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DC wiring Block control or conventional isolating sections


Junctionmad
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 one controller per track system ( have we a name for that ?) 

 

 

That's an interesting question. We could think of something but it would probably not be understood outside of this thread...except in your club presentation!

One Controller per Track ...OCT.

One Controller per Section...OCS

Permanently Assigned to Section... PAS

COnnected Directly to Section.... CODS.

 

I think I like the last one but since you started the discussion, maybe you should choose?

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People seem to be getting hung up about terms here. Quite simply you design a layout, you work out how you want to operate it and then design an appropriate control panel - it's a simple as that. Don't worry about what you call it, just build something that meets your needs.

Regarding common return or not. In simple terms we are talking electrical circuits. The start and finish piont for each circuit is s separate feed from the 240 volt to 12 volt transformer. These circuits can share some of the wires in the circuit with other circuits without problem. Common return is an accepted (but perhaps confusing) term for circuits sharing some of the same wiring.

Edited by Chris M
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Actually the practice of returning currents from isolated power sources including AC and DC

People seem to be getting hung up about terms here. Quite simply you design a layout, you work out how you want to operate it and then design an appropriate control panel - it's a simple as that. Don't worry about what you call it, just build something that meets your needs.

Regarding common return or not. In simple terms we are talking electrical circuits. The start and finish piont for each circuit is s separate feed from the 240 volt to 12 volt transformer. These circuits can share some of the wires in the circuit with other circuits without problem. Common return is an accepted (but perhaps confusing) term for circuits sharing some of the same wiring.

Actually , the practice of returning multiple currents from isolated sources is rarely used elsewhere, and hence the term " common return " is not used outside of model railway parlance and in fact most people only use it in conjunction with track section returns. Elsewhere its largely unheard of.

 

I would also suggest that where you have electronics on the layout you refrain from running that dc return current in the " common return" and return it separately. This ensures the noise floor remains low on that circuit

 

So just like in " sense " there little " common ' in " common return "

 

As to your other plaintive cry , the issue is fine for the " cognoscenti " who understand the various wiring schemes etc , many modellers do not understand all the possible options and the issues need discussion and explanation

Edited by Junctionmad
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People seem to be getting hung up about terms here. Quite simply you design a layout, you work out how you want to operate it and then design an appropriate control panel

I am not sure if have been following from the start but the OP was considering doing a presentation to his club on cab control, because few people there use it.

Introducing a term for 'non-cab' control was just an aid to describe the differences.

 

Common return seemed to be a tangent.

Edited by Pete the Elaner
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I am not sure if have been following from the start but the OP was considering doing a presentation to his club on cab control, because few people there use it.

Introducing a term for 'non-cab' control was just an aid to describe the differences.

 

Common return seemed to be a tangent.

Correct and yes CR is a tangent , but people considering it need to understand the key issue

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That's an interesting question. We could think of something but it would probably not be understood outside of this thread...except in your club presentation!

One Controller per Track ...OCT.

One Controller per Section...OCS

Permanently Assigned to Section... PAS

COnnected Directly to Section.... CODS.

 

I think I like the last one but since you started the discussion, maybe you should choose?

I like OCS-PAS , why have one TLA when you can have two
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Actually the practice of returning currents from isolated power sources including AC and DC Actually , the practice of returning multiple currents from isolated sources is rarely used elsewhere, and hence the term " common return " is not used outside of model railway parlance and in fact most people only use it in conjunction with track section returns. Elsewhere its largely unheard of.

 

I would also suggest that where you have electronics on the layout you refrain from running that dc return current in the " common return" and return it separately. This ensures the noise floor remains low on that circuit

 

So just like in " sense " there little " common ' in " common return "

 

As to your other plaintive cry , the issue is fine for the " cognoscenti " who understand the various wiring schemes etc , many modellers do not understand all the possible options and the issues need discussion and explanation

 

 

Common return;  common ground,  the various names mean the same thing - a common wire or equivalent used for various power supplies. Yes electronics may get affected - the hobby is so experimental  that we learn things each day and by exposing what to some modellers is new info , can only be for the better for most of us.

 

Yes there are some who don't want to try out new practices.

 

DC cab control is one practice which to me is perfect for multiple controllers & operators even though I have converted to DCC for a far simpler operating process. My main station can have 4 trains/4 operators on the move at the same time and I would not like to do this in DC.

 

Google dc cab control wiring   and you will find thousands of web pages with info about it.

 

To me. don't knock it until you try it

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Common return; common ground, the various names mean the same thing - a common wire or equivalent used for various power supplies. Yes electronics may get affected - the hobby is so experimental that we learn things each day and by exposing what to some modellers is new info , can only be for the better for most of us.

 

Yes there are some who don't want to try out new practices.

 

DC cab control is one practice which to me is perfect for multiple controllers & operators even though I have converted to DCC for a far simpler operating process. My main station can have 4 trains/4 operators on the move at the same time and I would not like to do this in DC.

 

Google dc cab control wiring and you will find thousands of web pages with info about it.

 

To me. don't knock it until you try it

Oh you mis-understand me. I've used it and I've wired other people's layouts for it.

 

Personally I'm now firmly in the DCC camp

 

NOTE common return is NOT the same as common ground, common ground is a term widely used in electronics and almost exclusively refers to non isolated supplies ( which while sharing a common return , don't actually share a common ground !)

Edited by Junctionmad
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Actually the practice of returning currents from isolated power sources including AC and DC Actually , the practice of returning multiple currents from isolated sources is rarely used elsewhere,

 

Except that it's used all the time.

 

Poly-phase power distribution systems have a neutral conductor precisely for that reason. The National Grid would collapse without them.

 

Sigh.

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I was under the impression that the Duette had a single transformer with dual secondary windings, making it suitable for CR. It's a long time since I saw inside one though.

 

Yes, I believe that is the case.

 

It's not even necessary to have independent transformers or independent secondary wingdings for CR. You can use a single centre-tapped 24 volt PSU and let the controllers swing their outputs positive or negative relative to the centre-tap. That also means the controllers do not need forward/reverse switches.

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Yes, I believe that is the case.

 

It's not even necessary to have independent transformers or independent secondary wingdings for CR. You can use a single centre-tapped 24 volt PSU and let the controllers swing their outputs positive or negative relative to the centre-tap. That also means the controllers do not need forward/reverse switches.

Careful. That's getting into the split potential area and that's really going to upset people. :D

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a method used by the late Rev Edward Beal on his famous West Midland railway in the 1940-1950's combined with Cab Control

 

 

Yes Ron

There are some extracts here from the Rev Edward Beal's 'West Midlands'.  I was given a copy in the 1960s and it has acted as an inspiration ever since.

 

Regards

 

Ray

 

I've got a couple of books from the late 1940s which go into considerable detail regarding split potential so I assume that it was, if not standard, at least fairly common practice. It took me a couple of reads to get my head around it but, having done so, it makes considerable sense, especially if you're wiring a layout without benefit of modern semiconductors or, indeed, ready made controllers.

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I've got a couple of books from the late 1940s which go into considerable detail regarding split potential so I assume that it was, if not standard, at least fairly common practice. 

 

There were early DCC booster designs (I'm talking NMRA DCC, not earlier schemes) that used split potential with one rail tied to 0V and one switched between the +/- rails.

 

There was even someone using a HiFi Amp as a booster :O

 

Andrew

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a method used by the late Rev Edward Beal on his famous West Midland railway in the 1940-1950's combined with Cab Control

I have some of a series of booklets by Edward Beal, the Railway Modelling Series.

 

Book 7 is titled 'Two-Rail Control'. I've just taken a look & found it to be rather confusing. There are many drawings (to quite small scale), depicting lots of different track formations and their wiring options.

 

I have to say, the style of writing puts me off and I have a reasonable understanding of how to wire layouts.

 

 

A quote from page 9.

 

Besides these 2 methods - the insulated & the integral frog - there are and have been many others. It is proposed, however, not to deal with them in this handbook in order that complications and needless words may be avoided. The integral frog method decidedly lends itself in a remarkable manner to the simplification of the whole system, and when intricate formations are required it may be said to wipe out instantly half the possible difficulties and labour. It ought, however, to be said that none of the schemes so far evolved, and none in this handbook, have any claims to be restrictive. There is an unlimited scope, before the investigator who cares to devote time and study to the subject."

 

Sorry, but this isn't technical writing and is just rambling on about very little. Perhaps its the way people of his time wrote, but sadly does nothing for me. The space would have been better taken up with bigger drawings.

 

Edit to add missing word!

Edited by kevinlms
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I agree Kevin, takes some reading...

 

I found this helpful  https://www.amazon.com/How-Wire-Your-Model-Railroad/dp/0890245118    sadly I passed my copy on and and never got it back

 

Outside of this

http://brian-lambert.co.uk/Electrical.html

 

this is another interesting site

http://www.building-your-model-railroad.com/model-railroad-wiring.html

 

and one from UK

http://urlibrary.co/download/how-to-wire-your-model-railroad.pdf

 

so much info on the internet...

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Mayberry there is the need for a new topic where members show how they control their dc layout and why they chose to do it the way they did. I'm involved in 5 dc layouts and the control system for each one is quite different in order to suit the needs of the layout.

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Except that it's used all the time.

 

Poly-phase power distribution systems have a neutral conductor precisely for that reason. The National Grid would collapse without them.

 

Sigh.

Oh for goodness sake. Context context, mine where made in the context of low voltage ac/dc Edited by Junctionmad
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