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Modelling tips & Model Railway Controls Guide

Lumsdonia Railway

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A guide how to make your own cheap Universal Throttle panel

Make your own UTP Guide

UTP Sockets

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An anatomy

I will use NCE control on my layout and want 4 plug in points for controllers, so will need UTP 524-207 face plate that has two RJ12 at the front and 2 at the back that are all parallel connected. They cost £18+ each. Being a skin flint and an Electrical Eng, I will make my own.

I could use a two way face plate and two RJ12 modules and wire Ethernet CAT5 wire to the back of them {thus saving expensive premade "special" RJ12 leads}, but although this type of connector is common in Europe and US, its not here in UK. Import P&P cost prohibit me getting them from abroad {even though they are very cheap over there}. They are available in UK as a RJ12 insert module for structured cabling systems, but would work out at £3.50 a pop! (x2 plus back box cost = £8+). The irony is I have loads of RJ45 (Cat5) surface mount wall sockets that would be ideal. So are free to me (and would be much cheaper for others to buy as RJ45 [Ethernet] is common and therefore cheaper)

[Example http://www.ebay.co.uk/itm/4-x-Double-Socket-RJ45-Cat5E-Face-Plates-Back-Boxes/200501132617?rt=nc] (that would give 4 plug in points each with two controllers)

The odd thing is, that RJ12 male ends actually fit into a RJ45 socket! [6pin into 8pin].I have tried it and it works fine! (metered wires, so connects electrically as well as mechanically)

There is a swivel device available for phone handsets to stop the coil from kinking, it will be a 4 wire RJ22, but my guess is it would fit in a Cab and Cabs only use 4 of the 6 wires anyway!


So we will need the RJ12 lead to connect to command centre, then terminate in a single back box with IDC, some single wires to bridge across the two sockets, then standard Ethernet cable from the second socket out of the back box and on to the next double socket, etc

We can even wire up a LED and resistor and have "power" indication the same as the NCE UTP!


Obviously you get one with the command station and if you just want a second, buying another is certainly simpler and not much money, but if like me, you have a large layout and say want 3-5 points, this will save over £100

Fig. 1 and 2 show the simplest configuration, but if you want you can have LED’s (see Fig. 3 and 4) and on very long runs can double the wiring for less volt drop (see Fig. 5 and 6)

Fig. 1    UTP Cab control wiring START

Fig. 3    UTP Cab control wiring START with LED and External 12V

Fig. 4    UTP Cab control wiring MIDDLE with LED

Fig. 5    UTP Cab control wiring START with LED and Double

Fig. 6    UTP Cab control wiring END with LED and Double

Fig. 2    UTP Cab control wiring MIDDLE

An LED can be added to all, at the position shown, it will indicate Command power, on first socket and aux power, on all the others. Note one cross connector is missing (Green) if Aux power is added

If you have 3 or more sockets, Fig. 4 shows the middle ones wiring

If you have 3 or more sockets, Fig. 2 shows the middle ones wiring. The end socket just does not have a wire leaving on the right

IF the run required is say over 10m, you can double up the cables, shown as violet links in first and last sockets. Fig 5 (7 & 8 and 1 & 2 can be joined for very long runs)

If the run required is say over 10m, you can double up the cables, shown as violet links in first and last sockets Fig. 6

I have not shown a drawing for the terminator circuit, reason is, that it is not required, only applicable if layout is massive (club) or you specifically have RFI issues.

[I am also confused by the fact that I know the NCE BUS is RS485, and yet the NCE drawing shows a Canbus power snubber!]

Fig. 1 shows the first socket wiring for the simplest version

Numbers in brackets are the cab wire numbers

Supply list

For each box:-

2 x RJ45 Module

1 x Double Module facia

1 x Single backbox


1 x Double Ethernet socket

1 x Single backbox

CAT5 Ethernet cable

IFC tool (or careful use of small screwdriver)

Aux 12V DC should only be used if replacing NCE UTP in conjunction with PowerCab

UTP = Universal Throttle Panel

{Not to be confused with an Ethernet wire term which means “Unshielded Twisted Pair”

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