JenTown Railroad

An N Scale Model Railroad

Banner Picture

Electrical

The goal was to build a N scale DCC, computer controlled small layout inside of an Ikea cabinet. So far, the cabinet has been built, the track has been laid and tested. It works. That's good but it had to get power from some kind of control system and so far there hasn't been much attention to this aspect. Until now, the electrical parts have just been thrown together and tucked away out of sight. It's a mess and clearly this will not work. It's bad enough already, but there is a lot more electrical equipment to install and it's only going to get worse. Here's a photo of what it looks like at this point.

Yikes! What a mess. Let's clean this up a bit. The wire nuts are for temporary connections. We'll trim those wires up some and use better connectors once we know how the wires will be routed and hence how long they should be.



The Zephyr combination throttle/command station/booster is mounted in a press-fit enclosure underneath the layout. I used thin poster board to shim the inside of the enclosure to create the press-fit. As with all the electrical components, I'm leaving enough slack in the wires to allow me to remove the component from its normal position and place it above the layout so it is easy to access or work on without having to disconnect any wires. The Digitrax PR3 USB connector sits just below the Command Station. Its USB cable routes out of the back of the cabinet to the nearby laptop computer which runs the control software. It's ok to tuck the Command Station out of the way because it will rarley be used as the layout will be software controlled. I leave the Command Station set to a non-existant loco address so it does not cause a real loco to start or stop outside of the control of the software.



There is a backer board with long screws projecting forward. The components are mounted on smaller boards that fit over the screws behind. A wing nut secures the smaller board in place yet is easily removed to allow the small board and its components to be lifted out of the enclosure so they can be worked on. Next time, instead of wing nuts on screws, I might try small hinges at the top of each of the smaller boards which would allow the board to swing up to be worked on.



Looking down from straight above the inside of the cabinet, here we can see one of the BDL 168 Occupancy Detectors lifted out so it can be worked on easily. No wires needed to be disconnected in order to get the BDL 168 into this easy to work on position which is about waist high.



This is the other BDL 168 Occupancy Detector. It looks a lot cleaner because there are no detection sections attached to it yet. I think this one will be cleaner even after it has been hooked up because of the newer style connector blocks. These connector blocks are easier to work with as well. An added bonus: they can be trimmed to size with little effort. The blue BDL 168 connector block does take a bit of time to solder up if you are not used to them. I soldered short wires to each of the terminals on the blue connector. I then used hot glue to secure the blue connector to a small board and trimmed the wires so that they would fit into the screw terminal connectors.

The black terminal block provides the input from Rail A on the Booster. The next terminal block splits out the Rail A input connections to the BDL 168 edge connector and provides the connectors for the 12 volt power positive, negative and ground. Looking at the photo now, it's obvious that all of the Rail A leads could have come from the black connector block which may have been a more intuitive approach. I'm not sure why I did it the way I did here. It must have made sense to me at the time. The last two terminal blocks will connect the Rail A output of the BDL 168 to each of the 16 individual Dectection Sections once they are installed. The actual BDL 168 can be fit into the blue edge connector after everything else has been done.



So far, there are four DS64 Stationary Decoders installed. The Stationary Decoders control the turnout motors hidden beneath the layout. The fourth decoder is not in use yet. The third one has the wires routed properly. I really like this idea of drilling two small holes for each wire and threading the wire through the holes. It makes things neater and will make it more difficult for the wires get pulled from the connector blocks should something catch them. A great idea, I wish I could tell you where I first saw it and give that person proper credit. Alas, I cannot. It is a pretty common trick seen on many web sites. The other wires will be routed in the same fashion as I get time to do it.



This is the inside of the cabinet. Along the far back, hidden by the many black leads from the BDL 168 to the individual detection sections is the Zephyr Command Station and just below it is the PR3 USB connector. To the right of that are some terminal blocks that break out the 12 volt positive, negative and Rail B as needed. Below those terminal blocks is the primary BDL 168. The DS64s continue on the the right. The second BDL 168 is on the left hand end portion of the cabinet. The heavy gauge red and black wires running along the back of the cabinet near the top edge are the main 12 volt power in from the power supply which is not shown in this photo. The power supply is in the right front of the cabinet. That leaves only a part of the right end of the cabinet to house signaling components which have not yet been completed.

Then there is the matter of lighting terminal blocks and I think there will be many of those. Keep in mind that all these components travel up and down inside the cabinet with the linear actuators. We can not put anything in the lower 10 inches of the cabinet or the layout could not be lowered. So this cabinet is just about full and there is still a lot to add. There is still a lot of room on the back side of the board that the layout is built on though.



This is the back side of the layout. In this photo the board is raised up from its normal running position and hinged back to be worked on. This is what it would look like if you were standing next to it.



Recall that this layout is a long oval with no track in the center, only scenery in the center. I haven't built any scenery yet, so as one would expect, the center area has nothing in it. One red Rail B bus runs the length of the layout on either side. Each detection section has its own Rail A feed coming from the BDL 168, those are the black wires. This photo also shows that there are many PL 10 switch machines. Their leads drop independently of the power leads. All of the leads have a good amount of slack to allow the layout to move up and down and allow the layout to be tilted up and back.



I took a common plastic drinking straw cut into smaller lengths to fashion wire looms of a sort. They are attached to the board with hot glue. They are not the prettiest way to hold the wire I'm certain but until I can find something else I like better, they will do.



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