# wiring question



## kormsen (Oct 27, 2009)

would th wiring i put in the pic down there work?
if not, why?


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## Bill Swindell (Jan 2, 2008)

It will work as long as you don't connect the 2 tracks together. If you do connect them together, you need to make sure that you don't short anything out as uou go through the crossover.


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## toddalin (Jan 4, 2008)

Assuming that you put an insulator between the two sections on the "hot rail" (not common rail) and the polarities of both power packs are set the same, yes. If the polarities are different, the train will pogo back and forth when it hits the other pack until you stop it or a fuse pops (whichever comes first).

I recognize that you don't want take the easy way out and use "speed reducing diodes" for the downhill runs because you run different polarity engines..., smart.


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## krs (Feb 29, 2008)

I assume the "up" and "down" tracks are simply two different blocks of the same single track section, not separate parallel tracks.

As Bill mentioned, what you need to pay attention to is the situation where the two blocks will be bridged when a metal wheel or lighted car crosses the insulating gaps.


Two things I don't understand - if you really have a regulated power supply like a Meanwell or other switching supply that keeps the voltage constant even when the current draw changes (higher going uphill, lower downhill), then you won't see much of a change in speed of the train going uphill or downhill. The problem with most model railroad power packs is that they are not regulated - a train going uphill draws more current, the voltage of non-regulated model train power pack drops and train slows down; vice versa going downhill.


I also don't understand you comment of using locos with different polarity - why would you want to do that?

And finally - for a situation like yours I would just use one power pack and then take advantage of the change of polarity to run analog trains in opposite directions. So going uphill when the track polarity is one way, apply full voltage and going downhill, when the polarity is opposite, use a few diodes in series or a power Zener to automatically reduce the track voltage to slow the train down.

Knut


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## krs (Feb 29, 2008)

Posted By toddalin on 31 Oct 2010 12:08 PM 

I recognize that you don't want take the easy way out and use "speed reducing diodes" for the downhill runs because you run different polarity engines..., smart.










I don't understand the benefit of running "different polarity" engines.
Could you perhaps elaborate?

Thanks


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## toddalin (Jan 4, 2008)

Posted By krs on 31 Oct 2010 12:32 PM 
Posted By toddalin on 31 Oct 2010 12:08 PM 

I recognize that you don't want take the easy way out and use "speed reducing diodes" for the downhill runs because you run different polarity engines..., smart.










I don't understand the benefit of running "different polarity" engines.
Could you perhaps elaborate?

Thanks 



Lets you run trains in opposite directions around the loop simultaneously, assuming that tuck into a siding and they pull out for each other as he does, or consecutively rather than simultaneously like we do, so they don't crash. It is a real crowd pleaser (How'd you do that???).


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## kormsen (Oct 27, 2009)

first, thanks for your answers. 

Bill, 
the sections are two blocks of the same circle. but not directly one behind the other. 

Todd, 
you got the advantage to know already where i'm headed. 
the diodes i'll use for the station to slow down and speed up the trains in a less abrupt way. 
(btw - does it make a difference, if i put the diodes on the plus or on the minus rail?) 
the two grades are in different directions. one goes down from east to west, the other goes down from west to east. (so to speak) 
some tests today showed, that i need double the force to send a train uphill, than to let it roll downhill. 
so, the idea was, instead of trying electronics that i don't understand to regulate, i thought, that a simple toggling of the powerpack should give me the desired amount of voltage for each situation. 
the rythm of the traffic is in favor to do this. when on one grade a train goes up, on the other grade one goes down. and vice versa. 

Knut, 
most complicated answer last, but not least: 
first, i just learned, that i got a language missunderstanding. 
i did not even know, that things exist, what you described as "regulated power supply". 
i thought, that "regulated" meant to have a dial for voltage and a switch to toggle polarity. (opposed to -for instance- PC powerpacks, where i can regulate nothing) 
so, i have only not regulated power supplies. 
at 6% grade the voltage to move a train up lets a downhill train nearly break the sound barrier! 
no option for me, because i am running wild west choo choos and at the foot of the grades are curves, that are only slightly wider than radius one. 
(so the trains could either break the sound barrier or the wall) 

one or more powerpacks - 
i don't need to change polarity. i want different speeds at different blocks. and i have a dozen small powerpacks. 

different polarity - 
i interchanged on half of my locos the two cables, that connect to the motor. now i got locos, that go to the right, when others go to the left. 
why? - because of the layout chosen. i do not like to "operate" trains. i prefer to let them run in automated mode. but i like the layout to be interesting (not half a dozen trains chasing each other always in the same direction) 

my layout has (gets) two levels. one at tableheight, one at eye-height. 
the two levels are part of the same "circle" of track. (including two 6% grades of about 50' each to connect the levels. 
the folded "circle" has 8 stations. 
each station consists of what in english seems to be called a mainline with a passing siding. at each station the mainline and the passing siding have a "dead" section, where the trains stop. 
the mainline is NOT double tracked. 
let us number the station one to eight. four with odd numbers and four with even numbers. 
on the mainline in each odd numbered station let us put a train headed for clockwise movement. on each siding in the same stations we put the trains with the changed polarity. headed for counterclockwise movement. 
if i start all trains at the same time, each train runs from his odd numbered station to the next even numbered station in its direction. 
next move they all go from even numbered stations to odd numbered stations again. 
that way at any given moment any visitor can see at every part of the layout at least one train. 

the rest is simple to plan, but complicated to arm. 
for each step of the two step rhythm the last "incoming" train has to send the others on their march to the next station. (one of the others must start this last train) 
as contacts i always used reeds, but on this new layout i'm willing to try out Todd's bump A.S.S. system. 
well, the whole affair gets spiced a little by contacts at different points and a couple of "delay-timers" (i ignore the english name) 
plus one or two stations with a second passing siding, that in one direction the incoming train waits two steps, while the previously parked train takes its place. (that way it takes a long time, untill the same two trains meet at the same place) 

i hope, my explanation was clear enough. if not, just ask. 

back to the question of this thread: 
the two grades are at different sections. one is between station 4 (lower level) and station 5 (upper level). the other is between station1 (lower level) and station 8 (upper level) 
due to the two step rhythm, when one has a upgoing train on it, the other has a downgoing train on it. (and the other way around) 
so, if i can toggle the connections of two powerpacks, each grade will have the voltage, that is adequate for that moment. 

so, i hope, i have covered all now. if not, just ask. 

korm


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## toddalin (Jan 4, 2008)

Posted By kormsen on 31 Oct 2010 03:38 PM 
first, thanks for your answers. 

Bill, 
the sections are two blocks of the same circle. but not directly one behind the other. 

Todd, 
you got the advantage to know already where i'm headed.



as contacts i always used reeds, but on this new layout i'm willing to try out Todd's bump A.S.S. system. 

korm 





Makes no difference which rail gets the diodes. You can also use a couple of these instead and they will help save your motors on restart. 

2.5 ohm inrush thermistor

The Bump A.S.S. system is very versatile, but not ideal in all situations, and maybe not this one for you depending on how you do things. For example, I don't use it in the application you have in mind (i.e., passing siding at a station where trains alternate). This is because in a case like this, you only want ONE TRIGGER per movement. With the Bump A.S.S. system, every metal wheel _can and usually will_ trigger the system at normal speeds. Engines and track-lit cars always trigger the system regardless of speed.

So here's what happens.

Assume a train is sitting at the station ready to leave. The other train comes in and triggers the system with the first engine wheel, the train stops, and the other train starts to leave. But the other train was sitting there because its first wheel had triggered the system stopping that train. So now when it starts up, its second wheel is going to hit the gap, and that train will stop with two wheels past the gap. The other train will start to leave, but its second wheels will then trigger the gap, ad infinitum, until all the metal wheels have crossed the gaps. Not an ideal situation.

(BTW, this is also a problem in your methodology for doing the wye unless you put the "C" trigger at the end (like the "B" trigger) so that the caboose/last car triggers it. Otherwise, when you back around, as soon as the caboose hits this gap, it throws the turnout and fouls the rest of the train.)

Sure there are ways around it. For example, when the train hits the gap it could trigger a 555 chip so the rest of the wheels are ignored for say 5 seconds giving the entire train time to clear the siding. But this adds to the complexity and cost when a simple reed will suffice.

With a reed, the train slides past the reed when it stops so does not reactivate it when it restarts until it makes a loop around the circuit.


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## kormsen (Oct 27, 2009)

Todd, 
i NEVER let a train activate itself! 
the problem you see from multiple contacts should be manageable for most situations. 
i am just these days braining about these things, because i have to work in any ASS contacts now for the first station that is getting track - if any are needed there.. 

if, let us say, the trains going up one of the grades trigger (nearly) everything... 
the train going from 4 to 5 triggers - one after the other- every train in an odd numbered station for start (save the station number five) 
the other (opposing) train in station five may not be triggered, before the triggering trian is inside its siding. 
even if that train would pass with 20 metallic wheels over the contact, no damage would be done to the LGB switchmotors or the switches from car-lock systems. (proven fact. they stand multiple commands to the same direction) 
on the same contacts i would hook the shutting off of power in every even numbered station. (so that the trains will stop there) 
one of the trains sent, needs a contact inside the siding it reaches, to activate station five. 

during the other step the train from station 1 to station 8 does the same. (including another train to send station 8 on its way) 

due to the long grades (from station to station nearly 60' - the other sections are only between 15' and 30' long ) there is enough time to allow for enough motionless time in stations plus staggered start-contacts, to make everything look varied and lively. 

but, yes, you are right, for the alternating trains in stations with mainline and two sidings i will have to use reeds. 
the incoming train has to shut down power for its own siding and give power to its paralell - between power source and the contact on the grade! 
but at least this means, that only half of the trains need magnets and there are only four reeds to burn. 

and again, you are right about the wye. my plan can only work, if the only metal wheels are on the loco. 
but wait, till i come up with my ideas to convert the planned simple station 4 into a four legged "wye" (or something similar to it) i really would like to do that. one of the reasons is space. another, i could make some piers and more "water" with ships for "Lost Gulf Harbor". 
a harbor gives lots of opportunities for animations.


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## toddalin (Jan 4, 2008)

Posted By kormsen on 31 Oct 2010 08:37 PM 
Todd, 
i NEVER let a train activate itself! 
the problem you see from multiple contacts should be manageable for most situations. 
i am just these days braining about these things, because i have to work in any ASS contacts now for the first station that is getting track - if any are needed there.. 

if, let us say, the trains going up one of the grades trigger (nearly) everything... 
the train going from 4 to 5 triggers - one after the other- every train in an odd numbered station for start (save the station number five) 
the other (opposing) train in station five may not be triggered, before the triggering trian is inside its siding. 
even if that train would pass with 20 metallic wheels over the contact, no damage would be done to the LGB switchmotors or the switches from car-lock systems. (proven fact. they stand multiple commands to the same direction) 
on the same contacts i would hook the shutting off of power in every even numbered station. (so that the trains will stop there) 
one of the trains sent, needs a contact inside the siding it reaches, to activate station five. 

during the other step the train from station 1 to station 8 does the same. (including another train to send station 8 on its way) 

due to the long grades (from station to station nearly 60' - the other sections are only between 15' and 30' long ) there is enough time to allow for enough motionless time in stations plus staggered start-contacts, to make everything look varied and lively. 

but, yes, you are right, for the alternating trains in stations with mainline and two sidings i will have to use reeds. 
the incoming train has to shut down power for its own siding and give power to its paralell - between power source and the contact on the grade! 
but at least this means, that only half of the trains need magnets and there are only four reeds to burn. 

and again, you are right about the wye. my plan can only work, if the only metal wheels are on the loco. 
but wait, till i come up with my ideas to convert the planned simple station 4 into a four legged "wye" (or something similar to it) i really would like to do that. one of the reasons is space. another, i could make some piers and more "water" with ships for "Lost Gulf Harbor". 
a harbor gives lots of opportunities for animations. 

OK, I understand what's going on. What happens if the train that is supposed to arrive first at a station actually arrives second because it was delayed for whatever reason? Have you provided for this? 

I'm still questioning/pondering you wye as it would seem that once you turn a train, you need to reverse its current without reversing the other 6 or 7 trains and that would keep you from putting it out on the mainline unless it was now running backwards. A little more explanation may help.


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## kormsen (Oct 27, 2009)

i was thinking about implementing a feedback system, so that every train has to anounce when it reaches the station. 
but that would need 16 additional contacts to activate 15 switches one behind the other, before the commanding train can free start the first of the other trains. 
or i have to implement a blocksystem for eight blocks meaning 16 reeds and 8 switches. 

that would not be following the K.I.S.S principle, would it? 

and if i would not double the number of reeds (using always two for the same work-one as back up) i would have to reakon with a crash now and then. 
same as with the planned system... 



the "wye"... the only idea i got, would be more or less like i put here below. 
two stations with two sidings each. the only length to back up for trains in both direction would be between these two stations.

or can you think of something better?


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## toddalin (Jan 4, 2008)

I am still having a “disconnect” with your thinking. Say we’re running 6 trains and trains are sitting at Stations 1, 3, and 5 on the mains and sidings and everything is stopped with the ability to kill any station mainline or siding.

Station 1 mainline (1M) pulls forward and turns the train in the wye and heads back to where he was. The train on the siding at station 5 (5S) does the same thing at the same time using the other wye because they both use similar polarity to approach the wye from opposite ends. Lets say that based on “imaginative triggering” we can sync these two trains go through their wyes, reverse polarity on the mainline, come back to their stations and park and everything is like is was except that these two trains have now been turned. 

Now if we go to move the other two trains at Station 1 and 5, they either have to be backed into the loop (not ideal but workable) or they have to make their way around the circuit. But when they come to Station 3, there are two trains parked in the way so one of these would first have to be moved to Station 2 or 4 to let the train around. Then once they’re parked back at 1M, 1S, 5M and 5S, how do you get 3M and 3S around to the wye. So a train from Station 1 and Station 5 would have to make its way to Station 2 and Station 4 before 3M and 3S could leave.

Not saying it can’t be done, but not so easy to do automatically.

Lets’ deal with 6 stations and one wye between Station 6 and Station 1. Clockwise trains are on the mainline and counterclockwise are on the sidings at Stations 1, 3, and 5.

User initiates the “wye sequence.” Clockwise trains are released simultaneously and move to sidings at Stations 2, 4, and 6 and stop. The train at Station 1 is then released, turns around at the wye, the current is reversed, it returns to where it was, it's turnout is returned to the mainline, and the power is cut. The train at Station 2 does the same in the other direction, and its current is reversed after passing through the wye, followed by Stations 3, 4, 5, and 6, alternating directions as necessary. Once all trains have danced and are back into position, the three trains at Stations 2, 4, and 6 are brought back to join them at Stations 1, 3, and 5 and all train have been turned.


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## kormsen (Oct 27, 2009)

you are even crazier, than i am! 

think simple. the circle was and will function as i described before. no power reverse outside of the "wye". 
as described in the other thread. trains will still go from 4 to 3 and to 5. and in the next step from 3 to 4 and to 2. 
only difference will be, that between 3 and 4 or 4 and 3 they go backwards. 

as you can see on the plan below, the only thing i gain is place for the harbor with unloading animations.


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## toddalin (Jan 4, 2008)

Posted By kormsen on 01 Nov 2010 05:54 PM 
you are even crazier, than i am! 

think simple. they go backwards. 













I would avoid any backwards movement that I could (especially multiple trains simultaneously), except where necessary, and that would be in the wye.

Too many chances for things to go wrong when going backwards, and unless you are using near prototypical curves, you end up with too many derailments. Maybe you'll have better luck than me. My curves are 8 and 10-foot diameter, my turnouts are LGB 1600 and AristoCraft 10-diameter, my couplers are truck-mounted, G-scale Kadees, and I dread pushing trains through the wye or even around the layout.

If implemented using relay logic and reed switches, while the wiring would be more complex, probably using several surplus relays, if you've been buying LGB components, it would be cheaper too. Plus, you would save buying three turnouts and that in itself would way more than offset any costs.


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## kormsen (Oct 27, 2009)

you got a point there. 
specially, as the curve between the two harbor stations would be definitely R1 (as most of my turnouts are) 

but when i have done that part of the benchwork, i will at least set this up as a temporal test track.


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## toddalin (Jan 4, 2008)

Posted By kormsen on 01 Nov 2010 05:54 PM 
you are even crazier, than i am! 




Crazy??? Don’t you mean “crazy like a fox?"

What if we could do what I propose using all off the shelf LGB components, that you probably already are using? I call this _Kormsen’s Pirouette_ and it uses only the LGB 12010/030s attached to the turnouts (that you probably already have), two additional 12010/030s to handle polarity and direction indentification, LGB track insulators, and diodes. No reed switches are used and none of the motive power or rolling stock are required to carry magnets.

For simplicity of explanation, assume a simple flattened oval with your eight stations along the bottom (south side) of the oval, so all trains come/leave in an east or west direction. Lets number the stations from 1 to 8 from the west to the east. Now assume that we put a simple wye along the north side of the oval. We have lead in/out tracks to the east and west, and the “tail track extends to the north.

Each of the eight stations has a “main” and a “siding” and there is a turnout at each end of each station that allows trains to access the sidings from either direction. The sidings have an insulator on the “hot rail” (not the common rail) at each end. About 8” in from each of these insulators is a Bump A.S.S. gap.

Lets use Station 1 as an example for the wiring. We’ll first deal with the turnout on the west end. The center pole on one side of the 030 receives track power. When the turnout is thrown toward the siding, the 030 routes this power to the siding. Similarly, when thrown toward the main, it cuts the power to the siding. (The mains are kept live through this exercise, but it doesn’t mater if they go dead when you throw the turnout to the siding if that helps with the rest of your plan.)

The other side of the 030 is where most of the real work is done. The A.S.S. gap at the _east_ side of the siding is connected to one leg of the 030 (on the west side turnout) such that when the turnout is thrown to the siding, the output of the gap is present at the terminal of the 030. Similarly, The A.S.S gap at the east side of the siding is connected through the 030 at the west end. The a/c that powers the turnouts (a separate pack) is always present on the common rail everywhere on the railroad including the sidings, is used for the gaps. The other end of each station is set up the same way except that it selects the other A.S.S. gap.

So, when the west turnout at Station 1 is thrown to the siding the siding becomes live and the A.S.S. gap at the east side of the siding is active. When a train crosses this gap, the 16 volts a/c present on the rails that makes its way through the A.S.S gap, then makes its way to the 030. From there, through a diode, it 1) will return the Station 1 west turnout to the mainline position, thereby cutting the power to the siding killing the train there, 2) through another diode throw the turnout at the east side of Station 2 toward its siding, and 3) through a third diode energize a 12010/030 set up as a Reverser between the track and power pack.

So, before we get into the actual turning of the trains, lets assume that trains on the mainline first run clockwise (CW) and those on the sidings run counterclockwise (CCW). Also assume that the trains are currently sitting at Stations 2, 4, 6, and 8 (two at each srtation).

The operator pulls the four trains on the mainlines at Stations 2, 4, 6, and 8 onto the sidings at Stations 1, 3, 5, and 7. These trains are all facing CW. The trains remaining at Stations 2, 4, 6, and 8 are all facing CCW.

The operator now throws the turnout at the east side of Station 1. Power routes to the siding and the train proceeds in a CW direction to the wye. The train is turned at the wye (I’ll explain how in a moment) and heads back. The turnout for the siding is still thrown and the train proceeds along the siding until it hits the A.S.S. gap. When it hits the gap, a/c transfers to the 030, then to the three diodes that 1) resets the turnout at the west side of Station 1 back to the mainline, 2) throws the turnout at the east side of Station 2 to the siding to release that train in a CCW direction, and 3) toggles the Reverser so that the train leaving Station 2 heads in the proper direction. This train then goes around CCW, is reversed at the wye and comes back to Station 2 where it 1) toggles its turnout back to the mainline cutting the power to the siding, 2) toggles the turnout at the east side of Station 3, to its siding to release that train, and 3) toggles the reverser so the train leaving Station 3 heads in the proper direction (CW). This is repeated at the eight stations except that the last station does not toggle the turnout Station 1 when the train returns.

This handles what happens at the stations. So now we need to address the actual wye section.

Again, for simplicity of discussion, assume that the wye is along the north side of the oval. The wye uses three turnouts. There are two turnouts along the mainline that lead into the wye, as well as the wye turnout that routes the two legs to the tail track. Lets call these T1 on the west, T2, on the east, and T3 for the tail track. Also for simplicity of discussion, assume that a train is 5-feet long.

There are A.S.S. gaps (G1) at distances of 7 feet west of T1, 7 feet east of T2 (G4), and 7 feet north of T3 (G5). There are also A.S.S. gaps placed 6 feet west of T1 (G2) and 6 feet east of T2 (G3).

G1 and G4 will be used to determine the train’s direction while G2, G3, and G5 will throw turnouts and selectively route power. Through diodes, G2 will always throw T1 and T2 to their straight, mainline positions. G3 will always throw T2 to the curved position and will throw T3 toward T2. The power for the tail track will be controlled using an 030 on its 12010 so it always syncs. G5 will always throw T3 toward T1 and will throw T1 to the curved position toward T3.

In addition to throwing the turnouts, G2 and G3 will be used in conjunction with G1 and G4 to control the polarity. When a train crosses G1 it throws the Directional 12010 such that its 030 selects G3 to send a/c to the Reversing 12010. Similarly, if a train crosses G4, it throws the Directional 12010 such that it selects G2 to send a/c to the reversing 12010/030.

So, here’s the dance, probably unlike any other railroad in the world.

The user brings the trains on the mainline at Stations 2, 4, 6, and 8, into the sidings at Stations 1,3,5, and 7. When the user throws the turnout at the west end of Station 1, the automation starts.

Power is routed to the siding and the train leaves in a CW direction. It comes to G1 and this selects to use the diode pulse from G3. The train continues and crosses G2. This throws T1 and T2 to their straight positions and the train continues along the mainline. The train passes the turnouts and reaches G3. This throws T2 to the curve, T3 to match it, and reverses the current. The train now starts running backwards up the wye to the tail track. The caboose crosses G5 and this throws the T3 to the other direction and T1 to meet the train. When T3 is thrown it also reverses the current to the tail track and the train now heads forward toward T1 and back home to roost. (It also passes G2 that returns the turnouts to their straight position and G1 that selects G3 for power routing, but these do nothing to the train.)

When the train reaches Station 1 it proceeds onto the siding because that’s how the turnout was left. When it reached the A.S.S. gap it shuts off, reverses the current, and starts the train at Station 2 in a CCW direction (as previously discussed).

When this train approachs the wye from the east toward the west, it first encounters G4 and that selects G2 for power routing. The train then encounters G3 that throws T2 turnout to the curve and matches T3 and this train proceeds into the wye, this time engine first. When the train hits the gap G5 in the tail section, it sets T3 toward T1 while reversing the current to the tail, and curves T1 toward T3. The train now backs down toward T1 and out onto the mainline until it hits G2 that reverses the current and resets T1 and T2 to their straight positions and this train now comes home to roost. This will repeat itself until all eight trains have danced and now all trains are back where they started but facing the opposite direction.

To return the trains as they were, we would pull the trains on the mainline onto the sidings in the opposite direction. The train on the main in Station 2 would be on the siding in Station 3 etc until the train from station 8 sits at the siding at Station 1. Then just throw the turnout on the east side of Station 1 to the siding and the trains will do their dance in the opposite direction until they are all where they started.


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## kormsen (Oct 27, 2009)

you are not just plain crazy - you are a crazy genius! 

after the first read i did not understand anything. but at the second read i drew everything on a paper such as you mentioned it. 
that would mean all trains have the same polarity, right? 
if i understood everything right, i could do the same with less trains on two or three stations too? if yes, than this might be the answer to a question i did not put yet.(the future secondary agricultural lines on O track) 

the only reason i found against using the pirouette would be, that there is just one train moving at any given time. 

you bump assed my memory... 
if reversing polarity on the whole line: 
somewhere i got a plan for a two reverse loop line with a couple of passing-siding stations in between. the idea was to change the polarity at every step. 
all trains with the same polarity. on step one all eastbound trains move, on step two all westbound. 
i had planned to make two stops inside each loop. 

after reading your newest idea, i begin to think.... (hurtfull and dangerous...) 
...if i replace one loop with a wye... 

well, i would have to change just those 40 foot of track, which are already nailed down...


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## toddalin (Jan 4, 2008)

Posted By kormsen on 02 Nov 2010 03:34 PM 
you are not just plain crazy - you are a crazy genius! 

after the first read i did not understand anything. but at the second read i drew everything on a paper such as you mentioned it. 
that would mean all trains have the same polarity, right? 
if i understood everything right, i could do the same with less trains on two or three stations too? if yes, than this might be the answer to a question i did not put yet.(the future secondary agricultural lines on O track) 

the only reason i found against using the pirouette would be, that there is just one train moving at any given time. 

you bump assed my memory... 
if reversing polarity on the whole line: 
somewhere i got a plan for a two reverse loop line with a couple of passing-siding stations in between. the idea was to change the polarity at every step. 
all trains with the same polarity. on step one all eastbound trains move, on step two all westbound. 
i had planned to make two stops inside each loop. 

after reading your newest idea, i begin to think.... (hurtfull and dangerous...) 
...if i replace one loop with a wye... 

well, i would have to change just those 40 foot of track, which are already nailed down... 


Well half the trains use the LS/NMRA switch set each way which is why they leave in alternate directions which is as you have them.

You just need an even number of stations, each with a siding and mainline.

Now for the caveats.









When a train comes home to roost, enters its siding, and triggers the Bump A.S.S., it flips the turnout back to the mainline and this disconnects the A.S.S. gap, as it needs to. But as soon as the turnout starts to throw and the gap is disconnected, power to that turnout, the next turnout, and the Reverser is lost. So the duration can be very short and there is the chance that the points may not make it all the way in time. Luckily the 12010s are sort of springy and once they start to travel, they will probably make it all the way..., but maybe not. A little experimentation is in order.

The other concern is unintended interactions through the diode matrix. Unless the diodes are disconnected from the devices they serve, current can often unintentionally find itself where you don't want it. For example, then the train comes to roost at Station 1 and throws the turnout for Station 2, the halfwave pulse could unintentionally find its way down the line to Stations 4, 6, and 8 also throwing those turnouts and releasing those trains. Or, when you throw a turnout from your control panel, through this matrix of diodes, it could throw more turnouts than you intend. I'm not saying it will, but it can happen and this has happened to me in one instance. I would suggest to set up a demo and find if this will be a problem.

The solution to both is not that difficult, but we will add some complexity in that we will add a 555 that will drive a 3pdt relay. When the train now comes into the siding and crosses the gap, it sends the pulse to the 555 chip. This chip holds the 3pdt relay closed for ~1 second. The a/c current from the common rail will pass through the three diodes that lead to the Station 1 turnout, the Station 2 turnout, and the Reverser, then to the three relay armature poles. The normally open end of the three relay poles will go to their respective devices. Unless the relay is activing being fired, there is now no interaction between these devices.


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