Help with wiring realays to run 2 trains on 1 track w/siding

[lionelsoni]

Here's my take on it:

Assume that the siding is oriented east-west. Create 4 control rails, one outside the switch at each end of the siding, one between the switches at the east end of the eastbound siding, and one between the switches at the west end of the westbound siding. Also isolate the center rail of each siding track.

Wire two relays as follows:

Vacc--R1--E1--K1L1--E2--K1S1(NO)--E8
Vacc--R2--WT1--K2L1--WT2--K2S1(NO)--E8
WT1--K1S2(NC)--E3
WT2--K1S3(NO)--E4
E7---K2S2(NC)--E5
E7---K2S2(NO)--E6

where

Vacc is the fixed accessory voltage, returned to ground

E1 is the east control rail outside the switches
E2 is the west contral rail outside the switches
E3 is the westbound control rail between the switches
E4 is the eastbound control rail between the switches
E5 is the eastbound center rail between the switches
E6 is the westbound center rail between the switches
E7 is the center rail elsewhere
E8 is the (grounded) outside rails elsewhere

R1 and R2 are resistors

WT1 and WT2 are wiring tiepoints
(All points labeled WT1 are connected together; all points labeled WT2 are connected together.)

K1 is a 3-pole relay
K1L1 is the coil of relay K1
K1S1, K1S2, and K1S3 are contacts on relay K1
K2 is a 2-pole relay
K2L1 is the coil of relay K2
K2S1 and K2S2 are contacts on relay K1

Each relay is operated with its coil in series with a resistor and a normally-open contact. This allows the relay to be operated and latched by grounding one end of the coil, or released by grounding the other end. The resistor's resistance must be low enough that the relay will operate with it in series. On the other hand, the resistor must be rated to tolerate the accessory voltage across it indefinitely. Using a lamp rated for the accessory voltage instead of a resistor can greatly reduce the power dissipation, as well as provide a visual indication of the circuit operation.

[Big_Boy_4005]

Dennis, there are a lot of interesting patterns that can be done with this type of automation, 3 train, 4 train, and more.

We had a really cool 5 train pattern at enterTRAINment which used a microprocessor. If I remember correctly it took 24 movements before it repeated.

[dwiemer]

Elliot,
Thanks for the information. Even though I did not ask the question, it has given me some ideas to include in my layout that is now being planned. I am sure I will be asking questions as the plan developes.
Dennis

[Big_Boy_4005]

Todd, I still haven't given you the actual wiring diagram for the original question you asked. Here is a verbal description of what you will need to do with the single siding, if that is still what you have your heart set on.

The switches are a piece of cake, they always are. You can make them sprung, or use ones with a non-derailing feature. I like Lionel's classic O gauge style 072's, but the new fastracks will also work just fine. All that needs to be done, is run 2 control wires between them so that when one throws the other one does the same. This way, the departing train sets it's own return path.

The logic of what the trains are doing is the key to understanding all of this. Detecting the presence of both trains is fairly straight forward, using the insulated rail sections. When both trains are present in their stopping positions on the main and siding, a decision needs to be made about which train should go, that's the tricky part.

The way I do it, is by looking at which train is "missing", not parked in it's stopping position. This means the one that is stopped goes next. The problem is each half cycle of this alternating pattern finds both trains in their stopping positions. In addition to the 2 relays for detecting the trains, there are more 2 relays to determine which track will get power when both trains return.

So here are the logical conditions:
If (A and not B) detected, when (A and B) detected, then power A.
If (B and not A) detected, when (A and B) detected, then power B.

The reason the other diagrams are easier is they use simpler logic, which goes:
B powers A and A powers B, so only when both (A and B) are present, both go.

I'm mildly resisting drawing a diagram of this, until I know what relays you are using, and if you want to continue with the single siding plan. With this explanation, you may have enough info to actually wire it yourself, given your background. Let me know.

[Anonymous]

Thank you all for helping with this project. I used to wired motor control panels with relays and contactors,but wiring from a schematic is alot easier than design, since I was doing this with no formal education.

Todd

[Anonymous]

Big Boy

Many Thanks.
I will give the circuit a try.

Dale Hz

[Big_Boy_4005]

Dale, I didn't design this circuit, but I have built a bunch of them. This image may be a little hard to read, but all of the components are listed on it. The purple lines are connections on the back side of the board. It is just done on perf board, counting the holes. Connections are physically made then soldered.

Click on the photo to enlarge.



The thinking back when I did this was, that it would be easier and more effective to go with common relays, and build these boards and a DC supply. I have done some really cool suff with them over the years. They work great for crossing gates, block signals, and any other accessories that you want to be track activated. This is in addition to the train control. They take a little more work up front, but once you build the units, they become little building blocks.

I use this system on my portable layout. This track plan was used at a show last February, and includes one loop of diagram A (red), intersecting a loop of diagram C (blue). The two diamonds are each protected with 2 of these relay units in an eXclusive OR arrangement.



This is the XOR wiring diagram.

[Anonymous]

Big Boy
I normally use DC coils also. Because I use a latching hold circuit chattering on the described circuit is not a problem. Good AC relays have special wound coils to eliminate chatter. You can also put an RC circuit across the coil which helps.
I am very interested in your delay circuit,would you have a schematic?
Thanks
Dale H

[Big_Boy_4005]

Trevor, you're right, I didn't go into detail describing how to do this. It was something of a test of Berks' level of interest, and I would have to prepare wiring diagrams for his particular situation and material list, which I would be willing to do.

I don't use typical relays. I use 24VDC 3PDT's with a home made delay circuit attached. They are powered by a separate DC supply which has it's ground in common with the outside rail ground. The system is very flexible, and the units are fairly easy to build. The reason for choosing 24VDC coils was that they are rather common and inexpensive, with high current ratings on the contacts.

This is the delay circuit for use with the 24VDC relays.



I call this pile of wires and relays "the brain".



It was originally created to control the train sequence on this track plan.



What Berks wants to do is the same only with 2 trains and not 4. So instead of using 8 relay units, it only takes 4.

Why not AC relays? One thing that I found out early on, which was a great source of frustration, was the wheel contact on the insulated rail tended to be intermittent. This caused the relays to "chatter" and be unreliable. I believe this was why Stan Roy had all of the wheels on his trains nickel plated, as he uses relay control on his layout.

By switching to DC coils, and building these delay circuits, all the problems went away. By using a trim pot in the circuit, the length of the delay could be adjusted. This too is a handy feature.

Now Lionel has their 153IR which may be very useful for this project. It has a couple of advantages. First, it doesn't rely on the insulated rail for train detection, so no chatter problems. Second it has a delay circuit built into the unit.

The drawback to the 153IR is, it only has one set of contacts (SPDT).

This drawback can be overcome by using the 153IR to control a relay with more contacts, at least 2 sets.

I recently talked a forum member through diagram B, using 153IR's, via an email exchange. It was a lengthy process, but highly satisfying when he completed the project successfully.

Like I said earlier, 2 sidings is much easier.

The logic for the turnouts is quite simple for any of the options, and is totally independent of the train control.

[Anonymous]

Big Boy wrote this:
"I haven't seen the book to which Trevor is referring, but Dr Riddle isn't here to answer questions. This is a subject where I have a great deal of experience, and have personally worked with multiple members from the forums to help them build. It is very cool, but few people take the time to try it. "

But then you did not explain how to do it!

He really should get those books by Peter Riddle. They are very well written and easy to follow and they cover this type of issue. It was nice of Dale to write out that whole long explanation of how to do this, but the books cover lots of related topics and step the reader through the various issues. He even provides some resources for finding relays, switches, and other parts.

Anyway, there's a lot of knowledge available from people on this and other forums like Chuckn, Big Boy, and Dale Hz. They are a big help. The books by Peter Riddle are a great reference to have, too.

[Anonymous]

I have WebTV so I cannot draw you a diagram,I am assuming figure A.The problem with automating turnouts is reliabilty and derailments. There are numerous ways to approach the problem ,I will describe 1,all that is required is simple circuitry.. It is more complicated explaining it than doing it. I will assume you can make insulated rails and that you have a dedicated phased power source with a common ground to operate relays and the 2 switch machines on the turnouts This can be an unused tap of a ZW transformer turned up to maximum (20 VAC). The relays coils and center lead to the switch machines will all use this power. The train wheels connecting an isolated outside rail to a powered outside rail will energize a relay coil whenever a car with 2 metal wheels rolls over it. Even with no power to the center rail the relay coils will still energize through the common ground.

For this project I would use 3, 3PDT relays and 2, 1pdt relays having 24VAC coils. 20 volts from a postwar transformer wired as described above will easily activate these coils. You can also use 12 or 24 VDC relays but you would need a bridge rectifier for each one. For a 12 volt system you would have to adjust the ZW handle down to 14 volts.

I will wire and label the relays by function. You will need 4 outside insulated rails. Two can be anywhere on the layout not on the sidings and more than one train lenth from either turnouts. Wire the 2, 1PDT coils to energize on each insulated rail. We will call these relays by their functions,energize and cancel relay.The other 2 insulated outside rails will be inside each of both sidings as long as the maximum stopping distance of the train and towards the end of the sidings to accomodate the train lenth. Wire a 3PDT relay coil to each of these outside insulated rails. Label these relays eastbound and westbound siding relays. Parallel to these insulated outside rails in each siding install a isolated center rail the same lenth. Behind that within the siding install another isolated center rail as long as the maximum train lenth. The last 3PDT relay we will label as "select" relay.

You can now wire all the relays so they perform their functions. The "select " relay coil is wired through the energize and cancel relay contacts so that a train circling in the Eastbound direction will leave it enegized and a train circling in the westbound direction will leave it de energized. One contact in the select relay will be wired through its coil as a hold circuit. It will stay energized until a train energizes the cancel relay. When both trains are in the sidings the select relay will either be energized on its hold circuit or de energized. The second set of its relay contacts can direct the position of the turnouts and the 3rd set of contacts can be used to direct which siding is powered. By using the common blades of the select relay only one siding and one set of turnout coils can be powered at a time.

One set of "Eastbound "and" westbound" siding relay contacts are wired in series so power to the center stop rail is only one when both trains are in the siding. A second set is used so that the turnout machines are only thrown (in the appropriate direction) when both train are in the siding.. Which set is thrown or which block is powered is determined by the position of the select relay contacts which are also in series. Each of the last set of contacts on the eastbound and westbound relays will be used to disconnect the trailing isolated center rail from the transformer power and connect the adjacent 2 blocks together when the train reaches the outside insulated stop rail. This allows the train to be powered from the transformer until it reaches the outside insulated stop rail and keeps pickup rollers from bridging the isolated center rails.

I dont know what kind of switch machines are being used. If they cannot accept continuous power like Atlas switch machines,burnout protection can easily be installed using 2 more relays.. The above system can also be greatly enhanced by installing an interval timer and a soft start circuit so the trains dont jackrabbit out of the sidings. Just depends on how much money and time you desire to put in the project. The cost would be around $50 unless you opt for timers and soft start.That would run about another $100 for material. On the above described circuit you will have to leave both trains on the sidings when you are done with them since the system loses its "memory " when depowered.

Dale Hz

[Big_Boy_4005]

There are a couple of different ways to "skin this cat". I have done it with relays, the way you are trying you do it. It takes 4 relays to do diagram A.

TMCC is the one that needs software. I haven't gotten to that part with my home layout, yet.

Relay logic is an electro mechanical way of making decisions. In order to do the trackplan in diagram A, 2 relays are needed to detect the trains, one on each part of the siding. The other 2 relays keep track of which train is "missing", so when it returns, the other one can go.

[Anonymous]

Hello Big Boy,

So what you are saying is that you are using software that controls PLC's to perform operations, correct.

[Big_Boy_4005]

QUOTE: Originally posted by Buckeye Riveter

Big Boy, when we run the trains in TMCC we often pull them into the siding and wait for the single track to clear. I didn't say it was automatic, but the operators must follow the stop signals.

Very true Buck, and on my home layout that's just part of what will happen. Eventually the computer will be able to do it automaticly also. It can be done just the way Berk wants to do it, but the wiring is a little tricky.

I haven't seen the book to which Trevor is referring, but Dr Riddle isn't here to answer questions. This is a subject where I have a great deal of experience, and have personally worked with multiple members from the forums to help them build. It is very cool, but few people take the time to try it.

When I take my portable layout to shows, it is this kind of thing that really wows the crowds. It's called relay logic, and I'm not sure if there is any train wiring book that has really covered this subject.



These diagrams represent the 3 different 2 train operations. Berks is asking about A, however the relay portion of the operation is easier on B and C.

[Anonymous]

If you really want good, solid advice about wiring your layout to do stuff like this, without resorting to hundreds of dollars for Command Control, you might get one of Peter Riddle, Ph.D.'s books on wiring your Lionel layout (put out by Greenberg's Books). In particular, I'd recommend Wiring Your Lionel Layout, Intermediate Techniques. He also has a more recnt book published by Kalmbach that goes over how to wire your layout. It's good because it is more "modern" but the Greenberg book, Wiring Your Lionel Layout, Intermediate Techniques, really gives excellent wiring diagrams for lots of different applications.

[Buckeye Riveter]

Big Boy, when we run the trains in TMCC we often pull them into the siding and wait for the single track to clear. I didn't say it was automatic, but the operators must follow the stop signals.

[Big_Boy_4005]

TMCC won't help with this situation, nor will the Choo Choo Barn.

I have done this many times, in a wide variety of configurations. The one you are attempting is a slightly tricky one to do with a single siding, because it involves choosing which train should go. I have accomplished this manueuver with the help of 4 relays. 2 relays to detect the trains, and 2 relays to decide which train should go next.

The switches are the easy part, if you are using standard Lionel O gauge or equivilent with a non derailing feature.

There are a couple of easier variations of the 2 train pass, but both involve 2 pair of switches.

[Buckeye Riveter]

Berks, this is exactly why I use TMCC.

That being said, why don't you pay a visit to the Choo-Choo Barn and ask them to show you how to wire the switches. When I started in TMCC, I went to Davis Trains in Cincinnati and asked them how to wire TMCC. They showed me everything and sold me everything. I would assume that the Choo-Choo Barn on a somewhat slow day would do the same for you.

Also, take a look at this web page to see if they have products that may help you.
http://www.three-rail.com/3RHOMET.HTM
I have never used their products, but it seems they would have something that could help you.

Good luck and make sure you tell us how you work it out.

[Anonymous]

Merry Christmas,

Here is what I am wanting to do. I want to run 2 trains on a single track in oppisite directions with a passing siding.
I was planning on spring loaded switched. One train would come into the siding and stop turn on a relay and start the other train. The same thing would happen again when the train running returns to the block.
This all done with Postwar Locos. I just can't seem to get the wiring right for this project.
The Choo-Choo Barn in Strasburg does this on the layout.

Thanks.