HOmainline NeO6874 *IF* I'm reading the schematic right, AND understanding that you want to use SPDT switches like SPST switches.... (1) take the "north rail" power wire from your mainline DPDT switch, and wire it to one lug (e.g. center) of the SPDT (2) wire one of the other two lugs to the north rail of your yard track. (you'll end up with "up = on" / "center = off" / "down = very off") (3) should be good to go. (EDIT) -- you can also use the third pin to control a second track, so you end up with "up = track1" / "center = neither" / "down = track2") Dan, You did indeed grasp the question correctly. I'll let you know how it works. However, I'd like to continue to use the two SPDTs (one for the north yard, the other for the south yard) that I used on the prior layout. For the other yard, I should then wire the "south rail" power wire from the mainline DPDT to the center lug of its SPDT and one end lug of the SPDT to the gapped (north) rail of its yard track. Correct? Both yards' north rails are gapped.
NeO6874 *IF* I'm reading the schematic right, AND understanding that you want to use SPDT switches like SPST switches.... (1) take the "north rail" power wire from your mainline DPDT switch, and wire it to one lug (e.g. center) of the SPDT (2) wire one of the other two lugs to the north rail of your yard track. (you'll end up with "up = on" / "center = off" / "down = very off") (3) should be good to go. (EDIT) -- you can also use the third pin to control a second track, so you end up with "up = track1" / "center = neither" / "down = track2")
*IF* I'm reading the schematic right, AND understanding that you want to use SPDT switches like SPST switches....
(1) take the "north rail" power wire from your mainline DPDT switch, and wire it to one lug (e.g. center) of the SPDT
(2) wire one of the other two lugs to the north rail of your yard track. (you'll end up with "up = on" / "center = off" / "down = very off")
(3) should be good to go.
(EDIT) -- you can also use the third pin to control a second track, so you end up with "up = track1" / "center = neither" / "down = track2")
You did indeed grasp the question correctly. I'll let you know how it works.
However, I'd like to continue to use the two SPDTs (one for the north yard, the other for the south yard) that I used on the prior layout.
For the other yard, I should then wire the "south rail" power wire from the mainline DPDT to the center lug of its SPDT and one end lug of the SPDT to the gapped (north) rail of its yard track. Correct? Both yards' north rails are gapped.
I understood "North Yard" to be a yard of N tracks, likewise, "South Yard" being somewhere else (not pictured).
Essentially all you've got to do is cut the feeder wire for the "north rail" (i.e. the gapped one) of each yard track somewhere, and install the switch (ideally, you'd use a SPST, as you only need to make or break a single wire).
-Dan
Builder of Bowser steam! Railimages Site
the ungapped "south" rail in the yard is ultimately connected to one of the end terminals of the DPDT reversing switch. The ungapped gaped rail in the yard is connected to the SPDT switch
edit: see correction
the other side of the SPDT should be connected to the other terminal of the DPDT reversing switch that the "north" rails are connected to
did you read Model Railroad Wiring?
the DPDT reversing switch flips the polarity of the rails. in one position north is (+) and south is (-). In the other position, north is (-) and south (+).
the polarity of the center terminals of the DPDT switch are connected to the power supply and do no change polarity when the DPDT is toggled.
greg - Philadelphia & Reading / Reading
Greg,
You wrote: "the SPDT should be wired to same terminal on the DPDT that the gaped "north" rail would have been wired to, not...." The italics are mine.
Would have been wired to or is wired to, or...?
Kerry
HOmainlineI wired it exactly that way some days ago and again just now with one loco in a yard and another on the mainline: the SPDT's center lug (B) is wired to the mainline direction DPDT's +/positive center lug (B); and the SPDT's end lug (A) is connected to the corresponding +/positive north rail in the yard.
the SPDT should be wired to same terminal on the DPDT that the gaped "north" rail would have been wired to, not the center terminal which I assumed is connected to the throttle
otherwise, when the DPDT is in one position, both rails are either positive or negative and tere is no power to the yard.
HOmainlineI'm still thinking the turnouts may somehow be interfering.
I don't think so.
The power going to ungapped rail is a constant. It is never going to change polarity with a SPDT switch. You can only turn the gapped rail power on and off. I don't see how it could have worked differently on your old layout
To change direction you have to use either the mainline DPDT or the power pack reverse switch, or you are going to have to gap both rails and install a DPDT switch to control the yard, one for each. Doing the later means the yard can be a potential reversing section, if you aren't doing your job with the switches.
Henry
COB Potomac & Northern
Shenandoah Valley
Dan,
Done. See my 5:02 pm reply above to Henry and look over the schematic once more please. Is what I want to do possible?
Henry,
I wired it exactly that way some days ago and again just now with one loco in a yard and another on the mainline: the SPDT's center lug (B) is wired to the mainline direction DPDT's +/positive center lug (B); and the SPDT's end lug (A) is connected to the corresponding +/positive north rail in the yard.
However, I get the same result as before: both locos can move simultaneously in the same direction, but toggling the SPDT only moves the yard loco in one direction; otherwise, it's "dead." In order to move it in the other direction, I have to toggle the mainline DPDT. That's the problem.
I want to move the loco within each yard - forward and backward - using only its SPDT, as I did on the former layout. Is that possible and how should it then be wired? Also connect SPDT lug "C" to ??? maybe?
Take another look at turnouts nos. 8 and 10 on the schematic to see which rails are gapped (single and double) and where. The configuration of those turnouts to each other is somewhat different than they were on the former layout (they're now directly connected to each other), when the two SPDTs worked in their respective yards independently of the mainline DPDT.
I'm still thinking the turnouts may somehow be interfering. That's my wild guess anyway.
I don't know why this is so hard, nor how to explain it differently.
You've said you wanted to use both switches.
Wire A to the gapped rail in North Yard. The wire input into B has to be same polarity as the gapped rail. The source of the B wire can be as close as the rail on the mainline side of the gap or it can be elsewhere but not in the reversing section.
When turned to A the yard will be live. Center off or toward B and the yard will be dead. Same for the other yard.
BigDaddy HOmainline For the other yard, I should then wire the "south rail" power wire from the mainline DPDT to the center lug of its SPDT and one end lug of the SPDT to the gapped (north) rail of its yard track. Correct? Both yards' north rails are gapped. Both rails would be getting "south rail" power if you do that. You need to wire it the same as the other switch, only going to the other yard gapped track. A SPDT switch does only 2 or 3 things. It takes power from the center lug B and sends it to A or sends it to C. If it is a center off type SPDT, with the toggle in the middle, it doesn't send any power. It does not change the polarity of the power. A--------B--------C
HOmainline For the other yard, I should then wire the "south rail" power wire from the mainline DPDT to the center lug of its SPDT and one end lug of the SPDT to the gapped (north) rail of its yard track. Correct? Both yards' north rails are gapped.
Both rails would be getting "south rail" power if you do that.
You need to wire it the same as the other switch, only going to the other yard gapped track.
A SPDT switch does only 2 or 3 things. It takes power from the center lug B and sends it to A or sends it to C. If it is a center off type SPDT, with the toggle in the middle, it doesn't send any power. It does not change the polarity of the power.
A--------B--------C
As I suspected. That confirms that I indeed may have incorrectly labeled the wiring schematic for the former layout. On it, both yards' south rails were shown as gapped.
However, if the south (or north) rails of both yards are gapped, is there another way to wire them properly using a dedicated SPDT (center-off) for each yard?
HOmainlineFor the other yard, I should then wire the "south rail" power wire from the mainline DPDT to the center lug of its SPDT and one end lug of the SPDT to the gapped (north) rail of its yard track. Correct? Both yards' north rails are gapped.
No. The reverse loops begin and end where you see the two red lines, indicating that both rails are gapped, drawn across the loop tracks.
In the above diagram, though, the two double-gapped loop rails at the bottom are not visible. Single red lines mean only one rail is gapped.
The yards are part of the reversing loop?
[quote user="rrinker"]
If you have more than one way to get intot he yard area, then EACH needs to have an insulated joiner, otherwise the power will still come in from the main no matter what you do with flipping the SPDT. That's probbaly the only actual issue you are having. Whichever rail gets power from the SPDT int he yard has to be insulated at EVERY connection to the main to keep the power out and only controlled by the SPDT.
--Randy
Randy,
Did you see the PDF schematic posted above by Henry? There is only one way to enter and exit the yards. And in each yard, only one rail (the outside or north) is gapped.
Look over the schematic closely and let me know what you think. Would you like me to send that PDF to you via a personal e-mail. If so, send me a PM.
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Super! And, nope, the cut-off portion is irrelevant. The focus is on turnout nos. 8, 9 and 10 on the right side and the south and north yards near the bottom. Turnout no. 10 is manual.
Note that the hand-drawn green and turquoise lines with the arrows pointing south to the control panel indicate the double reverse loop wiring.
Again, are the inter-connectedness and proximity of those three turnouts to each other at all important in determining just what wiring configuration I need so those two SPDTs do what I want them to do (and as they did on the old layout)?
Thanks, Greg. I'll do that. I've also been reviewing the other Kalmbach wiring books I have. They all show the center lug wired to one track or another, usually in reference to two-cab operation.
My small layout, though, needs and operates on just one power pack. I use a second one to run the Tortioses.
HOmainlineWho's a newbie, Henry?! I'm just gleefully ignorant of too much techy stuff! Wink
Newbie to the ways of this forum, doesn't say anything about your model railroad experience nor even your tech experience. Certain functions on this forum are just weird.
Here it is. The bottom of the pdf is cut off as it was sent to me. Not sure that makes a big difference for the question being asked.
Mel,
Well, I did just that with what I have - "Paint 3D" - but the resulting schematic is distorted into an oblong shape and the critical part with the yards is only partially shown.
I saw no way to manipulate the shape or expand the frame's borders and increasing the percentage of the diagram shown did nothing to change that.
Much more effective, if you'd like to view and comment on the schematic, is to send me a PM with your e-mail, and I'll send it off to you as a PDF.
please read Model Railroad Wiring. i think it will explain why you've been told to connect the gap'd rail to the center terminal of an SPDT switch, possibly anticipating the use of a 2nd throttle.
HOmainline Mel, I have no idea how to do that conversion. I'm on Windows 10, which has an app called "Paint 3D." Same thing or something else?
I have no idea how to do that conversion. I'm on Windows 10, which has an app called "Paint 3D." Same thing or something else?
Who's a newbie, Henry?! I'm just gleefully ignorant of too much techy stuff!
Yep. It's a small (5' x 7') layout, so only a modicum of room for yards. They're adjacent to the freight depot and either - or both - will be used to store a loco plus three or four cars not in use.
Good point. I'm not planning on powering both yards at the same time. I'd just like to have them operate independently - each with a dedicated SPDT - as they did on the old layout. Then again, if just one DPDT can do the job, I'd be satisfied.
On the north side of the layout are what I call a mainline/north siding track and a south siding track, each of which can be powered on or off with its own dedicated SPDT. The actual mainline runs north of both.
If you'd like to see the PDF with the track and wiring schematic, send me a PM with your personal e-mail and I'll send it along.
Thanks! I noticed your message. I'll read it and send you the PDF soon.
Yep. The north (inside) rail of each yard is gapped within each yard. The plastic rail joiner forming the gap is directly connected to the manually-operated turnout no. 10 in the schematic.
See my related reply to Greg elsewhere, where I suggested the possible need for more gaps and/or feeders. Yor thoughts?
I dunno, sounds like talking over it enough times is making it way more difficult than it sounds.
If the power pack connect to a DPDT reversing switch, which connect to the main line, then simply tap off the yard power BEFORE the DPDT switch if you dooon;t want the DPDT to change direction in the yard. But changing the direction on the power pack will change direction on both the yard and the main (unless you also flip the DPDT).
If you want the yards to have independent DIRECTIOON control then you MUST gap both rails going to the yard and wire up another DPDT just like the one for the main line, supplying power from the power pack with the output connections powering the yard. Then you can reverse the direction of a yard train without affecting the mainline train. However, since there's only one power pack - there is absolutely no wy to have real indpendent control What you need are at least two power packs, and several SPDT toggles to connect power pack A or power pack B to a given part of the layout. Basic cab control with common rail wiring, which is what you see in every Atlas plan book.
In the corrected version of your first post, you wrote (italics mine):
"...you could use a single...SPDT switch for both yards. Connect the center lug to the mainline DPDT reversing switch and the end lugs to each yard rail. The switch connects power to one yard or the other, or neither in the center-off position."
Sounds promising - for single-yard only operation. I'll give it a shot.
This is similar to another potential solution I tried when I first took this problem to a knowledgeable modeler (who helped set up my original yard wiring on the old layout in 2016) here in town a few days ago.
He suggested wiring the SPDT's center lug to the gapped yard rail + one end lug to the center lug of the reverse loop's DPDT + the other end lug to the relevant (negative in this case) track power bus. That's when I got loco movement in one direction only (single polarity) within the yard and had to toggle the mainline direction DPDT - and the SPDT - to achieve dual polarity/forwad and backward loco movement.
His suggestion also included connecting the center lugs of the two SPDTs to each other + one end lug of the second SPDT to a gapped rail of one yard + the other end lug to the gapped rail of the other yard. I never got that far.
Stay tuned. And thanks for your suggestions.
BigDaddybut if the power pack stays the same, and Kerry is using the DPDT on the main to control direction, then it does make a difference what powers the SPDT.
i said "power source" to differentiate it from the gap'd rail in the yard. It could be the mainline rail, the appropriate terminal on the mainline DPDT reversing switch or some other connection.
I have plenty of DPDTs, but I simply want to duplicate the wiring using the same two SPDTs (still happily situated on the fascia!) for the yards that I had for the identical yard configuration on an older layout that I tore down in January.
Those two SPDTs are still wired exactly as they were then, when everything worked perfectly (e.g., the yards operated - "live" or "dead" - independently of each other and of the rest of the layout). The only wires I disconnected in the transition were those soldered to the old yard tracks. Somehow, mysteriously, those SPDTs aren't doing the job they did before.
A thought: Since this new layout has two nearby turnouts (DCC-friendly nos. 8 and 9 on the schematic) directly connected to each other - and then no. 8 directly connected to no. 10 (which is manually operated and leads into the yards), I'm thinking that I may need to gap some other rails and/or add feeders in new places.
On the old layout, there was a sectional track or two of separation between turnouts no. 8 and 9. Could this be the difficulty now? If it's relevant, turnout no. 8 leads into one of the reverse loops.
Your thoughts?