Point control panel
- Thread starter Bryan Thatcher
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- point work
And a capacitor discharge unit helps to keep the smoke in
(from my son's HO railway days)
Yeah definitely. I make my own for my N scale layouts, but rather than one big unit I have one for each point motor so I can fire as many points at a time as I like via a diode matrix or whatever. I've made 70+ of these over the last couple of decades!
Trying to get my head round how they would work. On my 0 Gauge Exhibition Layout I used a diode matrix setup for firing up to 5 Point Motors but had a masive 35000 Microfrad Capacitor to get them all fired ok. Problem was when I tried to doube wire them via my Second Control Pannel the length of wiring was just too much for the main power to fire any of the points. Guess that I should have used your system of one for each motor. But how are they wired, does just a return to with the power from the Capacitor make them work or what? Think where I webpnt wrong was in expecting the Main Power to jump the long distance, perhaps may have been OK if I wired the other way round.
JonD
Hi Jon
I use 24vDC. for point power. Each CDU has a 2200 microFarad cap, a power transistor for each point throw direction and sundry resistors and diodes.
I run a power bus around the layout, so each CDU charges from this bus. Doesn't have to be a particularly heavy gauge of wire, just enough to be adequate. Originally I got away with single core telephone wire in the early days! These days I tend to use 16/.02 wire. It takes a few seconds for all the units to fully charge when the layout is switched on.
I take the positive side of this same supply to push buttons on my panels, and then out to the CDUs. Only needs small gauge wire (7/.02 is plenty) as it's just a control signal. My original thinking was to aim for computer control, but in 20 years I've never got round to this! For my fiddle yards I have a single push button for each line, with diode matrix routes firing 7-8 points in some cases. Only needed to use small signal diodes in the matrix.
The only high current wiring is then two short lengths from the CDU to the point motor coils (standard Peco motors).
It's obviously not a cheap approach, but has been faultless since the current layout was built in 1996. When operating at shows we have at least two operators, and we get no conflicts waiting for a single main CDU to recharge.
Nick
PS - I should add my CDUs are designed for twin coil motors not reversing DC types such as LGB/Kato.
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Bought these of Fleabay 
which should be OK if not exposed to the elements
http://www.ebay.co.uk/itm/12x-Point...eco-1stPost-/361389506340?hash=item54247e3f24
which should be OK if not exposed to the elementshttp://www.ebay.co.uk/itm/12x-Point...eco-1stPost-/361389506340?hash=item54247e3f24
Bought these of Fleabay
http://www.ebay.co.uk/itm/12x-Point...eco-1stPost-/361389506340?hash=item54247e3f24
Those are what I used. They are available from various sources, at wildly variable prices. Waterproof covers are available from Maplin (at least).
I've only used a single CDU in a box with the point switch wiring, on the basis that you're only likely to fire one point at once (or possibly a pair on a crossover).
Can't remember the actual wiring now
but I seem to remember that you could wire all your point motor (passing contact) switches with a common return.
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That's just the point Mike. Nick is suggesting firing several at once using his Diode matrix.
How many hands does he have ?
How often do you need to actually fire them 'at once' as opposed to rapid succession (which a single CDU will handle)?
Actually, it doesn't matter - Rule 8 - fire away. It just goes to prove that there's more than one way of killing a cat
My slightly facetious, and attempted funny remark about hand operation, was a solution that was deliberately taken - I simply wanted minimum future maintenance issues - given that, in the first place I had three points on the WWSR and now I have four on the WWNR; phwoar, steady as she blows
We have two or three operators on my N layout, each busy doing his own thing, and the fiddle yards are controlled by single button route selection, so one button push might fire up to 7 points. A single CDU wouldn't cut it.
This is also about not having to carry heavy current over long distances of wiring. Only low current control pulses from the push buttons or diode matrix output (or computer control but I haven't got round to that yet!), and the high current for the point motor coils only travels over 2-4 inches of wire.
It ain't cheap but it works flawlessly! These days with DCC you can also do route selection and fire multiple points very easily, and it's interesting to note there are DCC point motors available with their own built-in CDU (ZTC or Gaugemaster for example), for exactly the same reasons as I came up with my approach 20 odd years ago.
Ah, yes, I can see how it could be desirable, and ideal in the smaller gauges - and especially on an exhibition layout that actually runs trains
I can also see how using the matrix system would cut down on the need for visual mimic boards and track diagrams.
That's the beauty of this 'ere forum, you live and learn
Oh no, deffo still got mimic panels with track diagrams - otherwise where would I put the buttons?!!
The diode matrix just handles routing one button to several points, so instead of two buttons per point in the yard we have one button per track.
For one show I actually forgot the main control panel completely, still managed to run trains for the weekend by frigging the board cables together with some choc-blocks and a couple of din plugs for the controllers. Nobody noticed we had no signals and not much shunting going on! We had the yard with its matrix buttons so were still able to send a selection of trains round in each direction, which is what most of the viewing public want to see anyway.
Indeed, so much to be learned - so little time!That's the beauty of this 'ere forum, you live and learn
Hm Ntm... That is pretty much how I wired things, Diode Matrix and CDU was located by the Fiddle Yard Points but remote panel was 7-10ft away and things just would not fire. I used positive to fire the things as you do, was hoping that you used negative to make the circuit. That might have given full power via the Matrix, might also have saved wear n tear on the Switches. Not a problem for me now as I do not do Shows anymore. But thanks for your lowdown, I still remain confused with my former setup.
JonD
JonD