240 v Mains cable

[Gordon H]

I suppose it might help if I come clean on what I am trying to do. But am I hijacking my own thread?

I have available the Aristocraft HO controller system. This is a radio control. Not DCC. The system requires a 12 volt dc supply.

However I wonder if an ac supply of about 16v rms converted in the loco thru a bridge rectifier before feeding the aristocraft radio controlled chip might be a better,or simpler way of supplying the necessary power. The controller is hand held and wireless. So I reckon I need a 4 or 5 amp steady supply of approx. 12v. If I use ac I think loops etc. will be much easier to wire.

I would suggest you will need a smoothing capacitor at least, if not full regulation, after the bridge rectifier to ensure that the radio system works properly. It will have been designed with an essentially constant voltage, low impedance local battery source in mind, and may be uncomfortable with the kind of supply variation you are likely to get via a conventional track pick-up system unless it is designed to present a similar source to the circuitry.

Also, four or five amps seems very high for any HO scale loco. Many Gauge 1 radio controlled locos of my acquaintance don't draw anything like that level of current - more like one or two typically.

Of course, if you are expecting to use multiple radio controlled locos on the same track, as per DCC, that observation is void - though one might question the relative cost of using a radio system instead of DCC for such a set-up.

That said, I myself have a radio controlled OO Class 56, fitted with track pick-up, which will work with essentially any power source (including DCC), but that does provide power regulation before the radio controller, which is one of those now being produced by Cliff Barker for mainly Gauge 1 users.

[Crosland]

There seems to be a lot of confusion about amps volts and watts on the posts on RM web as this sort of thing has cropped up before.

Indeed. The power being discussed is largely irrelevant as it is the power consumed by the load and not the cable. The critical parameters for cable are the voltage drop at a given current. For example 2V drop at a given current in a 240V system is a lot less important than 2V drop in a 12V system at the same current.

 

Andrew Crosland

[Mallard]

I would suggest you will need a smoothing capacitor at least, if not full regulation, after the bridge rectifier to ensure that the radio system works properly. It will have been designed with an essentially constant voltage, low impedance local battery source in mind, and may be uncomfortable with the kind of supply variation you are likely to get via a conventional track pick-up system unless it is designed to present a similar source to the circuitry.

Also, four or five amps seems very high for any HO scale loco. Many Gauge 1 radio controlled locos of my acquaintance don't draw anything like that level of current - more like one or two typically.

Of course, if you are expecting to use multiple radio controlled locos on the same track, as per DCC, that observation is void - though one might question the relative cost of using a radio system instead of DCC for such a set-up.

That said, I myself have a radio controlled OO Class 56, fitted with track pick-up, which will work with essentially any power source (including DCC), but that does provide power regulation before the radio controller, which is one of those now being produced by Cliff Barker for mainly Gauge 1 users.

 

You sound as though you have read the handbook. I feel power regulation is essential although Aristo-craft say all you need is a good 12v DC supply. You can run as many locos as you like. A five loco consist is quite feasible. Hence 5 amps supply should cover most options and I can't really see me using more than 3 locos on one controller. Double header and a banker up a 1 in 50 helix I have built.

 

In terms of my orginal query I think I will be using the T & E stripped of its outer cover and use the earth wire for droppers.

 

Thanks to everyone for interesting and helpful comment and suggestions.

[Pinkmouse]

Its been the 17th edition since 2008.

 

Yup, but having been out of the live events industry for a while I'm not as familiar with that edition as I am with the 16th.

 

Though I obviously don't know all the circumstances, but presumably you were also using Socapex multipin connectores - I wonder how the NEC Electricians get on with the stage lighting for the likes of Tom Jones, Barbara Streisand, West Life, etc., etc., As I recall a lot of that's done using Socapex cables and connectors, plus of course the 3 round pin IP44 rated (EN 60309-2, IEC 309-2, CEE7) plugs and sockets for individual items. I use these for my layout lighting too.

 

Live events are carried out under different rules, and with different inspectors. Exhibitions fit in a gray area between live event rules and building regs, and most of the electricians involved come more from the building/installation side. It can get very complicated!

[96701]

Just to clarify my use of the T&E (Twin & Earth flat grey) cable for a BUS, I was suggesting using the individual solid wire stripped out of the sheathing, it could just as easily be some brass 1mm square bar/round wire from say Eileen's Emporium, but that would be a lot more expensive and is only available in short lengths.....

 

Yes, you can use copper conductors for powering model trains. Use the live & neutral conductors, the CPC (Earth) is often smaller cross sectional area than the other two.

[Gordon H]

You sound as though you have read the handbook...

No, but these are general principles which apply across the board with this kind of kit.

However, I did design the Cliff Barker version, which is how my Class 56 came to be fitted with it using some old prototype parts.

[Mallard]

No, but these are general principles which apply across the board with this kind of kit.

However, I did design the Cliff Barker version, which is how my Class 56 came to be fitted with it using some old prototype parts.

 

Say no more. However, working in the larger scales does make battery power feasible, and hence makes life much simpler. i.e. No loops or triangles causing polarity problems.

I scratched my head for hours wondering if I could get a 12v battery system into HO outline. Not impossible. But not very practical. Three box cars permantly connected to each loco seemed the only possible way, and that is not what I was looking for. Hence a steady state 12v supply and if I installed a bridge rectifier (with smoothing) to supply the radio contol chip I might get away with everything on the loco. Then I thought with careful rail breaks to avoid short circuits I might be able to run through my triangle without stopping or flicking switches. Because I was thinking rectifiers I was also thinking AC. But your comments have me wondering if DC would work the same way. I need a constant polarity feeding the control radio chip. Am I correct in thinking no matter what the rail polarity is the output from the bridge rectifier would always give the same polarity?.With AC or DC?

You will have realized by now my electronic knowledge is very scant.

 

BobM

[Gordon H]

Am I correct in thinking no matter what the rail polarity is the output from the bridge rectifier would always give the same polarity?.With AC or DC?

Yes.

 

One alternative to batteries that was demonstrated many years ago by MERG founder John Down was the use of so-called 'SuperCaps', which are simply very large value capacitors (typically in the order of one Farad) which are able to keep such circuitry alive for considerable periods, and are ideal for occasional intermittent loss of the track source.

Fundamentally, what is required is an 'Energy Storage Unit' (or ESU) which handles all aspects of charging and output regulation. This is all do-able, but does need a considerable amount of effort to engineer it into the smaller scales.

[Mallard]

Yes.

 

One alternative to batteries that was demonstrated many years ago by MERG founder John Down was the use of so-called 'SuperCaps', which are simply very large value capacitors (typically in the order of one Farad) which are able to keep such circuitry alive for considerable periods, and are ideal for occasional intermittent loss of the track source.

Fundamentally, what is required is an 'Energy Storage Unit' (or ESU) which handles all aspects of charging and output regulation. This is all do-able, but does need a considerable amount of effort to engineer it into the smaller scales.

 

That is one possible problem cleared. Thanks very much for your know how. I have got a bit to think about.

BobM