# wiring council needed



## kormsen (Oct 27, 2009)

i am trying to make a wiring-plan for something that is new to me.
so far i did not come up with a solution, that seems to function.
anybody wants to torture his brain a bit?



what i did before, is run trains in circles, like in the first pic.
one half of the trains is wired in reverse.
the wiring was more or less like this:
(there were variations, but i don't want to sidetrack)












http://kormsen.info/steering/bilder/hafen10.JPG">



well, in reality it was more like this:












http://kormsen.info/steering/bilder/hafen11.JPG">





so far - no problem.


but as a former sailor, living in a half-desert, i simply HAVE TO include a harbour into my layout.
this harbour, as i vision it has two piers with two tracks each. 
the trains drive on one of the piers, then back up on to the other, before they resume their journey around the circle.


so that the whole thing would be like this:












http://kormsen.info/steering/bilder/hafen12.JPG">





how to wire this "double wye" with sidings is what i am braining about. but it seems to be a real brainbuster.


the system is simple analogue DC.
i got more than enough turnout-motors and additional switches (double throw) and reed contacts avayable. (LGB and home-made clones)


this is, what has to happen:


let us pretend, that two trains (one normal, one reversed) are in the northern station.
i already coloured the rails after the polarity needed.









http://kormsen.info/steering/bilder/hafen02.JPG">


the right, outer loop represents the connection with the rest of the layout. for better understanding i leave that out for the moment.


one train leaves north-station, going into the main loop:









http://kormsen.info/steering/bilder/hafen02step1.JPG">


the other train reverses to south-station:









http://kormsen.info/steering/bilder/hafen02step2.JPG">


a train comes from the main loop into south-station:









http://kormsen.info/steering/bilder/hafen02step3.JPG">









http://kormsen.info/steering/bilder/hafen02step4.JPG">


the train, that had backed up into south-station leaves for the main loop:









http://kormsen.info/steering/bilder/hafen02step5.JPG">


the remaining train backs from south-station up into north-station:









http://kormsen.info/steering/bilder/hafen02step6.JPG">


a train from the main loop heads for north-station:
(note - the polarity as shown in the pic has to be changed, before the train enters the station)









http://kormsen.info/steering/bilder/hafen02step7.JPG">


with that, the sequence begins to repeat itself:









http://kormsen.info/steering/bilder/hafen02.JPG">





the goal would be to wire this with less than a hundred wires.
(on the other hand i would not like to let any reed activate more than two motors...)


anybody willing to help my overloaded brain back on track?


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## Greg Elmassian (Jan 3, 2008)

Sorry, indeed sounds like torture! 

But I posted to ask a question, not to give you a hard time.... I'm wondering why you call this a "wye", it does not reverse the orientation (turn) the train. You have passing sidings. Am I missing something? 

At this point, I would have given up and used a computer program. 

I'll bet Todd is up to the challenge though! 

Regards, Greg


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## toddalin (Jan 4, 2008)

Greg is correct, it is not a wye and I had wondered the same thing. But with the current reversals and opposite polarities of the engines, it has some "characteristics" of a wye going on. 

This should be do-able but will require some head scratching in the spare time. 

Lets set some boundaries. I assume LGB turnout motors and EPLs are available and can be run off half-wave or straight dc. Also diodes may be employed as necessary.

Should/would both trains operate simultaneously, or would they alternate their movements? 

Are you open to using relays or should/would you prefer to stay with EPLs, or would some combination suffice? 

Are you open to using track gaps or some combination as opposed to just reed switches? 

Do we assume this as a seperate entity from the main layout?


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## kormsen (Oct 27, 2009)

Greg & Todd, 

if you look at the second and third pic in the original post: 

the first of those two shows, what i started to build. 
imagine each passing siding as a station. six stations numbered one to six. three trains going clockwise and three trains counterclockwise.(three locos have reversed polarity) 
that makes a two-step (automatic) operation. 
step one: 
two trains each leave No. 1,3 and 5 in both directions - two trains each reach stations 2, 4 and 6 from both directions. 
step two: 
all six trains leave the even numbered stations for the neighbouring odd numbered stations. 

that is a simple amplification of the system shown in the very first pic. a non brainer. 

in the third pic (the second of the small ones), there i want to replace two of the passing sidings by two wyes in series.(the third leg of each wye having two sidings) 
hence my denomination of "double wye". 

using a computer program?? - next you'll tell me to use trackplanners too... 
i'm oldfashioned. it's pencil and paper for me. sketch an idea, put it aside. repeat various times, compare sketches. repeat. till it works. 
but this time i got not enough ideas. thats why i try to milk your brains. 

yes, i got more turnout motors, than turnouts - plus some signal motors. 
as i already have been making working copies of epl reed contacts, they and diodes are no limiting factor either. 
i got enough LGB powerpacks with AC output too. 

at the four stations with passing sidings the trains in both directions leave the stations simultaneously, but at the harbor i'll have to stagger departures, because of the bottle necks at the two doubleslips (likely to be replaced by opposing turnouts. the doubleslips i bought, seem to be lost somewhere on the ocean) 

because of the lengths of track involved, i think best would be, if the reversing trains start second and arrive first. 

i tried to get relais, but did not find an inland source for them yet. 
so better to plan without them. 

i tried out the idea with track gaps. 
as DC could fry turnoutmotors, i decided to use them only with the carlock motors i'll use for stub switches. 

no, this is the main layout, we are talking about. at least, what is left of it. 
the she-chief of the local amazones tribe decided to restrict the avayable right of way.


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## toddalin (Jan 4, 2008)

Posted By kormsen on 06 May 2011 03:53 PM 
Greg & Todd, 

in the third pic (the second of the small ones), there i want to replace two of the passing sidings by two wyes in series.(the third leg of each wye having two sidings) 
hence my denomination of "double wye". 




It's not a wye because no train ever turns around, nor can it. They always face the same direction that you put them on the track. What you show are two ends of a point to point railway, with a passing siding in the center, and each end having a siding. If this is not what you had in mind, you need to revise the concept/thinking at this point before moving on.

It could be simpler if the trains only ran consecutively, and not simultaneously. The "two turnouts per toggle" makes things more difficult and the train may have to toggle a couple turnouts then toggle a couple more afterwards but before reaching the destination.


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## kormsen (Oct 27, 2009)

well, is it important, if my habor has two wyes, or two point-ends? for me not. 
important is, that this planned setup is the only way, to realize a harbor in the avayable space, without the trains going backwards for long stretches of track, that i found. 

at the important part - the harbor - the trains will run consecutively. (the only way i can imagine to use the same turnouts). even at the other four stations (the passing sidings) i will soften the simutaneous movement somewhat by different positions for the reeds, that start the trains. 

where is the problem, if a train has to toggle more than one reed switch in a section?


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## Greg Elmassian (Jan 3, 2008)

It was just an innocent question about the wye. You were the person using it, and we asked nicely. 

I'm not trying to tell you to use a computer program either. 

While milking other's brains, you might consider not stabbing back. 

I'm done here. 

Greg


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## toddalin (Jan 4, 2008)

Posted By kormsen on 06 May 2011 08:38 PM 
well, is it important, if my habor has two wyes, or two point-ends? for me not. 
important is, that this planned setup is the only way, to realize a harbor in the avayable space, without the trains going backwards for long stretches of track, that i found. 

at the important part - the harbor - the trains will run consecutively. (the only way i can imagine to use the same turnouts). even at the other four stations (the passing sidings) i will soften the simutaneous movement somewhat by different positions for the reeds, that start the trains. 

where is the problem, if a train has to toggle more than one reed switch in a section? 






OK, just so that we are in agreement that this is not a "wye" per se and trains will not turn around. 

From your discussion I assume that *any train going backwards must take the inner (shorter) path* to avoid problems (makes things more difficult). Also, trains will always face the same ways on the end sidings so that the postion of the engine and reed switches need not change from one end to the other (simplifies things a bit)

There is nothing wrong with going over multiple reed switches, but it may need to get creative. For example, it may happen that a magnet needs to pass over a reed switch to change a turnout (and de-power the siding), then pass over another reed switch to reverse the current. So the two reeds would have to be placed immediately side by side because the train would be coasting to a stop when it triggers the second reed.


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## kormsen (Oct 27, 2009)

yes. the inner path is just six foot long, while the outer bow represents the entire layout of about 300 foot length. 

the use of the track for traffic in both directions has ist own problems. on my last layout i had in some places reeds at a distance of just half a foot one from the other - one countermanding exactly, what the other caused. that way trains in both directions first pass the reed, that gives not suitable commands, then the reed with the needed commands. 
one problem i see for the harbor is, that there are four different trains to start, but not four different turnout direction combinations needed. 
the future harbor area: 










and the rest of the layout (just as far from termination, like the harbor):


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## toddalin (Jan 4, 2008)

OK, I think I've figured it out using one EPL on each turnout and only throwing two turnouts at a time per reed switch with six reed switches. You could do it with four reeds, but you would need to throw four turnouts on two of them. Give me a day to get my thoughts together on the wiring. It is not that difficult and I may be able to "talk" you through it.


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## kormsen (Oct 27, 2009)

really? so quick? 
i went on trying to find a solution myself. now i tried to break up the problem into smaller chunks, when i realiised that the small loop will never see a forwards going train. 
not (yet) including the incoming trains from the outer loop, nor those leaving to the outer loop, i came up with a four-reed "solution" for the trains backing up on the smaller loop. 
(that would be two reeds, if i would allow more load on each - or if i could find and use relais) 
on the pic below, the upper for the southbound backing train, the lower for the northbound backing train. 

but this "solution" is no real solution. it did not survive reality check , measuring on the layout. 
as my trains will be between 7 and 8 foot in length, and this small loop has only 6 foot length, there is no position for the reeds, where they could switch the turnouts, without a train on some of the turnouts... back to square one


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## Ralph Berg (Jun 2, 2009)

Korm,
You're making me dizzy ! 
What did you use to "draw" your layout?

Greg,
I'd hardly refer to what Korm said as "stabbing back". 
When you're a German in Paraguay, I'm sure English is his second or maybe even third language.
Ralph


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## Randy Stone (Jan 2, 2008)

Korm, I don't think wiring is your only problem. Just look at the trains. Everytime they get to a curve, they're jumping the track. Maybe JJ and Stan have been included in the equation?


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## kormsen (Oct 27, 2009)

Ralph, 

well, making the observers dizzy is the main point in all that. nothing more boring, than a train simply going circles and being in sight all the time.
i'm using just good old MSPaint for that. (making one basic plan, then guarding different variations as different pics) 


rivette, 

if they ever should happen to come the 7 or 8 thousand miles south to visit me, i would happily accept some spectacular crashes. (might even invite a neighbour with a videocam) 

if you refer to the trains on the plans - that are the new economic one-centered-bogie-south-american-patent-cars. they adjust to every traffic situation...


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## toddalin (Jan 4, 2008)

Posted By kormsen on 07 May 2011 05:36 AM 
really? so quick? 
i went on trying to find a solution myself. now i tried to break up the problem into smaller chunks, when i realiised that the small loop will never see a forwards going train. 
not (yet) including the incoming trains from the outer loop, nor those leaving to the outer loop, i came up with a four-reed "solution" for the trains backing up on the smaller loop. 
(that would be two reeds, if i would allow more load on each - or if i could find and use relais) 
on the pic below, the upper for the southbound backing train, the lower for the northbound backing train. 

but this "solution" is no real solution. it did not survive reality check , measuring on the layout. 
as my trains will be between 7 and 8 foot in length, and this small loop has only 6 foot length, there is no position for the reeds, where they could switch the turnouts, without a train on some of the turnouts... back to square one 












I will only place reed switches on the four pier sidings, one on the top siding, one on the bottom siding, and two on each of the interior sidings, so train length won't be a problem here. There are no reed switches along the "by-pass" siding. Also the by-pass siding will not be double insulated (or insulated at all) from the four pier sidings, and everything left of the two mainline turnouts will undergo simultaneous polarity changes. In fact, the entire left side need not be insulated from the mainline at all so long as trains remain parked on the mainline (and its sidings) when operations along the by-pass siding occur (but we'll insulate it anyways).

Each of the two "pier turnouts" will use one side of the 030 dpdt to route power to that siding when the turnout is thrown that direction. One of the two by-pass turnouts will be wired with the 030 as a dpdt reversing switch such that when the by-pass is selected the current to the left side of the railroad is reversed (if we leave out the rail gaps, we can also reverse the right side if nothing is happening there as I previously noted).

The heart of the system is in the the EPL on the other by-pass turnout that will be used to route the current from the reed switches so that they are not activated at the wrong times. (This is the part that I need to draw out to get the wiring straight in my head.) Maybe you can see where I'm going from here?


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## kormsen (Oct 27, 2009)

>I will only place reed switches on the four pier sidings, one on the top siding, one on the bottom siding, and two on each of the interior sidings, so train length won't be a problem here. There are no reed switches along the "by-pass" siding.< 

that did not occur to me. 

> Also the by-pass siding will not be double insulated (or insulated at all) from the four pier sidings, and everything left of the two mainline turnouts will undergo simultaneous polarity changes.< 

once you mention it, it sounds logical. 


>In fact, the entire left side need not be insulated from the mainline at all so long as trains remain parked on the mainline (and its sidings) when operations along the by-pass siding occur (but we'll insulate it anyways).< 

yes, because as i see it, there will be trains still moving on the mainline, while a train at the harbor will begin to back up. 

>Each of the two "pier turnouts" will use one side of the 030 dpdt to route power to that siding when the turnout is thrown that direction. One of the two by-pass turnouts will be wired with the 030 as a dpdt reversing switch such that when the by-pass is selected the current to the left side of the railroad is reversed ...< 

yes, understood. 


>The heart of the system is in the the EPL on the other by-pass turnout that will be used to route the current from the reed switches so that they are not activated at the wrong times. ...< 

do i understand that right? you want to interrupt some cables between reed and turnoutmotor at times? 


>Maybe you can see where I'm going from here?< 

i think, i begin to get an idea, what you are up to.


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## toddalin (Jan 4, 2008)

Posted By kormsen on 07 May 2011 02:14 PM 
> do i understand that right? you want to interrupt some cables between reed and turnoutmotor at times? 


>Maybe you can see where I'm going from here?< 

i think, i begin to get an idea, what you are up to. 


Yes, I'm thinking that you may have to.

When the train pulls onto a pier siding it passes over the reed switch and "trips an action." Later, when the train pulls out of that siding, you don't necessarily want that action tripped again, but the engine magnet will still pass over the reed, so you need some way to ignore it. If the trains were to go in a loop, rather than back out, this would not be a concern because you would only pass over that reed one time and trip the appropriate action once.

This is the point where the wiring is giving me a headache and I needed to get away from it and work on the railroad, but I do believe that we can do it.


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## toddalin (Jan 4, 2008)

OK, this is what I’m trying to do. Maybe you can help.

Number the piers from 1 to 4 from north to south (P1, P2, P3, and P4).

Number the turnouts from 1 to 4 going clockwise and starting at the northwestern turnout (T1, T2, T3, and T4). Each turnout has an 030 DPDT. Assume T2 is used as a reverser for the “left side” when it is thrown to the curved position. T3 will be used for reed switch routing. 

The Piers are only “live” when the turnout points to them using 030s (single gapped) mounted on T1 and T4. Double gaps are used east of the siding turnouts.

Here we go.

Train pulls into P1 and trips a reed switch that throws T1 and T4 to the interior pier sidings (P2 and P3).

The train on P2 leaves clockwise to the main line and it, or another, eventually comes to P3.

P3 has two reed switches (your imposed limitation). As train nears the end of P3 the first reed it comes to throws T3 to the curve and T4 to the exterior position (P4). This cuts the power to P3 and throws the EPL that will be used to route the reed switches. The second reed switch throws T1 and T2 and the train sitting on P1 comes to life just as the current is reversed.

The train on P1 backs through the siding to P4. This trips a reed on P4 that throws T1 and T4 to their inner positions. This kills the train on P4 and brings the train sitting on P3 to life and it backs through the siding to P2.

When the train pulls on to P2 it passes two reeds. The first throws T3 to the straight and T1 to the exterior position (P1). This cuts the power to P2 and throws the EPL that will be used to route the reed switches. The second reed switch throws T4 to the straight and T2 re-reversing the current and the train sitting on P4 comes to life and heads back out to the main line.



Not really that complicated once you figure a way to make it ignore the reed switches when necessary.


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## kormsen (Oct 27, 2009)

Todd, 

if i did not missunderstand you, i made a mistake, that i did not include the whole loop in to the plan. 
as you set it up, the harbor, with its two "stations" would set the pace for the whole layout. i don't think, that would work. because there are up to 80 foot of track between the other stations. 
if the shortest distance (the small loop in the harbor) sets the pace, there will be caused havok on the other sections. 

in the seckond pic below i tried to put your descriptions in the plan. 
a possible problems seems to me, that the trains going into P2 or P3 might come to rest exactly above the second reeds, thus frying them with their magnets. 

i changed the plan, including all stations. (P1 and P2 together would be station3. P3 and P4 would be station 4) 
the harbor, with its four piers is replacing two stations with passing sidings. so for the whole picture, P1 and 2 are station 3 and pier P3 and P4 are station 4. 
the whole layout should know only three situations: 
1) two trains (of opposing polarity) in every odd numbered station. 
2) one train on every track-section between stations. 
3) two trains (of opposing polarity) in every even numbered station. 
(the section between stations 5 and 6 is the longest, therefore the trains on this section have to trigger everything else.) 

in the first pic one sees the transition from situation 1) to situation 2). 
(there had been two trains each in station one, in the north harbor (St. 3) and in station five. - the difference between north harbor and the two other stations is, that the train leaving to the mainloop, has to trigger the train backing to south harbor, once itself cleared T2. 

the second pic shows the trains leaving situation three.


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## toddalin (Jan 4, 2008)

OK Korm, I solved the riddle of the Sphynx last night.

The EPL on T3 that was to control the reed switches does not have enough contacts or positions to satisfy all possible scenarios. So, we are going to remove that EPL and just use the turnout as an electric turnout and it will not be routing power.

So, how do we get the reeds to ignore the magnets when necessary, and how can we keep a train from parking over a reed and causing its demise?

We need to add two more turnout motors connected to EPLs and four more reed switches. The reeds will be placed immediately west of the other reed switches (the one on P1 and P4 and the two on P2 and P3). We really want these switches as close together as possible and you should physically glue the two or three reed tubes together, rather than have them in seperate housings. This will ensure that all are tripped and lessen the possiblity of parking over them. (But that will no longer be an issue.)

The new reed switch on P1 and P4 will control an 010/030 and we only need to use one set of contacts of the EPL. The reed switch on P1 routes through one contact of the 030 and the reed switch on P4 routes through the other. The common contact actually allows the current to flow to trigger the turnouts. So when the train arrives at P1, the very last reed it encounters throws the 010/030 to the other side and the reed switch on P1 is cutoff until the train reaches P4 and triggers that reed, that cuts off the P4 reed off and brings the P1 reed back on line so that they always alternate.

We do the same thing for P2 and P3. But in this case, we use both sets of contacts on the 030. One set of contacts will cut off the first reed along the siding and the other set of contacts will cut off the second reed along the siding, turning the control over to the reeds on the complimentary pier as was done on P1 and P4. 

Everything will still play out as I previously noted.

BTW, when the train leaves P1 eastbound around the mainline, it would not be the train that pulls into P4. That would be the last train in the sequence headed in that direction so it should not be that long a wait.


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## toddalin (Jan 4, 2008)

*Another Way to Skin a Cat*

Just to show that there is always more than one way to do things, here is a completely different, cheaper, solution that solves the same problem and accomplishes the same movements. I'm sure that there are other ways this could also be done, but this one was keeping me up (note the time).

Number the piers from 1 to 4 from north to south (P1, P2, P3, and P4).

Number the turnouts from 1 to 4 going clockwise and starting at the northwestern turnout (T1, T2, T3, and T4). Assume T2 has an 030 and is used as a reverser for the “left side” when it is thrown to the curved position. Other than for the turnouts themselves, no other turnout motors or 030s are required.

P1 has a single gap in the northern rail where we want the engine to stop. There is a reed switch located just west of this gap that throws T2 and T3 to the straight (mainline setting). This sets the reverser in the “normal” mode.

P2 also has a gap in the northern rail where you want the engine to stop. But in this case, we will span the gap with a diode, just as if we are setting up a reversing unit’s end of track. There is a jumper wire that goes from this insulated section of track on P2 to the insulated section on P1 beyond its gap.

P2 has two reed switches placed just east of the diode. The westernmost (outer) reed switch throws T1 and T4 to the straight positions for the trains to enter P1 and P4. The easternmost (inner) reed throws T1 and T4 to curved positions for trains to enter P2 and P3.

P3 also has a gap in the northern rail with a diode where you want the engine to stop. But in this case, the diode faces in the other direction. There is a jumper wire that goes from this insulated section of track to the insulated section on P4 beyond its gap.

P3 also has two reed switches placed just east of the diode. The westernmost (outer) reed switch throws T1 and T4 to the straight positions for the trains to enter P1 and P4. The easternmost (inner) reed throws T1 and T4 to curved positions for trains to enter P2 and P3.

P4 has a single gap in the northern rail where we want the engine to stop. There is a reed switch located just west of this gap that throws T2 and T3 to the curved (bypass setting). This sets the reverser in the “reversed” mode.

Lets’ say that initially a train is sitting on P1 behind the gap at the ready

So here we go.

User toggles the turnout and train pulls into P2. As the train passes the first reed switch T1 and T4 are toggled to the inner positions (P2 and P3), then, as the train toggles the second reed it puts the turnouts to the outer (P1 and P4) positions. The engine then passes the diode and stops.

As the engine is passing the diode, its wheels span the gap and power can flow to the isolated section. This also sends power to the train sitting on P1 through the jumper wire. Because this train runs in the opposite direction it takes off eastbound by itself while toggling the reed setting T2 and T3 to the main line (where they already were in this case).

The train (or another) comes around and enters P4, because that’s how the turnouts were left from the train on P2. It crosses the gap and stops, just as it trips the reed. This throws T2 and T3 to the bypass position and reverses the current to the left side.

Now the train that is sitting on P2 comes to life because current can flow through the diode. This train starts to back out and first encounters the western reed throwing the turnout to the outer position (P1 and P4), then to the eastern reed throwing the turnout to the inner (P2 and P3) position and the train backs around the bypass to P3.

On P3 it encounters the eastern reed throwing the turnouts to the inner position (P2 and P3) then the western reed throwing the turnouts to the outer (P1 and P4) positions then crossing the diode and stopping.

As the train is passing the diode, its wheels span the gap and power can flow to the isolated section. This also sends power to the train sitting on P4 through the jumper wire. Because this train runs in the opposite direction it takes off eastbound by itself while toggling the reed setting T2 and T3 to the bypass line (where they already were in this case).

The train pulls into P1 and passes the gap, therefore stopping, while throwing T2 and T3 back to the mainline position and re-reversing (straightening???) the current and everything is ready to start all over again.


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## kormsen (Oct 27, 2009)

you solved the riddle of the spinx. but at me that beast is still smiling maliiciously... 

i tried to bring your descriptions on (virtual) paper. 
the first pic is how i understand your last post....... Edit: last post from may 8! (now i'll try to paint your new description from may 9)
(yellow lines for the feeders to the reeds, orange lines for the output of the reeds. i did not include feeders, that come direct from the powerpack - for clariy/simplicity of the plan) 










this pic is how i understood your former posting. - and, i don't know where i missunderstood you, but it does not make sense to me.


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## kormsen (Oct 27, 2009)

Posted By toddalin on 09 May 2011 03:16 AM 
*Another Way to Skin a Cat*

...

P1 has a single gap in the northern rail where we want the engine to stop. ... 

i am trying to put it on the plan. to have no missunderstanding: on which two of the four piers do the trains face east/right?


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## toddalin (Jan 4, 2008)

Posted By kormsen on 09 May 2011 04:36 PM 
Posted By toddalin on 09 May 2011 03:16 AM 
*Another Way to Skin a Cat*

...

P1 has a single gap in the northern rail where we want the engine to stop. ... 

i am trying to put it on the plan. to have no missunderstanding: on which two of the four piers do the trains face east/right? 

Trains on P1 face eastbound. Trains on P2 face westbound. Trains on P3 face eastbound. Trains on P4 face westbound. Actually, I think _Another Way to Skin a Cat_ is the better way to do it. You only need the four turnout thows (010s), one EPL (030), 6 diodes, and eight rail insulators.

Also, trains always cross the reeds under power. In no case does a train have to coast or slide across a reed after loosing power. This keeps the train from parking over the reeds.

It was very late last night and I left off the last bit of the sequence that should play out.

So here we go.

User toggles the turnout and train pulls into P2. As the train passes the first reed switch T1 and T4 are toggled to the inner positions (P2 and P3), then, as the train toggles the second reed it puts the turnouts to the outer (P1 and P4) positions. The engine then passes the diode and stops.

As the engine is passing the diode, its wheels span the gap and power can flow to the isolated section. This also sends power to the train sitting on P1 through the jumper wire. Because this train runs in the opposite direction it takes off eastbound by itself while toggling the reed setting T2 and T3 to the main line (where they already were in this case).

This train (or another) comes around and enters P4, because that’s how the turnouts were left from the train on P2. It crosses the gap and stops, _*AFTER*_ it trips the reed. (_More on this in a bit._) This throws T2 and T3 to the by-pass position and reverses the current to the left side.

Now the train that is sitting on P2 comes to life because current can flow through the diode. This train starts to back out and first encounters the western reed throwing the turnout to the outer position (P1 and P4), then to the eastern reed throwing the turnout to the inner (P2 and P3) position and the train backs around the bypass to P3.

On P3 it encounters the eastern reed throwing the turnouts to the inner position (P2 and P3) then the western reed throwing the turnouts to the outer (P1 and P4) positions then crossing the diode and stopping.

As the train is passing the diode, its wheels span the gap and power can flow to the isolated section. This also sends power to the train sitting on P4 through the jumper wire. Because this train runs in the opposite direction it takes off eastbound by itself while toggling the reed setting T2 and T3 to the bypass line (where they already were in this case).

The train pulls into P1 and passes the gap, stopping AFTER it trips the reed, while throwing T2 and T3 back to the mainline position and re-reversing (straightening???) the current. 
(This is the part I left out last night.)

When the current is set back to the normal (non-reversed) position, current can now flow thought the diode on P3. The train sitting on P3 leaves going eastbound and and first encounters the the western reed throwing the turnouts to the outer position (P1 and P4), then to the easten reed throwing the turnouts to the inner (P2 and P3) position and the train heads out to the mainline because when the other train backed onto P1 from P4, it reset T2 and T3 to the mainline as it reset the current. This train (or another) then proceeds counterclockwise around the mainline and enters on P2, because thats where they were left when the train left P3.

With respect to the reeds in the isolated sections of P1 and P4. When the train came around the mainline from P1 to P4, the current was flowing in the "normal" direction. The diode on P3 allows curent to flow in that direction and the current makes its way to the isolated section of P4 through the jumper. When the train comes onto P4 and passes the gap, the rail beyond the gap is still alive through the jumper until the train trips the reed and this reverses the current. Once the current is reversed, it can no longer make its way through the diode so the train remains dead on P4 until something spans the diode or re-reverses the current.

The same situation occurs when the train uses the by-pass to go from P4 to P1. When this occurs, the current is in the reversed state. In this state it can pass through the diode on P2, follow the jumper and make its way to the isolated section on P1. This section then stays alive until the engine trips the reed the puts the current back to the normal state and no current will pass through the diode on P2, so the train remains dead until something spans the diode or reverses the current.

Benefits include fewer parts and trains always cross reeds under power (eliminating parking over reeds). Also, there is benefit in having the diode/jumper combination in that when a train comes into P1 or P4, it looses 0.7 volts through the diode, slowing a bit before crossing the reed and stopping. Also, when a train spans a diode to release the other train, for a moment, they share current, slowing the trains a bit during their simulaneous stop/start. 

Another benefit is ease of wiring, The two western reeds always throw T1 and T4 to their outer settings and the two eastern reeds to their inner settings. So the western reeds can simply be wired in parallel as can the two eastern reeds. Furthermore, T1 and T4 always throw together, either inward or outward. So these two turnouts can be wired in parallel. Now you only need one diode for the two western reeds and one diode for the two eastern reeds.

Similarily T2 and T3 always work as a pair either throwing toward the mainline or the by-pass. So they can be wired in parallel. Now we only need one diode from the reed on P1 and one diode from the reed on P4.


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## kormsen (Oct 27, 2009)

i like this one! 
after i put it to the plan, it looks really simple. 

this one will have the honour to be tested first. 

thank you.


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## toddalin (Jan 4, 2008)

Posted By kormsen on 10 May 2011 04:29 AM 
i like this one! 
after i put it to the plan, it looks really simple. 

this one will have the honour to be tested first. 

thank you. 












Yes, I fancy this one too. It's elegant in its simplicity and I bet you could set it up and try it in just an hour if you have everything!

But it has its caveats. For example, the diodes are sensitive to polarity so you need to be careful as to the placement of normal/reversed current engines. Also, if you use lighted cars, you may need to disconnect the first truck from the lighting circuit so that it doesn't cross the gap and let current flow to the engine.

Finally, the engine leaving from P1 and P4 must make it past the gap while the engine on P2 or P3 "stradles" the diode. So, we want to put this reed as close to the gap as possible, but far enough for the longest engine to clear the siding before hitting the reed.

I don't think it really gets any simpler (or cheaper) than this and I would dare anyone to try to do similar movements with anything shy of computer control. (Those R/C and DCC people can eat their hearts out.)

(Don't forget the four diodes that route the turnout current.)


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## kormsen (Oct 27, 2009)

>Yes, I fancy this one too. It's elegant in its simplicity and I bet you could set it up and try it in just an hour if you have everything!< 

you would loose that bet. i'm a real slow worker, and easily distracted. (noit to mention all the "darling dooses") 
at the moment i'm at benchworking the harbor and waiting for new reeds. (i prefer not to use reeds, that already have a couple of years of service fullfilled) 


>But it has its caveats. For example, the diodes are sensitive to polarity so you need to be careful as to the placement of normal/reversed current engines. Also, if you use lighted cars, you may need to disconnect the first truck from the lighting circuit so that it doesn't cross the gap and let current flow to the engine.< 

at the moment i have only two lighted cars, and i always kept their pick up separated from the locos, because in the passing sidings of the last layout i learned that separating is better. 


>Finally, the engine leaving from P1 and P4 must make it past the gap while the engine on P2 or P3 "stradles" the diode. So, we want to put this reed as close to the gap as possible, but far enough for the longest engine to clear the siding before hitting the reed.< 

yep. but after a couple of test runs, i'll know exactly, where tro put them. 


>I don't think it really gets any simpler (or cheaper) than this and I would dare anyone to try to do similar movements with anything shy of computer control. < 

that really would be something, to see something simpler than this. 


>(Don't forget the four diodes that route the turnout current.)< 

no, i wouldn't. just have to test polarities first, before i note them down in the plan.


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## toddalin (Jan 4, 2008)

Posted By kormsen on 10 May 2011 01:29 PM 

>(Don't forget the four diodes that route the turnout current.)< 

no, i wouldn't. just have to test polarities first, before i note them down in the plan. 



I'm like you.

I know where they need to go, but never seem to know their direction except through trial and error. A lot has to do with how the turnout motors are oriented and the position if the internal bar magnet.

The same would apply to the two diodes in the rail gaps on P2 and P3, and I would use trail and error on these, especially if the engines' current has been reversed internally, as half of yours have.

Good luck and let us know how it works out. I would love to see the sequence play out on U-Tube.


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## Nicholas Savatgy (Dec 17, 2008)

Hi Kormy.................







DC is great isn't it.


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