Dan,
Well, I took up skydiving instead of messing with all those wires!
Actually, this simple solution:
- center lug of each SPDT wired to its respective yard rail
- top lug of north yard SPDT wired to bottom lug of the south yard SPDT and
- bottom lug of south yard SPDT wired to the negative bus
Works like a charm!
Kerry
GNMT76 Gentlemen, Thanks to all who contributed to addressing the question here. Problem solved!
Gentlemen,
Thanks to all who contributed to addressing the question here. Problem solved!
What'd you end up doing?
-Dan
Builder of Bowser steam! Railimages Site
Henry
COB Potomac & Northern
Shenandoah Valley
BigDaddy I think so.
I think so.
gregc diagram from HOmainline south yard SPDT center terminal needs to be connected to gapped south rail (this is different from north yard SPDT. based on diagram, mainline DPDT has no function if all mainline tracks are connected to the mainline DPDT the same way, i don't know how direction is controlled on mainline if mainline DPDT is intended to control direction on all mainline and yard tracks corner terminals should be "cross wired" as shown in diagram below and connections A and F connected to top 2 terminals that motor is connected to below, along with any other mainline track connections
diagram from HOmainline
if mainline DPDT is intended to control direction on all mainline and yard tracks corner terminals should be "cross wired" as shown in diagram below and connections A and F connected to top 2 terminals that motor is connected to below, along with any other mainline track connections
Greg,
1. Great! That's what I'm looking for. I'll then connect the south yard's SPDT center lug to the gapped south rail.
2. I didn't bother to show the cross wiring - or the wiring for the other four lugs - on the mainline DPDT because I mentioned a few times before that it - and the reverse loop DPDT - have been functioning flawlessly for two years now (and continue to do so) and because it's also not the (direct) focus of my question, though, of course, it's critical.
Granted, however, without showing the cross and top & bottom lug wires in my diagram, it is misleading. Guilty as charged!
So, both DPDTs are cross-wired, and all six lugs on each are properly wired for mainline and reverse operations.
3. See no. 2
Other than that and Randy's south yard/SPDT correction, how's it look? Ready to go?
rrinker Based on that drawing - the mainline DPDT only functions as a terminal strip to join the wires. Also missing a wire from the South Yard SPDT to the South Yard isolated rail. --Randy
Based on that drawing - the mainline DPDT only functions as a terminal strip to join the wires.
Also missing a wire from the South Yard SPDT to the South Yard isolated rail.
--Randy
Randy,
On your first point above, more comments coming soon.
As to your second: I'll make that correction. Thanks!
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
greg - Philadelphia & Reading / Reading
rrinkerin fact if the siding and main are set to opposite directions and metal wheels or a powered loco or lighted car crosses the gaps, it's a short.
Another reason to go DCC,
Henry running and ducking
That does not make the direction independent on each of those sections, it just allows you to cut power and park a train on any of those tracks with a toggle between the raila nd the power, which is as much as you can do with SPDT.
But as I said way back, there's little point having a center off directional DPDT toggle for each yard/siding, there's generally no need to change the direction on just a siding but not the connected main - in fact if the siding and main are set to opposite directions and metal wheels or a powered loco or lighted car crosses the gaps, it's a short.
gregc rrinker If you want the yard direction to be independent of the main lien direction controleld by the DPDT, then you must gap BOTH rails and use DPDT toggles wired for reversing to feed the yard, he doesn't
rrinker If you want the yard direction to be independent of the main lien direction controleld by the DPDT, then you must gap BOTH rails and use DPDT toggles wired for reversing to feed the yard,
he doesn't
How do you propose using a SPDT toggle to reverse the polarity of the yard with only one rail gapped? Only if you feed the SPDT froom the power pack side of the DPDT reversing switch, then you cna use the power pack reversing switch, but that will still reverse the main line direction as well, unless you flip both the power pack direction switch and the DPDT at the same time.
Besides using a variable AC power supply and a pair of diodes wired in opposite directions to the outer terminals of the SPDT, with the center lug going to the insulated rail, and the common fed fromt he other side. Half wave DC isn't the most healthy, but absent coreless motors it shouldn't really hurt anything. But that's a rather silly way to go about things. Since the layout is only suitable for single train operation, I don;t see what the big deal is about flipping the DPDT toggle to change direction of the train when it's in the yard. Those extra sidings could also use a SPDT to isolate them, allowing a train to be parked there and shut off so another can pass. Of course only SPST toggles are really needed, but since the OP has a supply of SPDT - just use those. Leave on end unconnected. Done.
NeO6874 HOmainline I better visualize such things when I can see the actual lugs and their wires leading to wherever.
HOmainline
I better visualize such things when I can see the actual lugs and their wires leading to wherever.
Got it, Dan. Thanks for the drawing.
I did that a few days ago and then realized the yards are still under the control of the mainline DPDT. It's an acceptable solution and one that I may stick with. And it may well have been the setup I used on the old layout, though probably forgot about after eight months of no trains.
I'm trying out Rinker's yard-DPDT solution as well.
HOmainlineI better visualize such things when I can see the actual lugs and their wires leading to wherever.
Here's the SPDT wiring then ...
rrinkerIf you want the yard direction to be independent of the main lien direction controleld by the DPDT, then you must gap BOTH rails and use DPDT toggles wired for reversing to feed the yard,
rrinker SInce there is a reversing section ont he alyout, that is why there is the DPDT wired as a direction switch. SO you have main lien direction and reverse loop direction independent - one is the power pack's reversing switchmt he other is the added DPDT. To change direction of trains in the yard - one of these direction switches has to be oeprated. That's just the way DC works. If you want the yard direction to be independent of the main lien direction controleld by the DPDT, then you must gap BOTH rails and use DPDT toggles wired for reversing to feed the yard, you can't make this work with one power pack and SPDT switches, it's not electrically possible. Frankly, it doesn't sound workable with oen power pack anyway, why would you have a train in the yard go one way and a train ont eh main go the other, powered by the same power pack? It's not like you can have one train circling the main and do switching in the yard at the same time with only one power pack. TO simply cut power int he yard independent of the main, the SPDT is fine, and any of the diagrams already presented are the wya to wire it. However, if you feed the SPST from the main track side of the DPDT, then the DPDT will control the direction in the yard. This is how it normally would work. This is how it works on any of the Atlas track plans with reverse loops if you use their control components as shown in their books as well. If you have 2 power packs, it's actually still the same. EACH power pack needs a second direction switch (DPDT) because of the reversing loop, and the DPDT is what controls the direction of a train anywhere on the main OR IN THE YARDS. The power pack's reverse switch is used just in the reverse loop section. Remember with DC, when in a reverse loop, you flip the polarity of the entire rest of the layout (hence the DPDT switch) so the train can exit the reverse loop and not short. --Randy
SInce there is a reversing section ont he alyout, that is why there is the DPDT wired as a direction switch. SO you have main lien direction and reverse loop direction independent - one is the power pack's reversing switchmt he other is the added DPDT. To change direction of trains in the yard - one of these direction switches has to be oeprated. That's just the way DC works. If you want the yard direction to be independent of the main lien direction controleld by the DPDT, then you must gap BOTH rails and use DPDT toggles wired for reversing to feed the yard, you can't make this work with one power pack and SPDT switches, it's not electrically possible. Frankly, it doesn't sound workable with oen power pack anyway, why would you have a train in the yard go one way and a train ont eh main go the other, powered by the same power pack? It's not like you can have one train circling the main and do switching in the yard at the same time with only one power pack. TO simply cut power int he yard independent of the main, the SPDT is fine, and any of the diagrams already presented are the wya to wire it. However, if you feed the SPST from the main track side of the DPDT, then the DPDT will control the direction in the yard. This is how it normally would work. This is how it works on any of the Atlas track plans with reverse loops if you use their control components as shown in their books as well.
If you have 2 power packs, it's actually still the same. EACH power pack needs a second direction switch (DPDT) because of the reversing loop, and the DPDT is what controls the direction of a train anywhere on the main OR IN THE YARDS. The power pack's reverse switch is used just in the reverse loop section. Remember with DC, when in a reverse loop, you flip the polarity of the entire rest of the layout (hence the DPDT switch) so the train can exit the reverse loop and not short.
Thanks for the additional details.
A little background for review: this new layout is nearly identical (and a little larger) to the one I tore down in January. It's got an added mainline run, a short yard off to the west and a slightly different confiruration of turnouts nos. 8, 9 and 10 in the layout schematic shown some number of posts above. The two DPDTs controlling the mainline and the reverse loops - and their respective operations - worked flawlessly on the old layout and continue to do so now.
It's basically a one-train operation with very limited opportunity to run a second loco (a switcher) and a short train in the loops or have one sitting on a siding. One power pack provides the juice, and another powers nine Tortoises.
I was train-less for some eight months while planning and building the new layout and, so, certainly may have some fuzzy memories about what did what for the two years previous. All your collective comments and the mini education above have helped to bring some of those back.
And yep, I do understand that mainline trains and yard trains can only run in the same direction, controlled as they are by the mainline DPDT. Cutting power in one or both yards is indeed one of my objectives. I've wired two sidings on the north side to just that to to allow a a train to pass on the newly laid mainline north of them while any train on a siding takes a break.
gregc sounds like you're not familiar with reading schematics in the schematice representation of the DPDT switch on the right below, there are six terminals, the circles. The three on the top are the same as for an SPDT switch. So the DPDT has 2 SPDT. The dashed line shows that they are connected mechanically. in the reversing switch diagram on the left, the 3 terminals on the left are effectively 1 SPDT and the 3 terminals on the right a 2nd SPDT. the 3 terminals on the left in the left diagram are represented by the the 3 terminals on the top in the right diagram and similarly the right 3 and bottom 3. the center terminals in the left diagram connected to the power supply are the left most terminals in the right diagram. the schematic (right) shows that the left terminal with the diagonal lines going up and right can make contact with one of the 2 terminals on the right which are the top and bottom (left) terminals on the left diagram. is your DPDT reversing switch wired this way? or are the power supply and motor terminals reversed?
sounds like you're not familiar with reading schematics
in the schematice representation of the DPDT switch on the right below, there are six terminals, the circles. The three on the top are the same as for an SPDT switch. So the DPDT has 2 SPDT. The dashed line shows that they are connected mechanically.
in the reversing switch diagram on the left, the 3 terminals on the left are effectively 1 SPDT and the 3 terminals on the right a 2nd SPDT.
the 3 terminals on the left in the left diagram are represented by the the 3 terminals on the top in the right diagram and similarly the right 3 and bottom 3.
the center terminals in the left diagram connected to the power supply are the left most terminals in the right diagram. the schematic (right) shows that the left terminal with the diagonal lines going up and right can make contact with one of the 2 terminals on the right which are the top and bottom (left) terminals on the left diagram.
is your DPDT reversing switch wired this way? or are the power supply and motor terminals reversed?
Henry,
It took just a few minutes of looking at your first diagram to figure out the relationship between the circles and terminals (lugs). I better visualize such things when I can see the actual lugs and their wires leading to wherever.
My reverse loop DPDT is wired similarly to the one in the diagram, but with two additional wires leading to their respective loop tracks.
Thanks for the above elaboration too!
BigDaddy gregc See the 4 circles vertically in a row, just to the right of throttle SW ? Imagine the middle two are just one. Those are the 3 lugs on 1/2 of a DPDT switch divided down the middle. Notice the top circle goes to the rail that is gapped. Rereading your posts, I have no idea if that is the north or south rail is gapped nor if the same rail is gapped in the second yard. Whatever lug that feeds the mainline rail that is gapped has to feed the SPDT switch too. In Greg's diagram it is the same side rail in both yards.
gregc
I appreciate the explanation! On my layout, the north rail in each yard is gapped.
gregc in the diagram below, the track is connected to what is shown as a motor presumably you know which 2 terminals on the SPDT switch to use.
in the diagram below, the track is connected to what is shown as a motor
presumably you know which 2 terminals on the SPDT switch to use.
A handsome looking schematic indeed! The two DPDTs (mainline and double reverse loop) have long been wired and operating perfectly.
If you have a drawing in this format that illustrates your earlier schematic, send it along.
I also just replied to your PM.
Many thanks for the schematic! It really helps.
I've hand-drawn a color and lettered "translation" of how I see it from the viewpoint of the DPDT's lugs and the two SPDTs' lugs. It's easier for me to visualize that way. I've saved it as both a JPEG document and a PDF document.
I don't see a way to attach docs here, though I believe I can do so via a PM. Let me know when you've received it and whether I got it right and where any corrections need to be made.
Beat me to the picture, Greg