So, I have a question from a friend. He wants to know how to wire a wye in DC. He is working in N scale. He can't find anything helpful, and I cant really either. Any help would be greatly appreciated. He has one atlas controller to work with.
I'm beginning to realize that Windows 10 and sound decoders have a lot in common. There are so many things you have to change in order to get them to work the way you want.
color me skeptical. It's just a reversing loop and Atlas controllers have been around a while.
A good book might be an good investment.
https://www.amazon.com/Complete-Atlas-Wiring-Book-Scales/dp/B0006KSLE6
A less expensive book: https://www.ebay.com/itm/EASY-MODEL-RAILROAD-WIRING-1990-PRACTICAL-FLEXIBLE-WIRING-FOR-ANY-LAYOUT/283027440197?hash=item41e5c00245%3Ag%3AIXYAAOSwhHJbCmDl&_nkw=easy+model+railroading&rt=nc
and if you don't want to wait for the post office
http://lmgtfy.com/?q=wiring+DC+Wye
Henry
COB Potomac & Northern
Shenandoah Valley
Atlas Controller shown below with reverse loop (upper diagram). Ignore the Selector modules on the right that control blocks off to the right. And you can ignore Cab B, as it is not required to have 2 cabs (to operate two trains) for a single train with mainline & reverse loop.
The X-Y direction switch (that reverses the loop ploarity) and the Cab A direction switch are used when needed to ensure (1) that the loop polarity matches mainline polarity when & where (depending on turnout poition) a train enters the loop and (2) that the mainline (Cab A) polarity is matched as needed to the loop polarity when the train then exits the loop. I forget exactly how used as I am a DCC guy lately.
http://download.atlasrr.com/pdf/Item220Instructions.pdf
Unfortunately that does not show the wye approach on track isolation & connection specifically but it indicates where an isolated (reversing part) of the wye is connected to the controller X-Y direction switch output. Basically the wye must be separated into a mainline section and an isolated "reversing" section. I noted elsewhere that the isolation can be one rail in some cases but needs to be both rails in others, depending on the turnout type.
There are various wye diagrams around but I did not find everything you need to know in one place using the Atlas Controller. I would suggest using Atlas devices and getting this book which surely explains it all.
https://shop.atlasrr.com/p-8-complete-atlas-wiring-book.aspx
https://www.amazon.com/s/ref=nb_sb_noss_1?url=search-alias%3Daps&field-keywords=atlas+wiring+book
Paul
Modeling HO with a transition era UP bent
BNSF UP and others modelerHe wants to know how to wire a wye in DC.
greg - Philadelphia & Reading / Reading
gregc BNSF UP and others modeler
BNSF UP and others modeler
Since I was snarky in my initial response, I will say, on behalf of the OP, that the above diagram does not help me understand how to use an Atlas controller in this application, which is a black box to me. Yes, I looked at the pdf mentioned above and I don't speak electrical diagrams.
35 yrs ago I used dpdt switches for my reversing loop, not an Atlas controller. If you call what they call the "isolated section" in your pic the mainline and everything past the gaps, the reversing loop it looks like every other diagram of a reversing loop if you ignore there are turnouts instead of a continuous loop.
The "automatic reversers" used in DCC cannot be used in DC. But 2 DPDT switches cost no more than a draft craft beer.
The new Atlas plans are just that, track plans, even though a lot of them come froom the old Atlas books. The OLD Atlas books, by Armstrong and Stepek (yes, THAT Armstrong) used to show all the wiring with Atlas components. Including layouts with reverse loops and wyes.
Of course, thoose books also all showed common rail wiring - which STINKS. But the Atlas components are all designed for common rail wiring. Back in those days, even going back to when I was just a wee lad, we NEVER wired the layouts for common rail. It just isn't how my Dad did it, and I just carried on with my own layouts. I always gapped BOTH rails, and ran two wires fromt he block toggle to the section. Not a common rail in sight. Skip the common rail, wire it like Greg showed, DPDT toggle switches are not expensive.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
BigDaddyI will say, on behalf of the OP, that the above diagram does not help me understand how to use an Atlas controller in this application, which is a black box to me. Yes, I looked at the pdf mentioned above and I don't speak electrical diagrams.
BNSF UP and others modelerHe wants to know how to wire a wye in DC. He is working in N scale. He can't find anything helpful, and I cant really either.
i provided some information. I didn't think the OP was asking about Atlas and I don't know what level of understanding the OP has
i assume the OP is capable of asking, and will ask questions.
In addition to the diagram shown above with the DPDT switch, a wye with at least one dead end can be made fully automatic with a few relays connected to the turnout positions.
You simply need to understand the DC wiring principal of EAST-WEST, and the reversing section can be controlled by the route chosen.
I will post a diagram later when I have access to my desktop.
It can be wired so that a single pushbutton for each of the three routes will throw the necessary turnouts and set the polarity correctly.
The magic of hard wired logic.......
Sheldon
Sheldon, I would like to see you post the diagram you discussed with push buttons and relays to control polarity for a reverse "Y". Could you include the part number or whatever for the relays. I am all D.C. and wanted to do one of these relay systems a few years ago but I just couldn't find the circuit and what relays. Thanks
stevetx Sheldon, I would like to see you post the diagram you discussed with push buttons and relays to control polarity for a reverse "Y". Could you include the part number or whatever for the relays. I am all D.C. and wanted to do one of these relay systems a few years ago but I just couldn't find the circuit and what relays. Thanks
I will be happy to. Just give me a few days to dig it out, get it scaned, etc.
We are getting ready to move, and life is busy.
But I will get it posted for you.
Steve,
OK, here is part of the wiring. The following two diagrams show how to control the turnouts of a wye with only three push buttons that select the route, not the turnouts individually.
The first diagram shows how three relays and three lighted pushbuttons select the routes.
On the second diagram you would only use lower part of the schematic marked as "typical-most turnout comtols", and it would be duplicated for each of the three switch machines controlled by relays A, B, and C.
Later I will publish the diagram of rail gaps and how extra contacts on A, B, and C are used to control track power and polarity.
Sheldon,
Thanks for the awesome diagrams. I will study them and learn. Hopefully, i can build that. Cool that it’s only three push buttons. Looking forward to your gaps for polarity control.
Steve
stevetx Sheldon, Thanks for the awesome diagrams. I will study them and learn. Hopefully, i can build that. Cool that it’s only three push buttons. Looking forward to your gaps for polarity control. Steve
I don't know what your electronics background might be, but it is pretty easy to build this stuff.
A few tips in understanding this stuff.
The diagrams always show the state of relay contacts with the power turned off.
Multiple events will/may happen when the circuit is powered up, or when a button is pushed, you have to remember that electricity moves at near light speed, so think thru the events as if it was slow motion.
Example in the top diagram, with the power off there is no thru route, note the little arrow marks on the small track diagram. As soon as the circuit powers up, turnout relay B is energized and the mainline route is set thru. Everything then moves from there as you select a different route.
More later.
some explanation would be helpful. i'm an EE and some of the symbols are unfamiliar.
it looks like the R1 and R2 inside circles are relay coils and the symbols that look like capacitors with and w/o a diagonal line could be relay contacts, closed and open when relay active?.
i see one contact with an R1 and fours thers with an R2. But it's not clear which contacts are closed with the relay active and in active.
it looks like the R2 relay contacts on the bottom connect the tortoise switch machine, SM, to either 24V or gnd.
it looks like the the buttons and relay contacts energize one relay or the other and the contacts hold them.
there are two pairs of button for the dispatcher and local. one actives R1 and the other button R2.
gregc some explanation would be helpful. i'm an EE and some of the symbols are unfamiliar. it looks like the R1 and R2 inside circles are relay coils and the symbols that look like capacitors with and w/o a diagonal line could be relay contacts, closed and open when relay active?. i see one contact with an R1 and fours thers with an R2. But it's not clear which contacts are closed with the relay active and in active. it looks like the R2 relay contacts on the bottom connect the tortoise switch machine, SM, to either 24V or gnd. it looks like the the buttons and relay contacts energize one relay or the other and the contacts hold them. there are two pairs of button for the dispatcher and local. one actives R1 and the other button R2.
Repectfully, I will be happy to explain. It may be symbols from before your education, but they are standard symbols used in the days of relays. This method of diagram drawing is called a ladder diagram. It makes no atempt to group relay contacts with their coils physically.
A capacitor symbol has one line curved....
That is a normally open contact for the relay coil indicated. A slash thru that symbol is a normally closed contact. Circles with numbers or letters are relay coils unless othewise described.
The state of the circuit is always shown with no power on. There are no solid state components in this circuit except resistors for LED's, shown as a box with an R, just relays, buttons, relay contacts, and the switch machine coils.
Yes, the normally open buttons energize the relays and contacts hold them on until something else turns them off. Relay circuits like this are very common, motor starters on industrial equipment for example.
Hope that helps.
Happy to explain more. I'm not an EE, but I was trained by a very good one and I have been working with and designing relay logic for 45 years. In the 80's I converted lot of these kinds of circuits into software for early PLC's.
https://en.wikipedia.org/wiki/Relay_logic
even though the symbols may be standard, it doesn't mean the logic is obvious. This is my first taste of relay logic, so i'm curious.
i think the first diagram controlling the wye turnouts for each route needs some explanation.
i believe the switches, labeled 1, 2 and 3 control the three wye routes. 1 is A-right/B-left, 2 A-left/C-right and 3 B-right/C-left.
i believe the A, B and C in circles represent a relay that controls multiple turnouts. i'm confused about it's relationship to the turnouts labeled A, B and C.
it would also be helpful explain what happens when when switch is pressed, explaining how multiple relays are affected.
i think the logic is (where capital mean active and lower case inactive or NOT):
A = A & b & cB = a & cC = C & a & b
i believe a button forces a relay to become active. the logic to maintain/hold a relay requires the other two relays to be inactive, so forcing a relay to be active with a button, forces the other relays to become inactive through the contacts holding them.
it's not clear how the A, B and C relays or circuits actually control a turnout (secondary contacts)?
Greg, you pretty much have it. A few details.
Each relay is directly linked to one turnout. The relays used have four sets of form C contacts (4P2T)
One set of contacts is used to drive the switch machine, see the lower portion of the second diagram. That circuit is used for each relay/switch combination to actually drive the switch machine.
Next, on the small track diagram, note the small arrows next to each turnout. That represents the position of the turnouts with their relay de-energized.
So, when the control power is turned on, by default, relay B will energize, that turnout will change position, completing the straight thru route on the wye.
At that point, if you push the button for the A-B route, relay A is energized, relay B drops out, both of those turnouts change position to the A-B route. Relay C is uneffected.
Similarly, if you then push the button for A-C, relay C is energized, relay A drops out, and route A-C lines up, turnout B says in its default branch position.
And, once again pushing the button for the B-C straight thru route, will energize B and return us to the B-C route.
Additional relay contacts will be used to automaticly route DC power only to the selected route, and in the correct polarity.
I will post this diagram in a day or two.
Additional questions welcomed.
Not sure how to explain it better than Sheldon is - despite being a child of an 80's era EE education, my model railroad learning back in the early dyas was based a lot on 50's and early 60's era publications, so the relay logic concept is not so odd to me. What a world we live in today - transistors that are more sensitive AND can carry more power than those used in the original Twin-T detector are available for pennies. The ones used in the Twin-T were several dollars (in 1958 dollars!) each. Ones that could handle the current to run trains or even woorse, the demands of the common twin coil switch motors of the dya, were not easily affordable to the casual hobbyist - that did chnge quickly however. Relay logic was the order of the day - plus no worries about running a relay in some "in between" state instead of fully open or fully saturated. Relays were cheap as surplus, and it was hard to damage one, unlike a relatively fragile germanium transistor.
SO basically what happens is you use the contacts of ooone realy to controlt he coil of another - or a combination of contacts from several relays. By wiring them in different manners you can easily mimic any logic get you want. If the path is in series through the NO contacts of relay A and then through the NO contacts of relay B to get to the coil of relay C - you have an AND gate. A and B have to be energized before C energizes. If either A or B is off, or both are off, C cannot turn on. Parallel the NO contacts of A and B to feed the coil of C, and you have an OR gate. If A or B, or both, are on, C can turn on.
With enough contacts, you can make as complex a logic as you might need - remember before the first vacuum tube coomputers, there were computers built with relay logic. If the design gets too complex, you might be able to simplify the whole thing by applying Boolean algebra - or if yoou had a digital logic course, use a Karnaugh map to generate simplified equivalent logic. Probably wouldn't come to that for model train control, unless you were really trying to get fancy with the control system. If you use DC coil relays, and run out of contacts, you can 'cheat' and throw in some diodes, much like creating a diode matrix turnout control.
Using the split power supply means that only a single SPDT contact is needed to operate the Tortoise - just like wiring a toggle switch and using a split supply. Common to one side of the Tortoise motor, then +12 through one side of the toggle and -12 through the other side of the toggle. Or relay, in this case. You'd need an extra set of SPDT contacts on the relay to use a single rail power supply, to create a reversing switch.
It also helps, I suppose, that I worked in an industrial setting for a while so the method of drawing relay contacts Sheldon uses is not so odd - it was found in the schematics of many of our older machine tools. And if you peruse some of the older hobby magazines you will see similar drawing elements used in relay-based circuits.
Randy,
Relays are still cheap, plenty of room for them under the layout....
And they make neat 1950's clicking noises.....
Split power supplies do all kinds of neat stuff....
I actually looked into using PLC's or other solid state logic - for these circuits, and my signals, relays are cheaper, and as stated before, less layers.
In my signal system, the actual lamp power goes right thru relays on the Dallee detectors, then thru interlocking logic of the turnout relay contacts, then right to the signals and panel lights - no separate logic level and driver level.
Turnouts are all controlled with circuits like the two published here. Occasionally some relays need more contacts and get repeaters.
And the cab selection circuit is eight relays on a custom circuit board, so it is prewired. Just hook up the panel buttons and the cab power buss, and connect two wires to the track block.
There are hundreds of them, but at any given minute, only 20% or less are energized, so power consumption is minimal.
Until the mid 1980's, these kinds of circuits ran every kind of industrial machinery.
I started working in commercial/industrial electrical engineering and construction in 1975..........
We did a job in 1981 where we replaced the controls for one of the most critical sewage pumping stations in the Baltimore system.
About 200 relays controlled three 700 hp, 2,400 volt, variable speed pump motors. I had to convert the ladder diagrams of the relay circuits into program code for Cutler Hammer PLC's. I was 23 years old......
That station is still running on that equipment from what I understand......
rrinker...Of course, those books also all showed common rail wiring - which STINKS....
Randy, I'm curious about your comment on common rail wiring. I use it on my DC powered layout, and it allows me everything I need to run my one-man operations. I didn't use the Atlas controllers, though, as I thought them to take up too much room. Train control is through walk-around throttles.
The layout is point-to-point (several points) and has a wye and two turntables, controlled with dpdt switches, and rotary switches for engine terminal tracks. The wiring was very simple, and has been trouble free.
Wayne
Most of my dislike comes from those Atlas wiring books, which rarely if ever show more than oone single feeder to the common rail fooor the entire layout. That might work on a simple layout, and with very tight rail joiners, but even out 4x8 temporary layout we put up every year had extra feeders - actually, the layout was not common rail at all, all gaps were made with insulated joiners in both rails. This was the way my Dad did it, and he learned electrical wiring in the US Navy, so I figured it was good enough. I just kept doing things the same way when I built layouts myself. Common rail is pretty much right out for DCC, so I haven't had to do anything really different since going with DCC.
Sure it's less wire, but hooking up wires never scared me, even as a kid - I was 5 or 6 when I figured out where my Dad left off on the wiring and completed it and had trains running when he got home from work. Almost everything we had was train set type equipment, even the diesels had split pickup, I don't think ANYTHING we had at the time had all wheel pickup outside of a small 0-4-0 pr a little 4 wheel switcher. It all worked and was easy to understnad = you need 2 wires for a complete circuit and every block had 2 wires, simple and to the point. We used some Atlas components but most of the block toggles were standard toggle switches mounted in a metal strip my Dad made. Another panel with an aluminum plate for toggles and a back plate of plexiglas (so like a triangle with 2 sides) with bolts used as terminals was used to control structure lights and other accessories. Some sections were independent and not connected to the main loops in any way, they just had dedicated power packs. Wish I still had some of the old photos but they have all gotten lost over the years. My Dad built most of it, but I was the only one capable of operating it all without deriling trains.
ATLANTIC CENTRALRelays are still cheap, plenty of room for them under the layout.... And they make neat 1950's clicking noises..... Split power supplies do all kinds of neat stuff.... I actually looked into using PLC's or other solid state logic - for these circuits, and my signals, relays are cheaper, and as stated before, less layers.
reading about old technology is like looking at a classic car from 30 years ago, a steam engine or many GA aircraft still flying after 50 years. All are fascinating. but technology improves, usually more reliable, less complicated but denser in capability and less expensive.
i'm not that familiar with Tortoise switch machines and had to read about them. Unless your controlling them locally with a DPDT switch, it seems difficult to control them remotely without using a relay of some sort.
I think a latching SPDT relay and a dual power supply may be the least expensive solution to controlling Tortoise machine remotely. And one benefit someone explained to me is that the turnouts remain unchanged from the last time the layout was used. (you can detect the turnout position from the tortoise switches).
it seems that single 12V AC supply and diodes to provide +12 and -12V half wave is a less expensive that having either two +12/-12 or +24/+12 supplies.
while even 4PDT relays may not be real expensive, and while relay logic may not be much more complex to figure out and wire than using TTL for applications on model railroad, it just seems simpler and cheaper to implement such logic in software (leodarno). one leonardo can replace a bunch of relays or TTL gates
it's ironic that i agree that the clicking sounds may be an attraction. And doing things in ways that you are confident in and comfortable with is also very important.
i keep thinking of Jay Leno's steam powered car.
Thanks for the additional information, Randy.
rrinker Most of my dislike comes from those Atlas wiring books, which rarely if ever show more than one single feeder to the common rail for the entire layout....
Until quite recently, my layout, about 200' of main line (not counting double track, staging tracks, and industrial sidings) was powered through one wire to the common rail and one wire to the other rail. However, all rail joiners (except those at the bridges, which are removable) are soldered, then gaps were cut where necessary to afford on/off control to some sections of track, usually, but not limited to, passing tracks.When I added the partial upper level, roughly 65' of mainline, and again not counting double track, industrial sidings, and staging tracks, the layout still ran without issue, and that included operations with multiple locomotive on heavy trains and often steep grades. There was never any difference in locomotive performance or a perceptable drop in speed, even when additional locomotives were added.However, after reading of the necessity for additional feeders, even for DC operation, I did relent and added a couple more pairs of wires. As expected, there was no change in locomotive performance, but the wire had been on-hand, so the only expense, a very minor one, was the labour to put it in place.
I will admit that if I had wanted to have multiple operators running their own trains, I'd have likely opted for DCC. However, the layout itself is totally unsuited to such operations, and I'd guess that my layout "design" deliberately reflects my preference for solo operations.
Greg,
Your questions, perspective and replies are always interesting.
I don't know how old you are, but from my life perspective at age 61, thirty year old cars don't really represent the previous technolgy, this does:
That is me, at age 20, in 1977, I had just finished restoring and hot rodding that 1963 Chevy Nova SS. 283 cid, 350 hp, 4 speed, etc. Did nearly all of it myself, just a little help from dad and a friend of his.
And I will admit, I have no desire to go back to those days for a daily driver....
As I have explained, I have programed PLC's, but for me, building solid state circuits, or programing micro processors, is not much fun.
Buying off the shelf solid state solutions are expensive and often not well suited to specific goals.
Reliablity? Well relays served the signal systems on America's railroad until just recently.......and we are not building the Space Shuttle......
Simpler is a matter of perspective, I will grant that. And as you point out, doing what you know is a big part of that perspective.
Tortoise machine? What kind of switch machines do you use? It has been the dominate product for several decades or more?
Back to cost for a minute. Years ago I looked at all sorts of products to control signals and turnouts, I considered DCC, I considered building my own solid state system, I considered computer/software based systems. In the end, you still need all the same inputs and outputs, and that takes wire - and some sort of "driver".
But in the end, DC with the Aristo wireless radio throttles, and the lighted pushbutton relay based controls for cab assignment, turnouts, signaling and CTC was the lowest cost approach as a total package.
I use one slightly expensive off the shelf solid state item, because I am too lazy to build them - Dallee inductive current detectors. But guess what? They come with a relay built in, ready to interface with my system, no logic interface needed, no "drivers" needed.
24 volt ice cube relays, $3 new, $0.50 surplus on ebay, sometimes less. Never had one fail......
Track power diagram coming soon, either I find that file, or draw a new one......yes its a paper file, and a mylar drawing......
Take care,
I may have forgotten to mention, and therefor you may be over looking one very important point.
I developed my fully intergrated Advanced Cab Control system for the Aristo wireless throttles more than a decade ago. I have built several versions of its features, on several layouts for myself and others.
When I was developing it, DCC was more expensive than today, and many of the current processor solutions for signaling and control, and other model railroad specific products did not exist.
But here is one of the big things for me, with most anything in my life, I don't replace things that are not broken and still do what I need them to do.
Despite any skills in technology, I don't just upgrade stuff because something new comes along.
In 1996 I bought a high quality lawn tractor, I still have it, it will likely last the rest of my life.
My house has home automation, for some things, and manual mercury thermostats for the five zones of heat.....
I still listen to my 1700 vinyl records - because they are better than digitally stored music. And I listen to them on REAL speakers with 10" woofers, not some "cubes" and distorted base from some electrically processed sub woofer.
I love the MR archives, as a search engine, then I go pull the hard copy from my MR collection, nearly complete from about 1947 to now.
I still have flip phone, because it has better acoustics for talking - I have a Samsung tablet for all that other stuff......
But I really hate touch screens, never to be found in my train room as a control interface. It is after all September 1954 on my layout.......
But I have a smart TV, fully intergated with my HiFi/Suround sound, BlueRay, Netflix, Amazon.........on my fiber optic cable service.....
Newer is not always better, sometimes it is just different....
I have the relays, the Dallee detectors, the Aristo throttles, they work fine, why would I spend more money?
Indeed, newer is not always better. Relay contacts are essentially immune to any power being applied fromt he wrong end. Try that with a lot of power MOSFETs like you'd need to handle equivalent current, and without designing in protection circuitry, you may end up with a slab of inert silicon. Stationary applications, perhaps you have room for ample protection circuitry, but miniatureized applications like DCC decoders - forget it. Notice how quickly a decoder is fried if power gets applied to the motor drive?
I've always been an advocate to switch machine contacts and/or relay to flip polarity for reversing loops, instead of complex electronics. Why detect and then correct a short when you can avoid one in the first place? That DCC makes it stupidly simple since the phase of the signal on the rails has nothing to do with direction of travel makes it even easier.
Jay Leno's steam cars? I'd LOVE to own one like that. About the only thing they don't have compared to a gosline engine car is quick startup. Otherwise - he's gotten a speeding ticket in one that is over 100 years old. They can easily keep up with modern traffic. They are incredibly simple machines, as well, far less complicated than internal combustion vehicle, even a diesel. That fact they they all run, and he is able to drive them, after over 100 years, says something.
I have plenty of tech on my layout, including lots of microcontrollers. But sometimes, the simple ways are better. My servo switch motor controllers - sure, I could switch frog polarity with solid state switches, but relays are dead simple and are easily driven by the micro using a transistor, resistor, and a diode for BEMF protection. I've had great success using the Digitrax PM42 circuit breaker which uses relays. No problems with sound decoder inrush even in purposely contrived tests. They are about the ONLY DCC circuit breaker than actually breaks BOTH sides of the circuit instead of just one leg like all the electronic ones do.
It appears that my request for Sheldon to post his relay circuit for polarity reverse started a very interesting exchange from Sheldon, Randy, Wayne, and Greg. I have enjoyed reading it and am trying to learn. Heck, I wouldn’t know what relay to even buy. I will say that I can at least relate to Sheldon’s Nova - I traded my ‘50 Chevy for a brand new ‘62 Chevy II. I hold two mechanical engineering degrees. I even had an elective circuits class in college around 1960 - we studied tubes. Never made it to relays much less the “new” solid state stuff. My locomotives are all DC steamers that were kits or RTR in the ‘60s and ‘70s. i have done motor upgrades and lots on CalScale. I’ve soldered simple circuits that are published in our magazines because they say which diode, transistor, resister, capacitor, or bridge to use. So, if the relays in Sheldon’s diagram we’re to have part numbers or whatever, I can build it. I’m dreaming of a passenger operations layout in modules based on the Filmore Avenue Roundhouse (it has a great website) but using a reverse loop for return instead of the rolling units. Again, thanks Sheldon for posting the diagram and all you others for helping to lead this old structural engineer thru the relay maze.
BNSF UP and others modelerHe wants to know how to wire a wye in DC. He is working in N scale.
regarding the original question ... couldn't the toroise switch contacts be used to reverse the polarity of the wyes reverse section automatically depending on the position of the turnout.
as I said earlier, i believe a dual coil (set and clr) latching relay can be used to control each tortoise. three momentary buttons (or pair in parallel) can be connected to the set or clear of the 2 relays for each route. no need for any "explicit" logic
gregc BNSF UP and others modeler He wants to know how to wire a wye in DC. He is working in N scale. regarding the original question ... couldn't the toroise switch contacts be used to reverse the polarity of the wyes reverse section automatically depending on the position of the turnout. as I said earlier, i believe a dual coil (set and clr) latching relay can be used to control each tortoise. three momentary buttons (or pair in parallel) can be connected to the set or clear of the 2 relays for each route. no need for any "explicit" logic
BNSF UP and others modeler He wants to know how to wire a wye in DC. He is working in N scale.
Yes it can. My circuit has other benifits, it will insure the whole route is clear before allowing the train to proceed.
Yes, latching relays will work - they cost more money.
Typically, my system uses one relay or less for each CTC controlled turnout. Single turnouts require two, because normally closed LED lighted push buttons are simply not to be found in the size and type I want for my control panels.
But other groups of turnouts generally require only one per turnout, some require only one for two turnouts - it averages out.
The other thing is this, by using the same core circuits, and same parts, there is economy of inventory and method.
The track diagram and its added benifits beyond simply reversing the polarity are coming.
Again, while it may be more than the OP, or Steve, requested, my circuit is part of and Advanced Cab Control with CTC and signals.
Signals only go green when the whole route is clear.......
The contacts on the Tortise machine are not known for their high current capacity. I use them to power the frogs, but avoid using them as the primary path of the track power. But again, I am running DC, andmany of my trains are pulled by three to four powered units.
The ice cube relays have 5 amp contacts, more than my 4.5 amp regulated power supplies that power each throttle.
On my power distribution boards that feed the blocks, contacts are doubled up to handle 10 amps.
I would not use Tortoise contacts to change the polarity under a powered track. They can CARRY plenty of power to power a frog or whatever, but they aren't rated to SWITCH much power. Plus if you use both sets of contacts to make a DPDT switch, you have no contacts to power the frog or activate signals. What you can do is use one set of Tortoise contacts to power a relay with DPDT contacts. Or glue or some other way attach lever switches so they get activated by the Tortoise arm and use those contacts to switch the track power.