This post , my appologies.
Hey Ed) I dont know about you, but not having a radio (or other crew contact), plus seeing a light come up behind me (on same track while standing) would raise the hair on the back of my neck! Prolly go all procul-harem and turn a few shades of grey.
Glad it went well for you on this day, atleast enough to get a good pic.
Ofcourse, we all know of one such event in history.... a rather famous moment it has been made, that didnt quite turn out having two trains in one siding, and another barrelling up from behind supposedly to pass......
The last ride of Casey Jones.
A#1 North!
Douglas
ATLANTIC CENTRALThis is done with simple serial logic starting at the detector or at the "permission" circuit from the dispatcher/cab selectioin relays.
ATLANTIC CENTRALThen it runs thru the detector for that block, and then thru the necessary turnout position interlock contacts, and then to the signal driver.
it's not clear what these statements mean.
what do you mean by "simple serial logic"? what does "starting at" the detector and "runs thru" imply?
sounds like a detector output may pass thru a number of relay contacts and the "signal driver" is something that switches from "green" to "red", actually the lack of a detector signal allows the signal to be "green" and is "red" by default
do your boards support "APPROACH"?
what is the "permissive circuit"? is this a relay path to prevents a the signal driver from displaying "green"
ATLANTIC CENTRALThe diverging route may or may not have detection, but it is interlocked in a similar manner with its own serial logic chain.
don't understand how a signal can be controlled without detection?
is there something that prevents changing a turnout underneath a train because that interlock is occupied?
greg - Philadelphia & Reading / Reading
gregc ATLANTIC CENTRAL This is done with simple serial logic starting at the detector or at the "permission" circuit from the dispatcher/cab selectioin relays. ATLANTIC CENTRAL Then it runs thru the detector for that block, and then thru the necessary turnout position interlock contacts, and then to the signal driver. it's not clear what these statements mean. what do you mean by "simple serial logic"? what does "starting at" the detector and "runs thru" imply? sounds like a detector output may pass thru a number of relay contacts and the "signal driver" is something that switches from "green" to "red", actually the lack of a detector signal allows the signal to be "green" and is "red" by default do your boards support "APPROACH"? what is the "permissive circuit"? is this a relay path to prevents a the signal driver from displaying "green" ATLANTIC CENTRAL The diverging route may or may not have detection, but it is interlocked in a similar manner with its own serial logic chain. don't understand how a signal can be controlled without detection? is there something that prevents changing a turnout underneath a train because that interlock is occupied?
ATLANTIC CENTRAL This is done with simple serial logic starting at the detector or at the "permission" circuit from the dispatcher/cab selectioin relays.
ATLANTIC CENTRAL Then it runs thru the detector for that block, and then thru the necessary turnout position interlock contacts, and then to the signal driver.
ATLANTIC CENTRAL The diverging route may or may not have detection, but it is interlocked in a similar manner with its own serial logic chain.
I should probably not chime in, but here is how I understand this . . .
The process starts with an order from the superintendent or a request from a conductor to the dispatcher to obtain permission for a route to take a train from the main yard to the Acme Industrial Plant.
The train is currently on Track 7 of the main yard. Acme Industrial is on the far side of the layout.
The dispatcher filps a toggle to allow the train to leave the yard on Track 7. Flipping that toggle starts the electronic circuit.
The dispatcher scans the entire layout (in his head, he is the dispatcher after all!) and starts flipping toggles along his intended route, and the current starts passing through dozens of relays along the way, headed for Acme.
If the current can make it entirely through the string (circuit) of relays and wires all the way to the last wire connected to the green LED of the last signal tower unimpeded, the train can get through to the intended destination.
If there are obstruction or blockages along the way (such as occupied blocks, or turnouts lined adversely), the train can begin its journey, but it will have to stop at those blockages (the signal tower aspects will be red) until conditions change (or until the dispatcher moves other traffic out of the way and/or lines turnouts favorably).
At each relay, the output will be "true" or "false" depending on the conditions in the immediate area. To get all the way to the end of the route and pass the last signal under a green LED, every single relay encountered along the way will have to return "true".
Oversimplified, I know. And quite probably a wrong interpretation on my end.
Robert
LINK to SNSR Blog
ATLANTIC CENTRAL Here is a picture of the detectors I use: As you might be able to see, its output is a relay.
Here is a picture of the detectors I use:
As you might be able to see, its output is a relay.
Photos are always helpful.
Who makes this board? Who sells it? How much? Is it currently produced?
Is one board needed for every block?
Are there similar boards for the signal towers?
Similar questions for the "ice cube" relays.
Thanks.
The drawing will make it clear.
A series circuit, where the flow starts at one end and must pass thru each contact in order, in a line.
The decoder has more than one output, and that output can be normally open or normally closed. In fact, $2 more the detector can have six sets of form C contacts.
Yes on the signal circuit the detector output is normally closed sending the signal down the line to the other contacts. Yes, the presence of a train opens that circuit, killing the green signal.
The permission circuit is a logic matrix of other relay contacts that assures that the two selected blocks and the turnout route match. It is not necessary for the simple walk around operation, but it gives the dispatcher eaiser/more complete control.
Actually the "permission" contact can be almost anywhere in the serial chain.
When trackage leaves CTC territory that secondary trackage may or may not be signaled and therefor may not have detection. But the signal at the interlocking will still be there to indicate route and speed as you leave CTC territory.
Remember, CTC is about instructions from the dispatcher, detection is about protection. You can have one without the other.
Approach can be done. I don't use approach on the interlocking signals. My operators don't need to know that the second block ahead of them is occupied at that point in their train movements - BUT, half way through the block there is an approach signal for the next Interlocking.
It displays green if the next block is clear, or yellow if occupied or the route is not aligned and assigned. So for practical purposes it does the same thing as an approach indication would have done back at the interlocking. And it makes the railroad system look bigger than it is, selective compression. It is also much easier to wire.
And it is a better operational situation in our selectively compressed world.
Turnout lockout - yes, I am planning on doing that. Consider that an "optional stand alone accessory". I will detail that at some point. But simply put, once the detection status inside the interlocking is established, it only takes one contact to freeze all the turnout controls in the interlocking.
Understand this is not true down to the last detail prototype signaling. A great many talented modelers .one before me realized that was not practical or senseable for our models. Others will disagree.
But I assure you, if you see it in operation, you will think it is prototypical.
Sheldon
An approach to an interlocking or control point can also indicate some sort of speed restricted route through the limits, such as a diverging route, not just that it is occupied.
Dave H. Painted side goes up. My website : wnbranch.com
ROBERT PETRICK ATLANTIC CENTRAL Here is a picture of the detectors I use: As you might be able to see, its output is a relay. Photos are always helpful. Who makes this board? Who sells it? How much? Is it currently produced? Is one board needed for every block? Are there similar boards for the signal towers? Similar questions for the "ice cube" relays. Thanks.
Ok, this detector was until recently made by Dallee Electronics. They are a small company made these for a long time, and they may be scaling back for retirement, but this item is currently listed out of stock. Maybe they will make more?
There are, or have been, similar products from other companies. The latest price is expensive, $44 each. I bought mine 20 years ago, and bought a lot of them "new old stock" from a local club that never got around to using them before having to take down their layout. But back then about $30 each. I was too lazy to build something....
One detector for each "primary" block. We will get into what a primary block is later. Just understand that all the short sections of track in the interlockings are sub blocks controlled by what is known as "X section control". They have detection but don't need separate detectors, more magic circuits. About 35 detectors for the CTC mainline and passenger terminal on my layout. Hidden staging will use a different method of detection.
Ice cube relays - I bought some new directly from an industrial supplier, also where I bought the cute little LED lighted push buttons, both still available. I only paid about $2.50 per relay back then. I bought ma y more relays off Ebay, industrial surplus, much of it never used, expensive name brand relays, 50 cents each, 30 to 60 at a time.
The relays are a very standard industrial item, even today. Mine are 4 pole, double throw, 24 vdc coils.
Sometimes the bases cost as much as the relays, but I don't like soldering wires right on the relay and then rigging some sort of mounting.
More later, more flooring to install.
dehusman An approach to an interlocking or control point can also indicate some sort of speed restricted route through the limits, such as a diverging route, not just that it is occupied.
Yes, and as described above my speed restricted routes use "yellow" or approach rather than green.
Because this is DC, and my trains and blocks are long, I don't use occupancy "approach" one whole control block behind a red signal. Visually every primary control block is two signal blocks. So that intermediate signal shows the "approach" for the next red, as explained above.
Just a note here, my time period is 1954.
ATLANTIC CENTRAL dehusman An approach to an interlocking or control point can also indicate some sort of speed restricted route through the limits, such as a diverging route, not just that it is occupied. Yes, and as described above my speed restricted routes use "yellow" or approach rather than green. Because this is DC, and my trains and blocks are long, I don't use occupancy "approach" one whole control block behind a red signal. Visually every primary control block is two signal blocks. So that intermediate signal shows the "approach" for the next red, as explained above.
My boiled-down signaling rules are similar.
In general, green means the next two blocks are clear.
Yellow means the next block is clear, BUT the following block is occupied OR the next turnout is lined against traffic (i.e. you're heading into a trailing turnout). In either case, the implication is clear: slow down and proceed with caution because the next signal you encounter might be red.
ATLANTIC CENTRALThe drawing will make it clear.
thanks. anxious to see it
this post brought me a few steps closer, but curious about the details. interested in "what" the circuits (can) do.
would like to see the signal driver circuit.
and curious about "turnout lockout"; i would have thought there's a need to ignore any switches pressed by operators rather than preventing turnouts from being thrown.
dehusmanAn approach to an interlocking or control point can also indicate some sort of speed restricted route through the limits, such as a diverging route, not just that it is occupied.
the club layout has track that is hard to see which isn't indcated by a signal. members are recognizing that APPROACH means the train has exited the block.
here in cumberland, there's a 3 headed signal near the fair grounds. i'm told the top mean proceed, the middle means to stop at a known spot where a crew change can take place. and the bottom indicates a stop signal at Viaduct Junction.
OK, signal logic.
Understand this is just a simple example of a control point turnout leading into a siding. Only the signal approaching the turnout is shown. It has two heads.
This is the signal driver circuit. it is my simple version with no approach signals. This is just one of several ways to do this job.
Additional turnout relay contacts would be in the serial chain for a more complex track arrangement.
You can get deep into relay signal logic by looking up Bruce Chubb's original three color system as detailed in the April 1972 issue of Model Railroader. Do you have archive access?
Remember, this is the circuit driving the switch machine and providing the "turnout relay" contacts. In actual practice, the LED indicators will be wired parallel to the relay coils, not in the switch machine wiring. This was drawn when I was considering some different issues regarding the indicators.
Side note about the turnout control circuit, this circuit controls a "route", so a crossover is a simple route, a single turnout is a simple route. Single turnouts require two relays, but the crossover only requires two relays, the wye only requires three relays. So the average number of turnout control relays per turnout for the whole layout is just above one relay per per turnout.
This is done this way because it makes the LED indicators easier to wire and it provides needed extra contacts.
To answer you question about the lockout, yes that is how it is done. The power ONLY to the hot side of the pushbutton is turned off, so all the turnout relays in the interlocking hold their position and cannot be changed until the pushbutton power is restored. But it can do both, the dispatcher can lock out local control or detection can lock out everyone.
Note the contacts in the upper left of the turnout control circuit.
New topic, the cab selection equipment. Here is that relay board with the relays. This board handles 4 cabs, the boards have connections that allow them to be daisy chained for 8 cabs.
I do consider 8 cabs the maximum that would be practical from a control panel design stand point.
And the typical relay
This is the cab control circuit:
This diagram was lost in posting some how. It is the cab control circuit.
Here's a sketch I use to work out signal logic:
It is schematic and not to scale. This one is to work out the logic specifically for the signal heads at Turnout T14. The CAD file can be easily copied and modified to show the conditions at each and every other turnout. There will be one specifically for each of the 40 or so turnouts on the layout. CAD makes this process easy.
My boiled-down signaling rules are based on conditions two blocks ahead of and beyond the turnout in each direction of travel.
The bold lines in the image show features that directly affect the aspects of the signal heads: the occupancy of the blocks and the alignment of the turnouts.
I can write computer machine code logic statements (usings standard programming terms such as: IF AND OR NOT ELSE) to determine which specific light on which specific signal head is lit and which are dark.
The exercise now is to learn how to do this using hard-wire analog components to establish the unambiguous logic path based on Sheldon's 50+ years' work and knowledge. No easy task.
ATLANTIC CENTRAL
thanks. this simple example ties several pieces together.
but the turnout relay isn't doing more than the DPST contacts on a Tortoise switch machine. i'd really like to see a more complete interlocking node.
could you expand this example to include the signal(s) in the opposite direction, connections to adjacent nodes, as well as how the "turnout lockout" is implemented? (is the eastbound signal indication different for the siding vs the mainline)?
either this example or perhaps the double track junction on the right side of you track plan above the Monocacy River. perhaps you have a drawing for how you intend to wire this node (or some other).
it would be interesting to see some other examples (e.g. vertical interlocking near bottom above road with 12+ turnouts). you must have some notation for describing the logic without using relay symbols
Greg,
This is the "intergration" part.
This only shows one job the turnout relays do.
On the turnout control drawing they are what allows both the tower and dispatcher to control them and have indication of position.
And, I have not yet shown you the track power scheme that directs power thru the interlocking based on route, which is what also provides the ATC buffer zones. This requires contacts on the turnout relays as well.
And, the relays allow creation of circuits like the wye which not only drive the selected route, but return other turnouts to their "normal" position.
So the eight sets of contacts available from the two relays are necessary.
My next installment will be how track power gets thru the interlocking and creates the buffer zone.
I will be saving the "permission" circuit and occupancy interlock for last. Both are somewhat optional features.
Here is what you seem to be missing. Each node does not really connect to the next node on signal level. It does not have to sincevI don't use "real" approach indications or permissive block signals.
The cab selection circuits extend to the tower panel in both directions as I have described several times, but they only go to the panel, they do not need to interact with anything on the next relay board (node),
Some these more detailed drawings and info I will send to you directly.
Robert, is that mainline trackage?
ATLANTIC CENTRAL Robert, is that mainline trackage? Sheldon
It is a generic sketch. It could be a mainline situation, or it could be showing any other turnout on the layout. It is used to determine the situation at any given turnout, and it focuses on that turnout alone. The sketch can be modified for other situations at other turnouts.
Consider some variations:
Not all turnouts have such extensive branches downstream. Such as:
Or:
Or even:
The last one would indicate the last signal tower at the end of a stub track. I do not (yet) have signals that deep into the layout. It is enough of a headache to get the high-visibility stuff.
Notice that the original sketch shows that all turnouts are facing point turnouts from the perspective of an east-bound train. Consider how the aspects of Signal Head S14A would change if Turnout T15 was a trailing point turnout. This scenario would have no effect on Signal Head S14B, Signal Head S14C, and/or Signal Head S14D. Such as:
Sheldon, do you have any photos of your previous layout's dispatcher panel and/or satellite cab control panels? Can they or will they be salvaged and reused on your new layout? Or, is the new layout too different to use any of the old stuff? It seems like the 8 new satellite cab control panels would be pretty much the same as the old ones.
Have you done any work or design on the new dispatcher's panel? Or, is it still way too early for that kind of stuff?
ROBERT PETRICKI can write computer machine code logic statements (usings standard programming terms such as: IF AND OR NOT ELSE) to determine which specific light on which specific signal head is lit and which are dark.
you really only need to write that code once. i believe the I/O pins along with logic parameters can be captured in tables such that modifying the logic or add new signals/turnouts is just a change of a table entry and doesn't require any programming skills
it would be interesing if RRs had a notation for describing the rules implemented within an interlock that would allow the interlock to be implemented with a variety of technologies: mechanical, electrical, relay, software
ROBERT PETRICKThe exercise now is to learn how to do this using hard-wire analog components to establish the unambiguous logic path based on Sheldon's 50+ years' work and knowledge. No easy task.
this isn't a DCC/DC question since DCC, which control locos, it's peripheral to turnout/signal control. the NMRA is supporting the LCC approach. and i would not describe the use of relays contacts as analog
ROBERT PETRICK gregc ATLANTIC CENTRAL This is done with simple serial logic starting at the detector or at the "permission" circuit from the dispatcher/cab selectioin relays. ATLANTIC CENTRAL Then it runs thru the detector for that block, and then thru the necessary turnout position interlock contacts, and then to the signal driver. it's not clear what these statements mean. what do you mean by "simple serial logic"? what does "starting at" the detector and "runs thru" imply? sounds like a detector output may pass thru a number of relay contacts and the "signal driver" is something that switches from "green" to "red", actually the lack of a detector signal allows the signal to be "green" and is "red" by default do your boards support "APPROACH"? what is the "permissive circuit"? is this a relay path to prevents a the signal driver from displaying "green" ATLANTIC CENTRAL The diverging route may or may not have detection, but it is interlocked in a similar manner with its own serial logic chain. don't understand how a signal can be controlled without detection? is there something that prevents changing a turnout underneath a train because that interlock is occupied? I should probably not chime in, but here is how I understand this . . . The process starts with an order from the superintendent or a request from a conductor to the dispatcher to obtain permission for a route to take a train from the main yard to the Acme Industrial Plant. The train is currently on Track 7 of the main yard. Acme Industrial is on the far side of the layout. The dispatcher filps a toggle to allow the train to leave the yard on Track 7. Flipping that toggle starts the electronic circuit. The dispatcher scans the entire layout (in his head, he is the dispatcher after all!) and starts flipping toggles along his intended route, and the current starts passing through dozens of relays along the way, headed for Acme. If the current can make it entirely through the string (circuit) of relays and wires all the way to the last wire connected to the green LED of the last signal tower unimpeded, the train can get through to the intended destination. If there are obstruction or blockages along the way (such as occupied blocks, or turnouts lined adversely), the train can begin its journey, but it will have to stop at those blockages (the signal tower aspects will be red) until conditions change (or until the dispatcher moves other traffic out of the way and/or lines turnouts favorably). At each relay, the output will be "true" or "false" depending on the conditions in the immediate area. To get all the way to the end of the route and pass the last signal under a green LED, every single relay encountered along the way will have to return "true". Oversimplified, I know. And quite probably a wrong interpretation on my end. Robert
Some how I missed this post yesterday.
Robert - no toggles switches - push buttons.
A train in the yard is not in CTC territory, so the yard master or train crew tell the dispatcher they have a departure ready and ask for permission to leave the yard and enter the main.
Turnouts in the yard limit are manually controlled and under the direct control of the train crew with authority from the yard master.
The dispatcher sets the east or west turnout leaving the yard and sets the block they will be entering to their throttle.
They aready have control of the section of the yard they are in - that is a different control protocol.
They proceed out onto the main. The dispatcher may or may not have cleared additional blocks for them at this point.
BUT, overall your understanding of the serial logic that controls permission and the signal aspects is correct.
Robert, regarding your theoretical track arrangements. They can all be done - BUT, I don't have those solutions on the tip of my brain because I don't use traditional "yellow" or "approach" aspects in the block ahead of a red signal.
Most of my blocks are long, 25 to 40 actual feet. My trains are often long as well, 18 to 22 feet is typical.
I want my signals to be functional for the operators, so having control of the block is the info I need to convey. What is going on 35 feet away is not of value to the operator.
So my interlocking signals (absolute signals), never show yellow based on the block ahead being occupied.
Instead I do this:
There is another signal, roughly half way thru the block, that gives warning for the next signal at the next interlocking. It will show yellow if the next signal is red, it will show green if the next signal is green.
You can call it and approach signal, or a "dummy" permissive block signal, making the long control block look like two signal blocks.
True yellow "approach" signals do add a bit more complexity, and they just are not really usefull in running the layout.
Now, yellow signals are used at the interlocking for most diverging routes that would be speed restricted, like entering the yard. Normally that signal head would only have two aspects, red and yellow.
At no point do I use real permissive block signals. No run of track is long enough between interlockings, and again, it is DC so track power assignment is what we are trying to monitor and convey to operators.
To the casual observer the signals look realistic, to the operators they convey the necessary information.
I do not have pictures of the old panels. I do have pictures of panels froma different layout my system was installed on without signaling.
I was just starting the wiring of my last layout when the wife and I decided we where not staying in that house to retire - I stopped building the layout, not just because of that, but about the same time I concluded that I did not like the layout, which was well under way.
It was a very complex double deck affair with way too much hidden track.
And before I had my tablet, I was way lazy at taking pictures.
ROBERT PETRICK Sheldon, do you have any photos of your previous layout's dispatcher panel and/or satellite cab control panels? Can they or will they be salvaged and reused on your new layout? Or, is the new layout too different to use any of the old stuff? It seems like the 8 new satellite cab control panels would be pretty much the same as the old ones. Have you done any work or design on the new dispatcher's panel? Or, is it still way too early for that kind of stuff?
So more specficly, yes I am currently starting to develop the specific circuits for each of the interlocking tower panels on the new layout. I will post a few when they are done "enough" to make sense.
gregc ATLANTIC CENTRAL thanks. this simple example ties several pieces together. but the turnout relay isn't doing more than the DPST contacts on a Tortoise switch machine. i'd really like to see a more complete interlocking node. could you expand this example to include the signal(s) in the opposite direction, connections to adjacent nodes, as well as how the "turnout lockout" is implemented? (is the eastbound signal indication different for the siding vs the mainline)? either this example or perhaps the double track junction on the right side of you track plan above the Monocacy River. perhaps you have a drawing for how you intend to wire this node (or some other). it would be interesting to see some other examples (e.g. vertical interlocking near bottom above road with 12+ turnouts). you must have some notation for describing the logic without using relay symbols
Yes, I will show some more examples.
Yes, as I mentioned to Robert, I have started working on all the interlocking drawings for the new layout.
Yes, the big interlocking is pretty complex.
Because I use lighted pushbuttons in a track diagram for the turnouts/routes, I start with a sketch of what the panel will look like and where the buttons will be. When that makes sense operationally, they I start putting together the logic circuits.
One major point here. The primary goal is to have a straight forward user interface - so it start there, at the panel.
It will likely not make sense for the big interlocking to have too many choices. So it is likely that some diverging and crossover routes may require two or three buttons to be pushed. But it may be sensable to have a master reset that puts all routes back to their mainline default with one button.
More drawings an pictures soon.
Next up how does track power and detection work inside the interlocking limits. Teaser - there are no cab assignment buttons for the trackage inside the interlockings - it is all "automated".
ATLANTIC CENTRALThe primary goal is to have a straight forward user interface - so it start there, at the panel.
not sure what this is implying? seems the only needed inputs at a trackside panel (not CTC) are the turnout (or route) switches and throttle selection switches. are therey others?
ATLANTIC CENTRALIt will likely not make sense for the big interlocking to have too many choices. So it is likely that some diverging and crossover routes may require two or three buttons to be pushed.
i'm curious if within an interlock, individual turnouts need to be selected and only when a valid route exists does a signal become clear?
the other option is (pairs of) buttons selecting a route thru an interlock.
Route selection makes the user interface and implementation of an interlock much simpler
And again, the signal becomes STOP as soon as the route becomes occupied. seems that this may not be implemented with "block" detection
Ok, there are lots of things I can do, and things I choose not to do.
Yss I could choose a more complex route by selecting the two ends. But how is that much different than choosing a route thru a complex interlocking by selecting two, or even three, sub routes? As in the one big interlocking on my layout that you pointed out.
How many buttons do you push to select complex routes with a processor based system? Last time I used a Digitrax throttle it was 5........
The first statement you quoted simply refers to laying out the panel and deciding what buttons are needed or are best.
Ok, I will use an example from the big interlocking. Viewing it from the aisle, the far left rear turnout becomes part of the crossover completed by the slip switch on the next track. That turnout needs no control input for the diverging route. If the upper left leg of the slip switch is selected, that turnout diverges to match it, if that end of the slip is aligned to the parallel track, that turnout is straight thru.
Again, the control buttons for the turnouts are located in a track diagram and light up to "map" the route.
A clear signal requires two things, a complete route, and both blocks on either end assigned to the same throttle. The dispatcher does not have to do any extra operations, but he can lock out the operators from using the local panel.
There are sometimes other special controls on the panels, but yes it is mostly just the turnout/route control buttons and the cab assignment buttons.
As soon as the locomotive enters the interlocking the signal that was clear for him turns red. You will find out how that works soon. The interlocking has detection without having separate detectors, more free magic like the Automatic Tran Stop.
Free magic that makes the inductive detectors worth their high price.
ATLANTIC CENTRAL Free magic that makes the inductive detectors worth their high price.
You mentoned Dallee Electronics earlier in your post showing a photo of these detectors.
I checked out their website, and they are still in business. They have a bunch of stuff for sale, but these particular detectors are listed as 'Out of Stock'. No mention if they'll be replenished, or if the manufacture program for this item is over.
How many do you have (need) for your layout? Just asking to get a rough idea how many a scaled-down version of your layout might need.
ROBERT PETRICK ATLANTIC CENTRAL Free magic that makes the inductive detectors worth their high price. You mentoned Dallee Electronics earlier in your post showing a photo of these detectors. I checked out their website, and they are still in business. They have a bunch of stuff for sale, but these particular detectors are listed as 'Out of Stock'. No mention if they'll be replenished, or if the manufacture program for this item is over. How many do you have (need) for your layout? Just asking to get a rough idea how many a scaled-down version of your layout might need. Robert
I need about 35, I have about 50.
Ok, I will start to explain how track power and detection get thru the interlocking.
Remember left is west, right is east, so the rail away from you is north, the rail close to you is south.
When a route is aligned thru the interlocking, the south rail of the route is connected to west (or left) block. The north rail is connected to the east block.
The train will not have power unless both blocks are connected to the same throttle.
Even if the other blick is powered up by another throttle, because there is no common rail and no common power supply. Each throttle has its own 4.5 amp power supply.
All or part of the other rails in the interlocking will be dead at that point.
Remember the detectors are inductive, all they know is the presence of current flow or not.
Both feeder wires to the block run thru the inductor coil in opposite directions, so the detector will trip when it senses current flow on that block even though the voltage return path is in the other block while in the interlocking.
So both blocks show occupancy while the train is in the interlocking.
ATLANTIC CENTRALI need about 35, I have about 50.
Ah yes... having 150% of what you will ever need.
Now you are singing my song.
-Kevin
Living the dream.
ATLANTIC CENTRALHow many buttons do you push to select complex routes with a processor based system? Last time I used a Digitrax throttle it was 5........
but that's using a DCC system for non-loco control. like your approach, there are much better ways
on the interlocking panel shown right, pairs of buttons on either side of a route select the route. there are internal routes as well (e.g. coach yard). that interlock had 75 routes
ATLANTIC CENTRALThe first statement you quoted simply refers to laying out the panel and deciding what buttons are needed or are best.
this is called human factors. where i worked on phone equipment, there was a group of industrial psychologist that made those assessment, not the engineers
ATLANTIC CENTRALA clear signal requires two things, a complete route, and both blocks on either end assigned to the same throttle.
that doesn't sound typical. sounds like you're using the signal to also make sure the operator can control the train thru the block.
at least i'm interested in understanding your approach, but in the context of using it with DCC.
looking forward to the complete picture