Wiring for cab control with 3 controllers

QUOTE (N Gauge James @ 5 Nov 2008, 05:46) <{POST_SNAPBACK}>Hello all,

I'm coming to producing my wiring diagram for the layout and I'd like to employ some kind of cab control system.

I have a double track loop with a large yard in the centre which can be accessed from both loops...



I want to use three controllers - one for each loop and one for the yard - but want each controller to be able to power all three sections. I have read that this will need some kind of rotary switch so that each set of feeds can either be off, connected to the yard, connected to loop 1 or connected to loop 2.

My question relates to poles/throws etc - I can't seem to get my head around what type of switches I actually need to get.

Many thanks in advance for any advice anyone wants to throw (oops, bad pun) my way!



***Hello James.

Ideally a 2 pole 4 position rotary switch. this would give controller 1, 2, 3 and of course "off" for each section.

regards

Richard

QUOTE (Richard Johnson @ 5 Nov 2008, 02:51) <{POST_SNAPBACK}>***Hello James.

Ideally a 2 pole 4 position rotary switch. this would give controller 1, 2, 3 and of course "off" for each section.

regards

Richard

Instead of rotary switches you could try latched push button switches. I have some 6 DP switch gang that came from an old 5 cab layout.
Ill try and take a photo and upload it later.

Regards,
Peter

QUOTE (Richard Johnson @ 5 Nov 2008, 02:51) <{POST_SNAPBACK}>***Hello James.

Ideally a 2 pole 4 position rotary switch. this would give controller 1, 2, 3 and of course "off" for each section.

regards

Richard

Thank you Richard - I'm off to look for some now.

LF - I have considered making the move to DCC several times, but as I would have to get my locos chipped by someone capable and replace my extensive DC control gear, the cost is somewhat prohibitive in what is already a expensive scale.

Hi James

This has absolutely nothing to do with your question - please ignore it if you so wish.

Reading your post, particularly the piece about the yard being accessible from both loops, the one thing that hit me immediately was you cannot get directly into the yard from the inner loop without 'setting back' or reversing into it. (I'm assuming here that as the layout is 'Coleshill' it is a Brit based operation where you drive on the left).

Have you considered having an arrival road? This could be easily accommodated with a small extension from what I think is your fiddle yard and is crying out for a little bit more track. (the blue piece in the diagram)



Having done that, you could then possibly go on to easily create a full inner loop (the green piece in the diagram)



Being conscious of spending money (who isn't nowadays) the extra trackage wouldn't be too expensive but the added operational interest would be tremendous. I suppose having put in an inner loop you might start thinking about four controllers so it may work out expensive in the end.

As I say, nothing to do with your question so please ignore me.

Mike

James - most readily available rotary switches have twelve contacts so you end up with:
2 pole 6 position
3 pole 4 position
4 pole 3 position
as the variations you are most likely to come across. The 3pole 4position is the one that will do what you want to do.

If your controllers are all independent of each other, ie each has its own transformer or winding on a transformer powering it, you can save a lot of wiring by using the 'Common Return' system. In this all the 'inner' rails (say) of each ring of track are linked together and connected to one output terminal of each controller also connected together. The remaining output of each controller goes to the switch for each section and a single wire runs to the outer rail (say) of that particular section. This cuts the amount of wire and connections by nearly half compared to running a pair of wires to each separate section.

Regards,
John Webb

QUOTE (John Webb @ 6 Nov 2008, 19:01) <{POST_SNAPBACK}>James - most readily available rotary switches have twelve contacts so you end up with:
2 pole 6 position
3 pole 4 position
4 pole 3 position
as the variations you are most likely to come across. The 3pole 4position is the one that will do what you want to do.

If your controllers are all independent of each other, ie each has its own transformer or winding on a transformer powering it, you can save a lot of wiring by using the 'Common Return' system. In this all the 'inner' rails (say) of each ring of track are linked together and connected to one output terminal of each controller also connected together. The remaining output of each controller goes to the switch for each section and a single wire runs to the outer rail (say) of that particular section. This cuts the amount of wire and connections by nearly half compared to running a pair of wires to each separate section.

Regards,
John Webb

*** Hi John

You are dead right on the switches.... now they make only one or two styles which are flexible in configuration. Actually there may be a benefit to the 3rd terminal - if James wants to add lights to show which controller is connected, he can share one terminal with a separate power supply and use that plus the third to light a LED - an old mobile phnoe charger would be ideal for that..... easily done.

Re common rail.... I don't often disagree with you on anything but do on this one! Its time has passed.

Yes, it is the traditional wiring way however only ever in the UK, where area control (separate controllers for each area of the layout) has always been common. In most other places totally separated cabs with 2 wire connection and connectable to any area of the layout for progressive cab control are normally used .

I'm aware this is stated as a DC layout but that is now... and layouts can have long life.

If you use one common rail it will give potential for problems later if the layout is ever to be converted to DCC. It also removes much of the potential flexibility for DC or DCC track detection circuitry and the like. I also don't even see it as much wiring saved if a thourough job is done.. I say that as for reliable wiring you need to run wire to quite a few places on the common side anyway, so very few metres are eventually saved!

For those reasons (even in the dim distant pre DCC past) I have always disliked common rail wiring... I see it as a compromise for only a few pennies saved and in time, only a few solder joints.

So... from my point of view, for best long term layout potential, it is much better to use a far more robust approach and stick with two wires to each section

regards

Richard