Full Ring Bus or break it?

[Chrissaf]

Just to add to what Fishy has stated. In electrical circuits, resistance ®, inductance (L) and capacitance © impact on the speed of transmission. Purely as an analogy. Walk along the beach in free air and you could cover 3 miles an hour with little effort. Now try the same in the sea, chest high in water. In my analogy, the water is the effect of R, L & C.

.

OK, the speed in electrical circuits is stil fast, but not necessarily near the 'speed of light'.

.

The effect of L & C on a transmission circuit also has an affect on signal phase regardless of speed. The longer the Bus, the more L & C there is. Thus you can get phase distortion on transmission lines far shorter than a mathematical model based just upon 'speed of light' calculations.

[poliss]

I never said it was the speed of light. I said almost the speed of light.

Do I have to complicate things by explaining why there's no such thing as a DCC signal? That's why I always put 'signal' in inverted commas.

[St1ngr4y]

 

I know the EU have completely different rules, but so far their bureaucracy hasn't impacted yet AFAIK on UK electricals else we would probably have to standardise on the Euro plug. Heaven help us if we do.

.

Roll on June 23rd.

They'll be wanting us to drive on the right-hand side of the road next  😮

Ray

[Chrissaf]

Do Eurostar trains cross over tracks at the Chunnel half way point?  😉

[Fishmanoz]

Why no signal poliss?

[96RAF]

@Ray

They be wanting us to drive on the right hand side of the road next..

 

 

Out here there are flashing signs many and several miles (kilometres) inland of the ports and airports reminding people to 'Drive on the Left'.

 

How they would ever get to read these signs if they had been on the wrong side up to now I have no idea.

 

There again they tend to drive in the shade if they can, mobile phone and cigarettes permitting, whilst hanging a U turn at the lights where the no U turn sign is plain to see.........

 

@FB

 

...European ...

Our electric string in Cyprus is UK based (plugs and sockets, voltage, frquency,  etc), but my house is 3-phase except I have no idea what is on which phase as its all lumped in the main breaker board.

 

I even have all the wiring installed for storage rads but no fixed outlet boxes installed at the room end nor CBs at the panel end, just the miles of wiring all waiting fo me to connect it at both ends. How do I know which bus is which phase in the unlikely event I want to balance phases.

 

Our only good point is they install copious amounts of 1" plastic conduit from all points east to west to north to south so feeding in extra wires using a 'mouse' is a breeze of a job, unlike UK where it all tends to be plastered in at birth.

[poliss]

Why no signal poliss?

Because the alternating current transmits the power and data. There is no seperate 'signal'.

http://www.dccwiki.com/DCC_Power

[Fishmanoz]

By the end of the first para of your reference, signal has been used 3 times.  Just because DCC transmits power and data in the same waveform doesn't make it any less of a signal to me.

 

Then you know all this poliss so why are you trying to make the distinction?

[96RAF]

@Fishy and polis

 

If you read the first para of that link it clearly states:

"...puts a 100% digital SIGNAL on the rails and derives power and data from the same digital SIGNAL..."

 

How clear do you want it. The one who is saying there is no signal is the one who is providing the proof that there definitely is.

[Augustus Caesar]

Hey haway man... settle doon lads... 😎

I had no idea we would be talking ring mains in homes, industry, France, Cyprus or elsewhere when I asked this poser at the start of this thread.

However, it IS very interesting to say the least. I had no idea too that we may be on the hit list for Europe where our ring mains may be banned!! Can they not leave well alone? Imagine the chaos across the country... now this WOULD bring a Brexit!!!

 

Back to the original Q though... and a subsequent query following on from that.

From start to finish as far as my own ring bus is concerned it would be no longer than 28 feet or just short of 9 metres. So the question is: does this constitute a 'large' layout? I think not maybe... but do all the droppers have to be taken into account or is it just the main bus wires when calculating load? The latter maybe?

[96RAF]

@AC - is the moon made of green cheese or is it a Yorkshire pudding - the chances of a proper answer at these odds is probably the same - no chance.

 

 

[mjb1961]

Hey haway man... settle doon lads... 😎

I had no idea we would be talking ring mains in homes, industry, France, Cyprus or elsewhere when I asked this poser at the start of this thread.

However, it IS very interesting to say the least. I had no idea too that we may be on the hit list for Europe where our ring mains may be banned!! Can they not leave well alone? Imagine the chaos across the country... now this WOULD bring a Brexit!!!

 

Back to the original Q though... and a subsequent query following on from that.

From start to finish as far as my own ring bus is concerned it would be no longer than 28 feet or just short of 9 metres. So the question is: does this constitute a 'large' layout? I think not maybe... but do all the droppers have to be taken into account or is it just the main bus wires when calculating load? The latter maybe?

Hi ,I don't know what the other guys are on about ,the way it's going you will have to get a sparky to connect your controller and give you a certificate !,,,anyway my layout is 10ft X 6ft ,so I suppose you could say the bus wire is 32 ft but to be honest it is more like 20 ft ,I have two ovals connected to one bus wire ,there is 16 sets of droppers and it is all connected to the bus wire via electrical blocks ( you buy them in a strip and separate them ),one end of the bus wire ends up being connected to the other and that's it ,then one set of wires come from the controller and is wired into the closest electrical block ,and all works a treat ,I hope this gives you an idea of all that is required with a layout of your size ,,,,,,,good luck 

[poliss]

@Fishy and polis

 

If you read the first para of that link it clearly states:

"...puts a 100% digital SIGNAL on the rails and derives power and data from the same digital SIGNAL..."

 

How clear do you want it. The one who is saying there is no signal is the one who is providing the proof that there definitely is.

It also says +/- 12 volts, which is wrong too. It was the only link I had handy at the time. There are better ones. When you're dragged off to restring curtains you'd post the first link you found too. 😆

I don't like using the word 'signal' because it implies that there is a seperate DCC signal superimposed onto the AC power, and there isn't.

[poliss]

Hey haway man... settle doon lads... 😎

I had no idea we would be talking ring mains in homes, industry, France, Cyprus or elsewhere when I asked this poser at the start of this thread.

However, it IS very interesting to say the least. I had no idea too that we may be on the hit list for Europe where our ring mains may be banned!! Can they not leave well alone? Imagine the chaos across the country... now this WOULD bring a Brexit!!!

 

Back to the original Q though... and a subsequent query following on from that.

From start to finish as far as my own ring bus is concerned it would be no longer than 28 feet or just short of 9 metres. So the question is: does this constitute a 'large' layout? I think not maybe... but do all the droppers have to be taken into account or is it just the main bus wires when calculating load? The latter maybe?

A large layout is defined by Mark Gurries as  'a small 2 car garage (300 SqFt) and it goes up from there'

https://sites.google.com/site/markgurries/home/dcc-general-best-practices/wiring-planing/what-is-a-large-layout

[2e0dtoeric]

They be wanting us to drive on the right hand side of the road next.

Haven't you heard, - from August 1st this year, cars have to drive on the right (Euro) side of the road. HGV's will drive on the right side commencing Sept 2nd.

[poliss]

Sweden swapped sides. They used to drive on the left.

[Chrissaf]

from August 1st this year, cars have to drive on the right (Euro) side of the road. HGV's will drive on the right side commencing Sept 2nd.

.

Does this mean a month of head on collisions !!  😮

[poliss]

No, because the road will bne blocked after the first one.

[Augustus Caesar]

Oh no... we're on to right and wrong sides of the roads, collisions (not the hadron type thankfully), Swedes swapping (isn't that just normal) and more... 😆

[Augustus Caesar]

@mjb

Got ya in terms of your dimensions etc. I'll take that into account... the blocks you mention I already have so no problems there... thanks for your guideline which will be useful.

 

@poliss

Mark's large layout link you give also says this at the end of the page...

"Such layouts can start to have track bus wire runs longer than 30Ft which is the beginning point at which problems can start to appear.  Clearly there are those that claim they have long bus runs and have no problems.  The problem with such statements are: 1) Each Layout is wired differently.  The quality of the wire and installation will vary greatly along with the routing and bundling (intentional or not) of various wires together.  It is as unique as the individual who built it. 2) Most people do NOT know what to look for in terms of potential electrical problems.  If it runs, it must be OK....wrong." Therefore I am within the disaster area of 30 feet, which is pleasing.Number 1 I wil skip but number 2 surely is his own interpretation and may well be right also. But, "if it runs, it must be OK"... well, that's what we are debating here surely isn't it. So what are the potential problems if under that stated 30 feet above if any? By those words it seems to me that my layout in particular should be OK with a full ring bus?

[Fishmanoz]

The reason for the non-definitive answer has already been covered by Chris and relates to stray capacitance and inductance interfering with the DCC signals.  These become more significant the longer the bus but are also dependent on the actual configuration of the wiring used so will differ from layout to layout.  Then there is also the environment around the layout which may have higher or lower levels of interference which may or may not be picked up by the bus in its particular configuration.

 

So while Mark suggests a bus may not be performing correctly, even though the non-savvy user thinks it is, the first order answer will be that if it doesn't appear to be broke, it likely isn't. 

[Fishmanoz]

Poliss, I would suggest the DCC signal packets are most definitely superimposed on the base 12-15kHz square wave that is the power transmission method.  If they weren't, there would be no packets, no signal and nothing to tell decoders what to do.  The only way to get them there is to modulate the base square wave and this modulation is the DCC signal.

 

If instead of thinking of it as a square wave being produced in time, we look at it in the frequency spectrum, what you will find without any signal packets is a large frequency component at the base say 12kHz and other components all at various harmonics of 12kHz (ie. 24, 36, 48kHz etc), decreasing in magnitude the higher the harmonic.  As soon as you put a DCC packet on there, a whole new set of components appear at other frequencies above 12kHz and not being harmonics of 12.  These are the signal.

 

If that is unclear, try googling time domain and frequency domain and you should come up with some simple diagrams that explain the theory.  LaPlace transformation would be another way of finding it, but ignore the calculus, just look for the diagrams showing signals in time and frequency domains.  Chris will probably have a good link for us in no time flat as well (no time flat, good one, no time and we must be in the frequency domain!).

[poliss]

Look at the diagrams. They show you how it works. Seems simple enough to me. My analogy would be that it's similar to Morse Code, including the sending and recieving equipment.

[Fishmanoz]

Morse is of course a signal, manually modulated onto a carrier by the key, so, analogous to Morse, analogous to a signal.

[Augustus Caesar]

Thanks for the clarification Fishy... you reminded me of what Chris had said earlier so I went back over it. 😎

 

My vision is much clearer now and so the debate on 'signal' or not a 'signal' may continue unabated but with a reading interest from this member... 🤐

 

For all the help given I thank thee all... :-)