Building a Powerbox - Part 3. More switches and sockets

 

One feature I've always built in to my layouts is an extra direction switch below the controller socket. 

You see, I'm not that good at making sure my kit built locos all operate the same direction when you drive them, and since it's easier if the switch on the controller is matched to the direction of travel, the extra one sorts this out. 

I'd like to say I note those models running reversed and swap the motor wires when back at home, but I'm usually more interested in doing something else. Besides, I have a switch, so I might as well use it. 

From my electronic bits drawer, I found a nice chunky slide switch and wired it in. I like chunky switches, they are so much more satisfying to use. 

This one has a centre off, which has already caught me out once, but I'm sure it's a good idea. 

While the output posts are nice, I thought some chocolate block style versions would be useful as well, and I have some that are pushed to grab/release the wire. 

I know these came from a show because I'd never seen them before and knew there would be useful for something. As well as track power (red and black wires) I've connected the second 16V AC output from the transformer, just in case this is handy one day. 

Finally, the same input that goes to the controller is wired to a chocolate block poking out the side and operated through a couple of holes in the top of the box using a long flat-bladed screwdriver. This isn't an output, but an input. If I don't have access to mains electricity for the transformer, I could feed some 12V DC in here from a lead acid model boat battery. Obviously, not at the same time as the 16V AC is going in, but I made this, I know how it works, so (hopefully) I'll not cock it up. 

There we go. A useful tool made up that I'll hopefully use for many years. There's plenty of space in the box too, if I find more gizmos to add!

Building a Powerbox - Part 2. A pretty, but useless voltmeter

I love light up gizmos, and what better, and potentially more useful, than a voltage readout on the panel? 

Component Shop sell something suitable, but I went down the eBay route as I wanted one with bezel and ordering from weird people was part of the fun of this project. How you can have a business that sells components so cheaply, including minimal or no postage, and make a profit is a mystery. 

Anyway, the meter needs a feed from the track output that is the correct polarity, so it's fed through a tiny bridge rectifier. 

You're supposed to solder these to a circuit board, or some veroboard. Mine floats in mid air, although I have used some heat shrink on many of the connections to both support them, and avoid short circuits if the wires move around.

Track power goes in through the inputs that would normally take the AC power, and it ensures the outputs are always the correct polarity. 

The good news is, the panel lights up and changes value as you twiddle the controller knob. 

The bad news is that according to my old dial multimeter, it's reading 2V too low. Are those volts being lost in the rectifier? I don't know, but I'm not losing much sleep over this, the display is mostly for show anyway. 

You'll notice that I've added a couple of LEDs which hadily tell you when you've reversed the polarity to the track, in case you didn't notice you'd flipped the switch. They are petty though.

Talking of switches, I've added another one...

Building a powerbox - Part 1. Basic ideas

The Problem: I use a Gaugemaster handheld controller and transformer on all my layouts. Both have 5-pin DIN plugs on the end. Handy for the fully wired layout, but no good when I need to test a model on a new product or a rolling road. What I need is something to plug them in to with suitable outputs for the track. 

My solution, the Powerbox. 

16V AC in. Track power out. All controlled from a Gaugemaster handheld. 

The thing is, my favourite section of the old Maplin catalogue was the one full of lights and switches. 

Anyway, the basics: 

I found an old plastic box in the garage and decided to make use of it. In the side, I fitted the transformer input and on the top the controller connection. For the track output, there is a pair of post connections designed for stereo speakers, I think. 

A lot of this stuff came from odd places on eBay. I tried to stick to UK suppliers, but this was being done on the cheap with the risk that stuff bought in might be rubbish. Sadly, I haven't enjoyed an electrical components supplier locally since Maplin, and before them, Tandy, vanished from our high street. Once or two bits are from the stash of electrical items bought at shows though.

The basics are really all I needed, but then the box is quite large, so I added a few extras...

Michael Campbel faced a similar problem and developed a little box to deal with it. Needless to say, I saw this just after I had finished my version.

Beware geeks bearing gifts

Some time ago, I was on the receiving and of a load of chunky plugs and sockets. I love these things as they are far easier to wire up than micro versions from the IT world, and there is something very satisfying about using connections as old as a H&M Duette.

Anyway, as they are getting hard to find, and despite the fact I've not used the last lot, when offered more I said yes.

The box was collected at our show and dropped in the back of the car.

It's only when I got home I realised, THERE ARE NO SOCKETS!

Yes, I have some very nicely assembled wires fitted to some lovely chunky plugs. But nothing to plug them in to.

I suppose the wire will be useful...

Wiring looms

Time to add some wires to Polar Bear. The basic circuit is pretty simple - batteries wired to the motor via a DPDT switch which will handle direction and on/off duties.

There is an added complication that a pair of giant LEDs will be fitted in the ends. These will light up in the direction of travel. Looking at the diagram which is partly neatly drawn but has hand draw extras for this lighting, I can see a few people being confused.

It IS correct, but you need to realise that the long and short legs of the LED aren't the same. They show up on the drawing if you know what you are looking for. There's an extra wire to the switch too.

Once set up, all worked well. Until I put the switch support box back in. Then the loco ran properly in one direction and very slowly in the other. Take the box out and all was well. After a bit of head-scratching, I realised that the box was pushing the LED legs together so when the model worked in one direction, there was a weird short circuit. Pulling the legs around so they no longer touched and all was well.

Spools of wire

Am I the only person who uses wire? It seems so as I picked these up from the Stevenage 2nd hand stall in the middle of Sunday morning. Spools of enamelled wire suitable for winding solenoids, or in my case, using for droppers for track feeds.

To be honest, I just liked the look of the wooden bobbins.

The thicker wire is 0.5mm diameter, the thinner 0.1mm

Both come from The London Electric Wire Company and Smiths Limited. I can't see any dates on the paper labels affixed to the end of the bobbins so this is all I know.

I wonder how old they are? I'm thinking over 50 years, possibly a war surplus item? 

Wiring a battery electric loco

Plan A for the Hunslet involved fitting a cheapo infra-red control system that I picked up at a show. That didn't work, so I've decided to wire it up with a switch for the moment. The bits are in the box with the rest of the kit anyway, so I might as well use them.

Wiring this stuff isn't rocket science. Essentially the batteries are wired to the motor and these make it go.

For stop and reverse, add a double-pole-double-throw switch. Batteries to the middle terminals. Motor attached to the end pair. Then the top left terminal is wired to the bottom right and bottom left to top right. The wires should cross on the middle (make them a bit longer to loop out of the way of the connections to the middle pair.

Hopefully, my crude diagram will help. If not, ignore it.

One fault with the set-up is that the switch provided doesn't have a centre off. Had I spotted this before wiring, I'd have replaced it with one that does. As it is, the slider needs to be carefully positioned in the middle to switch the motor off.

Long term, I want a cheap remote controller - suggestions in the comments please - I am NOT spending Deltang money on this model! As the body is not fixed down, retro fitting shouldn't be a problem.

You can't solder to Hornby track, so how do you get the electricity in?

Phil from in front of a layout he is trying to wire says:

Arghhh!!! I'm trying to solder wires to some old Hornby track and the stuff won't stick. Even with flux, the solder just smears on the surface like toothpaste on a mirror. 

 

Phil answers: Hornby steel track is coated with a lacquer to stop it rusting. I think this applies to both old and new rails - the coating helps keep the track clean (good) but you really need to to use one of the companies proprietary methods of attaching wires to it. Either the R602 power clip or  the more substantial section of track with screw terminals applied with some sets, are the solutions. 

That's fine except where you need lots of feeds. On nickel-silver track I'll happily solder wires to the side in a matter of seconds. Here, it wasn't working. 

After much head scratching, the chap I'm building the layout for reminded me that the local model shop had supplied him with some Peco pre-wired fishplates. 

Perfect! OK, the track had to be lifted and the existing fishplates replaced but the result was very neat and effective. With small holes drilled beside each one, the wires poked below the board, any obvious wire could be painted or covered with ballast. 

Maybe on finescale I'd still prefer solder, the wires don't bend much so you can't route them directly down under the board for total invisibility, but here they were the idea solution to the problem.

Wiring a multi-pin plug

 

I'm making up an inter-baseboard lead for a new project and this involves wiring up a couple of multi-way plugs.

 

Back in the old days, these would have been honking great things that you could have used a blowtorch in. Nowadays we have stuff more suited to being stuffed in the back of a computer than a Lancaster bomber, so the work is more delicate.

 

After much practise, here's my (hopefully) helpful suggestion.

• Tin each wire and then cut the exposed length to the same as the pin to be soldered to.
• Tin the pin.
• Bring the two together and with a tiny bit of extra solder on the iron tip, heat the joint. Take the iron away and let it cool, a matter of a couple of seconds.
•  Tug the wire. If it stays on, the join is probably good.
•  For extra security, you could slip a length of heat-shrink tube on each connection but I'm too lazy for that. A length of insulating tape between the rows of pins is pretty quick though and worthwhile insurance.

It's important to hold the plug/socket securely. A small but heavy hand clamp does the job here but a big blob of Blu-Tack will do if nothing else is available.

Wiring D-connectors

Handy hints for wiring D-plugs and sockets:

1 - Get someone else to do it. Preferably the sort of person who likes this sort of thing.

Seriously, it's a fiddly job better suited to an electrical whizz.

If that's not possible:

1 - Fill each little hollow tube inside the plug/socket with solder.

2 - Tin the wire and then cut it so only 3mm or so is exposed.

3 - Heat the connection and poke the wire into the molten solder. Because both wire and connector have solder on them, you don't need to introduce more to the joint, reducing the number of hands required.

4 - Let the joint cool and then tug the wire. If it doesn't come off, it's probably good.

5 - Scrutinise the joint to make sure mo stands or wire are touching other connections.

6 - Where appropriate, cover the wires with the appropriate plastic covers and use these to plug and unplug things. Never pull on the wires. If you catch someone doing this, stick a soldering iron in their ear. If they keep doing it, switch it on first. Fault finding in these things is a nightmare when an idiot tugs a connection lose. Guess how I know...

Work slowly and methodically with regular tea breaks and it's do-able, just not the most fun in the hobby.

Leads

It was Dave Elbourne who put me on to connecting leads back in the very late 1980s with his layout "Scotland Street Yard".

At the time, model railways layouts tended to be adorned with dangling leads to transfer power from one board to another. While these worked, they were prone to getting caught on things as the model was transported around. Snagging one during set-up could result in a few broken connections and some swift soldering iron work before operation could commence.

Dave worked for BT back in the days when quality and reliability mattered more than all-out profit. Taking his cue from this, and I suspect the easy availability of leftover free connectors, he made up all the layout connections as lead - bundles of wire with a plug on each end.

Sockets were fitted to both layout and control panel and dangling wires were no more.

OK, you could forget the leads and there were twice as many connections to be made but to my mind, the results were an awful lot tidier.

On most of our layouts, I've gone for leads. Only Flockburgh has dangling cables and that's because I used obsolete chunky plugs and sockets and couldn't get enough to make them self-contained. The result is a panel with long bundles of wire floating around that I am always terrified will snag on something.

So far we have been lucky, it can't last, so Edgeworth has leads.