gregc SeeYou190 If you do not have the rectifier you will need to either stop the train in the reversing section, or flip the direction switch on the power pack and the DPDT to the reversing section simultaneously. i thought the common approach (Linn WestCott) is NOT to use the direction switch on the throttle and have separate reversing switches for the mainline and reversing section(s) connected to the throttle. with separate mainline and reversing-section reversing-switches for each throttle a single reversing-switch can be used for all reversing sections. with the reversing-section switch properly set to match the mainline polarity for the route entering the reversing-section, the mainline reversing-swith is toggled after the train completely enters the reversing section and the turnout switched so the train can re-enter the mainline from the reversing-section. i don't understand the need for a "rectifier". (the reversing-section reversing-switch is connected to the throttle and is independent of the mainline polarity)
SeeYou190 If you do not have the rectifier you will need to either stop the train in the reversing section, or flip the direction switch on the power pack and the DPDT to the reversing section simultaneously.
i thought the common approach (Linn WestCott) is NOT to use the direction switch on the throttle and have separate reversing switches for the mainline and reversing section(s) connected to the throttle. with separate mainline and reversing-section reversing-switches for each throttle a single reversing-switch can be used for all reversing sections.
with the reversing-section switch properly set to match the mainline polarity for the route entering the reversing-section, the mainline reversing-swith is toggled after the train completely enters the reversing section and the turnout switched so the train can re-enter the mainline from the reversing-section.
i don't understand the need for a "rectifier". (the reversing-section reversing-switch is connected to the throttle and is independent of the mainline polarity)
Actually it is/was common DC practice to use all three reversing switches.
Using the added main and reverse loop switches as "system" switches and using the power pack or throttle switch to change direction during actual switching moves, etc.
A few post back is an explanation of the rectifier approach, a whole different way to control a reverse loop with its own set of limitations.
Sheldon
To begin with, neither of my Atlas twin switches work. I used a DVM to check output voltage and polarity from both. I applied voltage to the input terminals and measured output on each switch in the three possible positions. Very erratic output. Going to go with simple DPDT 6 post switches.
Dave
gregci thought the common approach (Linn WestCott) is NOT to use the direction switch on the throttle and have separate reversing switches for the mainline and reversing section(s) connected to the throttle.
Yes, That was the approach that Linn Wescott promoted. When he suggested this, walkaround DC throttles did not exist, and this approach was easier.
With walkaround DC throttles, having a seperate mainline and reverse loop direction switches became less practical.
The OP wanted simple, and I just put out one option that is simple to control and fairly easy to build.
Dave KGoing to go with simple DPDT 6 post switches.
That sounds like a good idea.
-Kevin
Living the dream.
all of the ideas discussed in this thread would make a good chapter in Best Book about Wiring a Layout
greg - Philadelphia & Reading / Reading
gregc all of the ideas discussed in this thread would make a good chapter in Best Book about Wiring a Layout
Years ago I started writing a book about my Advanced Cab Control system, and advanced DC ideas in general. Then life got busy again and it sits unfinished.
I will return the Atlas junk. I purchased four DPDT switches to control my two turnbacks.
Lastspikemike The latest Atlas product is made in China. I bought a 220 controller which was completely dud right out of the packaging. I took my multimeter to the same hobby shop to test a second brand new one out of the sane shipment before buying, in order to save a trip. Tested the circuits as per Atlas schematic right in front of the store Owner. Complete dud as well. The problem seems to be in the spring switch aspect of the plastic sliders. The electrical contact clearance (air gap) inside the switch must be tiny and if the plastic mouldings are poor there's no way they can build them consistently to work properly. Atlas Made in the USA switches work really well, even when quite old. Current Atlas QA leaves a lot to be desired apparently. Atlas Twin Switch replaces the function of the powerpack reversing switch. For common rail designs I think you need to use the reversing switches closest to the track power and not use the powerpack reversing switch at all.
The latest Atlas product is made in China. I bought a 220 controller which was completely dud right out of the packaging. I took my multimeter to the same hobby shop to test a second brand new one out of the sane shipment before buying, in order to save a trip. Tested the circuits as per Atlas schematic right in front of the store Owner. Complete dud as well. The problem seems to be in the spring switch aspect of the plastic sliders. The electrical contact clearance (air gap) inside the switch must be tiny and if the plastic mouldings are poor there's no way they can build them consistently to work properly.
Atlas Made in the USA switches work really well, even when quite old. Current Atlas QA leaves a lot to be desired apparently.
Atlas Twin Switch replaces the function of the powerpack reversing switch. For common rail designs I think you need to use the reversing switches closest to the track power and not use the powerpack reversing switch at all.
As much as I am a fan of Atlas track, I have never cared for their wiring devices or their promoted wiring system, even back in the 70's when I worked in the hobby shop.
gregcAll of the ideas discussed in this thread would make a good chapter in Best Book about Wiring a Layout
Greg, one of the items I think people should ask themselves when deciding to use DC or DCC to control a layout is if they have enough DC knowledge to design, install, and troubleshoot the system all by themselves.
There are just too few people left that can help with complex DC systems, and the books, all written decades ago, were for a different audience.
SeeYou190 gregc All of the ideas discussed in this thread would make a good chapter in Best Book about Wiring a Layout Greg, one of the items I think people should ask themselves when deciding to use DC or DCC to control a layout is if they have enough DC knowledge to design, install, and troubleshoot the system all by themselves. There are just too few people left that can help with complex DC systems, and the books, all written decades ago, were for a different audience. -Kevin
gregc All of the ideas discussed in this thread would make a good chapter in Best Book about Wiring a Layout
That's partly why I started to write a book, and maybe one day I will finish it, after the layout is built.
This was a bad week for construction progress here at home, but this weekend looks promising.
Kevin, it sounds like you and I use a lot of similar wiring methods, one day after the pandemic we must get together in person.
ATLANTIC CENTRALKevin, it sounds like you and I use a lot of similar wiring methods, one day after the pandemic we must get together in person.
We share a great many similarities.
1954, no Big-Boys, DC control, private roadnames, no foam, etc.
I would love to meet up if there is ever another Timonium show!
Guys,
My other hobby is restore Chevy Corvettes so I have plenty of knowlege with simple 12volt systems. I do not consider my layout with two turnbacks to be complex. I have been away from model railroading for a long while and need to catch up on the electric side.
Dave K Guys, My other hobby is restore Chevy Corvettes so I have plenty of knowlege with simple 12volt systems. I do not consider my layout with two turnbacks to be complex. I have been away from model railroading for a long while and need to catch up on the electric side. Dave
No worries, everyone is just trying to understand both what you have, and what your goals are.
I'm pretty deep into some really advanced DC, with wireless throttles, signals, detection, one button route control. I never assume a correct answer until I know what I'm dealing with, so I tried to just let the others help - mostly.
I'm a car guy from way back, worked on a lot od Chevy's, and other stuff.
Restored and built this little hot rod in 1976:
1963 Nova SS convertible - only made that year, never made with a V8 but easily converted with 64 and later parts.
283, Corvette heads and cam, Torker, 600 Holley with vac secondaries, headers/Corvair turbo duals, 4 speed - and a unique drive line that worked well for such a light car - M20 with the low 1st gear, 3.08:1 rear axle.
Enough starting ratio, but lots of top end.
0-60 - 5.5 sec
1/4 mile - under 14 sec
Top end - my 160 mph Corvette speedo said 135 mph and it was still pulling in 4th gear - that was fast enough in the little unibody convertible.
Fuel economy - driven like you had any sense - 20 mpg highway
Today I just drive a factory hot rod of sorts - 2015 FORD FLEX LIMITED w/ecoboost - almost the same performance stats as the Nova......
Had lots of other hot roads over the years.......
LastspikemikePlus it seems none of us were alert to what your difficulty actually was. Sorry about that.
So now you are speaking for the group?
This is a great forum and I like everyone's help. I will stay connected as I am sure to have more questions.
I have installed two DPDT (center off) switches. One for the main track and on for the gapped turnback. What is the process to reveres the polarity as the train leaves the main line, enters thr turnback and leaves turnback back on to main line?
Regards
Dave K.
Dave K What is the process to reveres the polarity as the train leaves the main line, enters thr turnback and leaves turnback back on to main line?
Dave,
I am starting a new thread.
Stand by...
I gave up n the two DPDT switches to control the turnback and have gone back to one. Still having difficulty synchronizing the DPDT switch when the train leaves the block and enters the main line.
Dave KI gave up n the two DPDT switches to control the turnback and have gone back to one. Still having difficulty synchronizing the DPDT switch when the train leaves the block and enters the main line.
When using one, you should stop the train in the reversing section, change direction on BOTH the DPDT for the reversing section AND the power pack, then continue as normal.
I hope this works.
I wired the turnback loop DPDT switch as required. Did the same for the main loop switch. The main loop is fine but the turnback switch is shorting somewhere? I am getting a reading when the switch is in the middle and a short in one of the up positions. I tried to reveres wires in many combinations and chenger switches, all to no avail.
Sounds reasonable. And I thought my layout was simple?
Dave K Sounds reasonable. And I thought my layout was simple? Dave
No layout, DC or DCC powered, that is a small oval and has reverse cutoffs thru the middle is simple from an electrical standpoint.
That is why I would still like to see a drawing of the track plan and not try to figure the track plan out from a few photos.
That is why I have not said "Dave, do this, or do that".
Mike means well, but I'm not sure him or anyone completely understands what your needs are without seeing a map of your track.
I have been an electrcian and electrical control system designer for the last 40 years, and been building DC powered model train layouts for 50 years, and without a track plan, I don't see how anyone can truely give you a complete solution to your problems.
Which is evidenced by the fact that you are still having problems.
Pictures
More pictures
The turn back under the bridge is not connected and is isolated from all other track work. What is confusing why does the turnback block DPDT short in only one direction but the one for the main line does not short? Isy connecting all of the other feeders in parallel pose a problem?
Dave, A good approach at this point would be to disconnect all the feeder to the track. Then reconnect them one at a time and see when the shorting problem is present again.
Thanks to all of you.
I have figured out how to use the two DPDT switches to get through the 1st turn back but since I do not want to use the throttle diI hrectional switch, how do I add a 3RD dpdt for the main line feeders?
Presently, my layout has one turnback and a main line. I have plans for a 2nd turnback. I have the turnback wiring in a block with DPDT switch and the section of track leaving the turnback gapped to control by a 2nd DPDT switch. I do not want to use the throttle to control polarity when the train moves into the main line so I plan to add a 3rd DPDT switch. I assume that I should have terminal boards for both power in from throttle (+/-) and power to DPDT's, and from from DPDT's to track feeders?Regards,