Mustard tin controller

My friend Les has a habit of building controllers. One of his was built into a Colman's Mustard tin, using a cheap Chinese PWM controller as found on eBay. His design is fed using the 16v AC, from the accessory output common on a lot of model railway controllers. He also made one for me (thanks Les), but I wanted to try my hand at making my own.

These are the parts I used;

And a list;

Kato Unitrack extension lead (to connect to either of my ovals of Kato track, N gauge for testing OO9 locos and HO for the Christmas trainset),

57gram mustard tin,

Adjustable voltage wall-wart (3-12 volts) (wall mounted transformer Seelion brand),

Crocodile clips,

Small cable ties,

Sleeved cable strain relief grommet,

16v 1amp resettable polyswitch fuse (to protect the motor in case of a stall),

Centre off DPDT toggle stitch,

7/0.2 stranded wire in red and black,

12v green pre-wired LED and cap,

Jack plug socket 5.5mm x 2.1mm (to connect to the wall-wart),

Heatshrink.

The first job was to drill the tin, starting at the lid with a 7mm hole for the controller. 6mm holes were drilled in the sides for the LED and toggle switch, then two more holes in the bottom, 8mm for the power socket and 10mm for the strain relief boot;

Next I wired the jack socket, with the LED and two leads to connect to the control board, noting the polarity of the socket;

Onto the control board itself. I found that circuit board was too long at the top, stopping it from being bolted in squarely. Easy fix with a razor saw, the one on the left is as supplied and the one on the right cut down;

With the control attached to the lid it could be wired to the jack socket, no soldering required as the board has clamps rather than pads. It could now be powered up, there's an LED on the board to show if its working;

Next job was to wire up the DPDT switch. I cut the Kato extension lead in half and used the half with the female socket as my output, to connect with my pre-wired Kato track;

Please don't be too critical of my soldering! I'm much happier soldering brass than electrics. Its worth noting that the output wire had to be threaded through the relief boot and tin before being attached to the switch due to the socket on the end.

Next up the polyfuse was soldered to the motor + wire and covered with heatshrink;

Then the switch was wired to the board (which is clearly marked as to what goes where) and the thing tested with a multimeter;

I'm pleased to say that it works rather well. Its been in use on the Christmas trainset, powering a variety of Hornby's cheaper offerings.

Here's the complete unit, with its wall-wart;

The other half of the Kato lead, with the male connector, was used to make a test lead;

My thanks again to Les, who not only built me my first controller but also gave me invaluable advice and encouragement when I made this one. He wrote a thread on the NGRM-online forum describing the build. 

And now the boring bit. I need to point out that I am NOT an electrician or electrical engineer, and this in NOT meant to be a how-to, just a record of how I did a job which may be of interest to others. I used a wall-wart for safety, I'm quite happy messing about with 12v but playing with mains voltage is beyond my skill-set. If you do choose to be inspired by this and build your own, you do so at your own risk, if in doubt get help. I really hate having to type this, I believe that those who read my writings are sane sensible adults, but this is the world we live in.

Paul.