running pairs of wires where needed and implement cab and block control with appropriate switching to create some interlocking.  I started with an interesting perhaps  complicated prototypical track plan without any circuitry or electrics included in my interpretation.  I threw down flex track and modified electrofrog points to match the plan then soldered every join with the aim of cutting in isolating, expansion and block sections later, some of which I've done.  Needless to say there's been a lot of short circuits up to this point.  To move forward I'm going to have to do what I'm not good at, a proper plan and implement some order and neatness.  I've not used uniform colour codes for wires either and I've recorded nothing so far on what I've done, just keeping it in my head and it's getting crowded in there.  I still think common return will have a place in regards to the Seeps and later signalling plus relays I plan on installing but every system will have it's own common return except the controllers which will all be separated. 

 

There's a simplified, condensed plan of the layout below, basically highlighting the points and crossings involved. Minimum of three controllers for starters with one for Up Main, Down main and Branch.  Where one controller hands off to another, say when a train traverses down main to down branch, I'll just have to bring the train to a stop before the swap is made.

 

 

Whether or not you use common return, cab control, split potential or anything else, you do need to make sure that you don't inadvertently introduce shorts on your track. From your description you may, unfortunately,  have done exactly that. Good practice is to put gaps (insulated rail joiners) on all four rails at the frog end of every point, and at both ends of every diamond or slip irrespective of any other gaps that you add for section switching. Then make sure that you connect the correct wire to the correct rail every time. It looks as though one side of your layout is against a wall and you can only control it from the opposite side. Mine is similar. I use two colours, red and black, and the further-away rail is always black - "Black is back" is my reminder.

 

There's no need to stop every train when you move from one controller to another by the way.

[Demondrille Junction]

29 minutes ago, St Enodoc said:

you do need to make sure that you don't inadvertently introduce shorts on your track. From your description you may, unfortunately,  have done exactly that.

 

This is true, I should explain that it was intentional so far as I have curved many of the points and crossings to replicate the prototype track plan. When I tried some plastic rail joiners they weren't strong enough to hold the modified crossing and point rails in place which would try to spring back to their normal shape somewhat and I didn't like their gaps at uniform spots.  Soldering everything first helped me greatly getting the geometry flowing and lined up plus the staggered gaps added later kind of looks better without being as obvious.  Track is Peco 75 and with say 3 large points paralleled diverging to the branch line the joins kind of looked settracky.  I wish I could show a before and after.  I do have a couple of other but not so dramatic examples though.

 

The first pic shows a trailing crossover. Admittedly the middle joins could've been closer there but at this spot I did use insul joiners. The other legs of the frogs will be cut further away from the original joins which have been soldered with shortened metal rail joiners.

 

Second pic shows a trailing crossing with all joins soldered with shortened metal joiners and insulation cuts placed further away from the middle join.  The cuts for the frogs' outer legs are off screen. It makes the track look more continuous IMO. I'm trialling some paints at the moment hence the blur and not so clean rail heads.

 

Owing to the initial soldering of everything, only small sections are currently powered with obvious conflicts gapped and isolated.  I'm slowly working out the rest.  Another issue will be as we down south head towards summer, gapping alone wont ensure electrical isolation which is where I'll be adding plastic shims and cutting in expansion joints which will be jumpered.

 

I do get your points though and very much agree, particularly the bit about putting gaps in irrespective of any other gaps added for section switching. I wasn't going to do all of them but I'm finding it far easier to work things out by doing so. And yes the rear of the layout is practically against a wall but still accessible. I do like the "back is black" adage.  It's not too late for me to change. I went red is back and blue is near and arrgh, nothing rhymes. Unfortunately whilst I tried to keep blue (-ve) towards the front, I've managed to solder some droppers on points back to front and never fixed it. The only constant colour coding I've managed to uphold is green frogs which is obvious.

[AndyID]

Red at rear.

Blue to you.

?

Edited July 26, 2019 by AndyID

[meil]

On 24/07/2019 at 21:44, Clive Mortimore said:

And what does this say?

 

http://www.gaugemaster.com/instructions/GMTFK12.pdf

That does not say what you think it says. That is nothing to do with common return - that warning is to do with not to connecting transforms in parallel on the supply side.

[Clive Mortimore]

7 hours ago, kevinlms said:

Its been pointed out earlier in the thread that what you are doing is not wrong.

 

Please stop suggesting that anyone is saying so.

Oh yeah!

 

1 hour ago, meil said:

That does not say what you think it says. That is nothing to do with common return - that warning is to do with not to connecting transforms in parallel on the supply side.

 

Go back a few post , the bloke who designed Gaugemaster controllers said "do not use common return". Why? There must be something he knows about them which the experts are not clocking on to.

[Sol]

11 minutes ago, Clive Mortimore said:

Oh yeah!

 

 

Go back a few post , the bloke who designed Gaugemaster controllers said "do not use common return". Why? There must be something he knows about them which the experts are not clocking on to.

 If the designer is still alive ( and reading your words Clive which I have underlined, he is )  so why not ask him what is wrong with Common return.

As I have said, it was used in telephone exchanges and many others situations in real life with Mother Earth as the common.

[kevinlms]

1 hour ago, Clive Mortimore said:

Oh yeah!

 

 

Go back a few post , the bloke who designed Gaugemaster controllers said "do not use common return". Why? There must be something he knows about them which the experts are not clocking on to.

But the Model D specifically says that it is suitable for Common Return. I think your information is well out of date.