Rotary switch yard turnout control

Model Railroader Layouts and layout building
1

I’m in the brainstorming (daydreaming) phase of planning my switch yard. I don’t have an awful lot of room to devote to a control panel, so the though occurred to me to use a rotary switch. My line of thought is this… I would use a “Snapper” with a diode matrix to control the turnouts, and a rotary switch to select the track I want to switch to, and then press a SPST momentary switch to apply momentary power to throw the turnouts. So I would have the SPST wired to the rotary switch, wired to the Snapper, wired to the diode matrix, wired to the turnouts. Does this sound feasible/impractical/overly complicated?

Any and all feedback is welcomed.

Thanks

Richard

2

A rotary switch will work. You just substitute it for all the individual pushbuttons. Draw out your diode matrix chart in the usual way. Instead of pushbuttons for each route, you use a rotary switch. One side of the C-D supply goes to all the commons of all the twin-coil turnout solenoids. The other side, the “hot” side goes to a pushbutton (use one rated at 3 amps or higher). The other side of the pushbutton goes to the common terminal of the rotary switch. The individual outputs of the rotary switch go to the diode matrix, where the pushbuttons would have been connected. To use, just turn the rotary switch to the track you want and hit the pushbutton.

3

I was browsing through my MR backissues recently and I vividly remember an article which detailed this including diagrams. I’ll see if I can’t find the darn thing again. You might want to search index.mrmag.com as well - I just tried but I didn’t put a lot of effort into it.

The article was from an issue in the last 5 years I believe - maybe as far back as 2000 but definitely no further.

4

this is the way I have built my control panel for the staging yard. I used two rotary switches and one switch for twelve tracks.

Wolfgang

5

I was recently looking at the same thing and came upon this website… (about 2/3rd down the page)

http://home.cogeco.ca/~rpaisley4/StallMatrix.html

Hope it helps

6

…and you answered my next question before I could even ask[bow] Thanks

Has anybody dabbled in building a CDU from scratch? Any good web pages out there (CDU’s for dummies) that might facilitate me (a dummy as far as electronics[D)]) building one? I’ve read that they can be built for under $10 (but less than $30 worth of aggrevation?[%-)])

Thanks

7

Again, a different page of that popular web site has the answer:

http://home.cogeco.ca/~rpaisley4/CircuitIndex.html

(Actually, I gave you the Table of Contents, so you can browse other useful circuits.)

I think my CDU cost me $5, and the most expensive thing was the fancy connectors I put on the board to hook my wires to. The guts of the circuit is 2 resistors and 2 capacitors. Even at Radio $hack prices, they’re still pretty cheap. You will also need some sort of power supply. I used the AC line from an old train transformer, and a cheap diode bridge to rectify the AC and produce the DC that I needed to drive the circuit.

It’s a great “boy’s first electronics project” if you’re just getting back into the hobby after not touching a soldering iron for a decade or two.