gregcif you're using your SPDT switches as simple SPST switches, it shouldn't matter whether the rail or power source is connected to the center lug, as long as one of them is.
I could be lost in the array of DPDT switches, but 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.
Kerry on the right side of this page, click on your messages.
Henry
COB Potomac & Northern
Shenandoah Valley
HOmainlineBut it won't allow both yards to operate simultaneously, independent of the other, which is what worked just fine on the old layout and what I want to duplicate here.
i assume you want to park a locomotive in a yard and use a different loco from the other yard. You would never want, nor need to have both yards powered at the same time.
sounds like eventually you might want a number of tracks to park locomotives on that can be powered off. Understanding the current problem will eventually help with that.
greg - Philadelphia & Reading / Reading
HOmainlineThe wire to the gapped rail must be connected to the center lug of the SPDT rather than to the bus or its feeder.
if you're using your SPDT switches as simple SPST switches, it shouldn't matter whether the rail or power source is connected to the center lug, as long as one of them is.
the diagram below for a SPDT switch illustrates the internal connections of the switch. The "center lug" should refer to 1P in the diagram or the common terminal on the switch. The diagram illustrates that whatever is connected to 1P can be connected to 1T or 2T.
if you connect the power source to 1P, the one yard rail can be connected to 1T and the other yard terminal to 2T. In the center-off positon, 1P should be connected to neither 1T or 2T.
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?
Kerry
Greg,
You wrote in part:
"...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."
This sounds good for getting one yard or the other to be "live." I'll give it a try. But it won't allow both yards to operate simultaneously, independent of the other, which is what worked just fine on the old layout and what I want to duplicate here.
I sent you a pm with my email. I'd be happy to do it.
When you say "the gapped rail", is that inside the yard?
Henry,
Thanks for the info about PDFs on this forum. I have no means of photographing anything, however.
How about if I send the PDF to your personal e-mail via the message feature here? Then you can take a close look at the track configuration and gapped rails, co-joined turnouts (nos. 8, 9 and 10 on the schematic) in the area of the yards etc.
The wire to the gapped rail must be connected to the center lug of the SPDT rather than to the bus or its feeder. My reverse loop DPDTs are so wired, and all my Kalmbach wiring books show it that way as well. I did try your method just to see and got zero current.
re: graphic files -- you also need to post them on some other server, i use imgur.com and provide a URL in the thread post.
in the meantime, i believe this is a link to his Great Northern Wiring Schematic
BigDaddy thought about suggesting a DPDT switch off the power pack, but that would always have the potential for a short if not the same as the mainline.
if my explanation is correct, there's a short when the metal wheels bridge the gap in the yard tracks when the reversing switch is in the position when the yard has no power.
he says he has SPDT switch in quantity. I corrected my comment above about using a single switch to control both yards.
RR_MelConvert the PDF to a JPG and post it normally.
What is normal for us, is not normal for newbies. They can't just control C or paper clip a photo. There are further instructions on a sticky post in the general forum.
gregcou could use a single DPDT switch for both yards.
I thought about suggesting a DPDT switch off the power pack, but that would always have the potential for a short if not the same as the mainline.
DPDT center off switches cost less than a McDonald's latte, not Starbucks, Micky D, on ebay.
you posted this on another forum ... and a .pdf file is not a graphics file (e.g. jpg, gif, png)
HOmainlineI gapped the north rail of each yard track between the end of turnout #10 that leads directly into the yards and the end of the yards. However, when I wired a switch's center lug to a gapped rail and one end lug to the power pack, I got only one-way polarity within the yard. To get two-way polarity within the yard, I also had to toggle the mainline direction DPDT
it sounds like the power pack terminals are connected to the rails thru a DPDT switch wired as a reversing switch. in one position, the DPDT reversing switch connects the positive (+) terminal of the power pack to the "north" rail and in the other position, it connects the (+) terminal to the "south" rail.
by connecting your yard switch directly to the power pack you bypassed the DPDT reversing switch. If you connected the yard switch to the (+) terminal and the "north" rail, there will be no power on the yard tracks when the DPDT reversing switch is in the position that connects the (+) terminal to the "south" rail. In this case, both yard rails are connected to (+).
you can do what BigDaddy suggests or connect the yard switch to the corresponding terminal of the DPDT reversing switch instead of the power pack.
HOmainlineMy objective: to make each yard either "dead" or "alive" and electrically separate from the other - and separate from the mainline DPDT.
you could use a single DPDT 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.
The administrator is going to tell you that it is impossible to attach a pdf file. You can post a picture on someplace like Flickr or Imgur and share the link, but not Google or Facebook.
Don't you need the polarity of the yard to be the same as the mainline, to prevent a potential short?
I would think the center lug should get its power from the the North rail feeder or bus (outside the yard and gap) and then have another lug feed the yard North rail. The other lug would be bare, and the off position.
Using two separate, center-off SPDTs (not DPDTs) for the south and north yards, how can I wire them so that the yards operate independently of each other - and independently of a separate mainline direction, center-off DPDT? Both yard tracks lead into one of these loops, separated by a manually-operated DCC-friendly Walthers/Shinohara turnout. My layout is DC.
That mainline DPDT controls the entire layout and, in conjunction with another DPDT, operates the double reverse loops. I understand I could probably use SPSTs, but SPDTs are what I have in quantity - and used successfully for two years to power a nearly identical yard configuration on a former layout - so no need to recommend them. The yard wiring I used on the old layout doesn't seem to want to work here! I tried attaching the PDF schematic to make it easier to visualize the layout and wiring configuration, but I kept getting an error message. I notified an administrator a few days ago and am awaiting a reply.
I gapped the north rail of each yard track between the end of turnout #10 that leads directly into the yards and the end of the yards. However, when I wired a switch's center lug to a gapped rail and one end lug to the power pack, I got only one-way polarity within the yard. To get two-way polarity within the yard, I also had to toggle the mainline direction DPDT - an extraneous motion I want to eliminate so that I only need to toggle a SPDT and be able to run locos into and out of the yards. My objective: to make each yard either "dead" or "alive" and electrically separate from the other - and separate from the mainline DPDT. How should I wire the two SPDTs to achieve this? Wire all three lugs or only two? To what? Gap more rails and/or add feeders? If so, where? Thanks for your help!