On my old BEMO RhB H0m layout I built quite a complex control panel and some of the thoughts from that (hopefully the good ones!) I've incorporated into Lynton's requirements.
As the layout is to be "portable" with a view to (maybe) exhibiting at some point, set up time is an important factor. Plugs and sockets for all the connections are an essential and work well. But thinking through everything beforehand pays off later.
This is an account of where I'm at currently.
Rough sketches are very much how I work to achieve the end result. Having decided on the basics, where switches and LEDs are the preferred method of control and indication (the layout is designed for either analogue or digital), I doodled up to the point of "this looks feasible".
The box to house everything was constructed having worked out the size needed. I had a piece of perspex, which would be the "face" of the control panel, which then actually dictated the size! In practice it worked out perfectly.
The box with the perspex panel.
Routing the edges to allow the perspex panel to sit flush with box front.
How the panel fits - rounded corners.
Before painting the box and showing the printed layout which is glued to the back of the perspex. I had to experiment on small pieces to find the right glue. Eventually used Scotch Super 77 Multi-purpose spray adhesive. I used a light spray held about 12" away sprayed quickly to stop any blobs. Even so there were a very few small blobs, but they are very hard to see.
The perspex was centre punched where every hole had to be and having carefully selected the right drills for the various switches & LED holders carefully drilled - slowly - otherwise the perspex started to melt. A really long and tiring job.
All the hardware fitted.
Designing the circuitry for how the LEDs would be connected to ensure the correct colour was displayed for the indicated function. Red for no circuit. Green for DC supply. Blue for DCC supply (a future possibility). It requires 5x2 pole changeover relays (5 volt sub-miniature) for each point/switch. This took some months to get my brain around all the connections. The left-hand sketch shows how I arrived at the solution and the right-hand nice neat interpretation block diagram converts the sketch into how the relays fit onto the printed circuit board. I can get relays for 2 points onto 1 circuit board plus space for another 4 relays, one of which is need for each section switch (12 sections). OK all you DCC fans, I appreciate this might be "simplified", but I didn't want to go through the long learning curve.
The underside of the PC board.
One of the sub-miniature relays. I fitted sockets to enable relays to be plugged in, just in case of failure and needed to be changed.
The printed layout diagram. It was printed on my large format photo printer on heavy high quality photo paper for durability.
The next stages: Wiring up all the section and point switches and LEDS with their respective relay PCBs. Turning the point/signal interlocking sketch diagram into a working system. Fitting the small enclosed 12v and 5v power supply units. Wiring the whole box to the 2x25 pin sockets for connecting to the layout.
I am proposing to use servos for the signals and to open/close the doors on the engine and goods sheds. These will be controlled by a MegaPoints Servo Controller. I researched many different ways to control the servos from currently available systems and the MegaPoints system is the most flexible and programmable - at least from their training videos on YouTube.
That's it for now. Keep watching this blog. - the Station building is progressing slowly! Almost 600 hours into it so far.