PLC Project for model railroad layout

With the forward-reverse code working, I added the spur track on the other side just like my main layout. Did not do much with it because for the next steps, I will need to re-do this layout and to make it more like my wall layout.

One of the issues I have is my house is not level, so when I built my around the wall layout, there are downgrades and upgrades (to build the wall layout level would have looked weird)  In the videos I posted, you can see the effect as since the whole house is not level, this test layout shows the same thing.

Found a 5 position rotary switch on ebay, and some diodes. Like my wall layout, I am building a compensation box to lower the voltage on the downgrades. Using 4 diodes for each step, this gives a 1.4 volt drop per step. The first position is full voltage. I can have a maximum drop of 5.6 volts.

To build the layout to replicate my wall layout will require some wiring changes to the PLC unit and such. I plan to use the first track power output to power the main line, parts will be full voltage, others reduced. So this will require adding a second relay for track power 1. A diagram of the layout is attached.

Track power 2 will be the throughway next to the side track

Track power 3 will be the side track

Track power 4 will be the spur track.

I also drew out where the optical sensors will be. I have 2 spares, and I may place them between blocks 3 and 4. So when the train backs out of the spur I can detect its forward or reverse motion.

It will be awhile before I post any more progress as some issues came up on the home front and I have not had much time to work on this project. Hopefully soon I will get back to it.

Mike

To get ready for the next phase of the project, I need to add reduced voltage sections as my house is not level. If you watch the videos, you will see the trains run faster on one side verses the other. This is the same affect I have on my wall layout and I built one of these to compensate for it. This is using the diodes back to back to drop the voltage. I used a 5 position rotary switch to cause a 1.4 volt drop for each step. (first position has no drop)

This has worked well for my wall layout so I am building another one for my test layout.

Mike

Next step is to modify my "Manual-Automatic" control section. I got rid of the green board which was used to sense the switch position via "RSC Lights" I don't have enough inputs to use this so it will be replaced with the compensation box. (Reduced voltage) Track power 1 has to be changed to put out both full and reduced voltage via a double pole relay. This also means the first switch has to be changed to a double pole switch. My plan is to use "Track Power 1" as the mainline power. This also gave me a chance to relocate the relays to a better position.  With these changes, Track power 2 and 3 will be reduced voltage (throughway, and side) Track power 4 (spur) will be full voltage. This is the same as my wall layout. 

By eliminating the track switch position sense, it made my terminal block shorter.

The reduced voltage will be fed into the main PLC unit. That unit will also have to be modified for these changes.

Mike

Another plan since I pretty much ripped out this setup, is to make it neater next time. Things got out of hand with the wiring. I had scattered terminal strips all over the place. I plan to make a mount for them and use more multi-conductor cable. The box that has the buttons and such required two cables. I found on Ebay a 15 conductor cable which will do nicely.

Mike

Making changes to the PLC unit, I need to add another relay for track power 1 so I can have both full and reduced voltage. I eliminated the original 10 terminal block and changed it to the snap in type. I also plan to add a 24 volt positive that is always on, (for parts that need to be powered even when the safety relay is tripped) I replaced the plastic and din rail for the terminal block since it needed to be a bit longer. Once done the next step is I needed a slightly longer DIN rail for the relay section so I can add in one more relay.

I lucked out and was able to remove the din rail without having to remove the wiring for the current setup. That saved some time.

Next step is the wiring changes, I plan to run the reduced power through the safety relay and only run one 24 volt through it, the second one was not  needed.

The extra relay will simply be parallel to the first one. 

Mike