Who makes a good relay for analog train operation?
Regards,
Dave K.
A simple center-off, DPDT toggle switch does the trick nicely, changing the polarity in the loop just as Mike described.
With DC, if you plan to reverse the loop polarity, you need to stop the train, reverse the loop polarity, reverse the throtte polarity, then restart the train.
So yes, you can create a semi automatic situation where the turnout position controls the entry/exit polarity, but at some point while the train is in the loop, it has to stop and let the turnout be thrown and the throttle direction reversed for the other direction on the mainline.
Otherwise, when you throw the turnout, the train will change direction.
Sheldon
Lastspikemike ATLANTIC CENTRAL With DC, if you plan to reverse the loop polarity, you need to stop the train, reverse the loop polarity, reverse the throtte polarity, then restart the train. So yes, you can create a semi automatic situation where the turnout position controls the entry/exit polarity, but at some point while the train is in the loop, it has to stop and let the turnout be thrown and the throttle direction reversed for the other direction on the mainline. Otherwise, when you throw the turnout, the train will change direction. Sheldon This turns out to be incorrect. Took me a little while to figure out. The key aspect is to provide sections of main line powered track inside the actual geometric reversing loop long enough to hold the entire locomotive consist. This requires the reversing section to be shorter than might otherwise fit within a loop created by one turnout. For our back to back loops which basically have a long double isolated X section these main line powered sections are very long so there's practically no limit to train length, but for our one single turnout loop we sacrifice a little train length capacity to allow for these main line powered sections. A section of track long enough to contain the locomotive consist just before the exit to the loop is all that is required. For a two way loop you need the same length of main line powered track at the other end of the reversing section. Each one of these sections forms one of the two routes out of the turnout. The turnout also sets polarity in the reversing section to match train direction entering the loop. The train proceeds into the loop and passes onto the reversing section proper. When the whole powered part of the train (which is the whole thing if you use metal wheels) is within the reversing section, I.e. has cleared the entry section of track powered by the mainline, you switch polarity of the main line, as the locomotive consist clears the reversing loop onto the second section of main line included inside the loop only then do you throw the turnout which changes the polarity in the reversing section. The locomotives don't change direction and the trailing car wheels don't short out the isolating gaps. It's all in the timing of the polarity changes. Should work fine for DCC in fact. I think for DCC the mainline sections aren't needed but I'm still thinking about that. DCC allows you to flip " polarity" inside the reversing loop whenever you like. The steel wheel effects from the trailing cars might be an issue though. This all results from the Möbius Strip aspect of a reversing loop where one rail is always a continuation of the opposite rail. A reversing loop is made from one rail. Magical in a way. You never need to stop the train.
ATLANTIC CENTRAL With DC, if you plan to reverse the loop polarity, you need to stop the train, reverse the loop polarity, reverse the throtte polarity, then restart the train. So yes, you can create a semi automatic situation where the turnout position controls the entry/exit polarity, but at some point while the train is in the loop, it has to stop and let the turnout be thrown and the throttle direction reversed for the other direction on the mainline. Otherwise, when you throw the turnout, the train will change direction. Sheldon
This turns out to be incorrect. Took me a little while to figure out.
The key aspect is to provide sections of main line powered track inside the actual geometric reversing loop long enough to hold the entire locomotive consist. This requires the reversing section to be shorter than might otherwise fit within a loop created by one turnout. For our back to back loops which basically have a long double isolated X section these main line powered sections are very long so there's practically no limit to train length, but for our one single turnout loop we sacrifice a little train length capacity to allow for these main line powered sections.
A section of track long enough to contain the locomotive consist just before the exit to the loop is all that is required. For a two way loop you need the same length of main line powered track at the other end of the reversing section. Each one of these sections forms one of the two routes out of the turnout.
The turnout also sets polarity in the reversing section to match train direction entering the loop. The train proceeds into the loop and passes onto the reversing section proper. When the whole powered part of the train (which is the whole thing if you use metal wheels) is within the reversing section, I.e. has cleared the entry section of track powered by the mainline, you switch polarity of the main line, as the locomotive consist clears the reversing loop onto the second section of main line included inside the loop only then do you throw the turnout which changes the polarity in the reversing section. The locomotives don't change direction and the trailing car wheels don't short out the isolating gaps.
It's all in the timing of the polarity changes. Should work fine for DCC in fact. I think for DCC the mainline sections aren't needed but I'm still thinking about that. DCC allows you to flip " polarity" inside the reversing loop whenever you like. The steel wheel effects from the trailing cars might be an issue though.
This all results from the Möbius Strip aspect of a reversing loop where one rail is always a continuation of the opposite rail. A reversing loop is made from one rail. Magical in a way.
You never need to stop the train.
That is really the same thing with gaps in different places. You are still reversing the main and throwing the turnout in any case. And you failed to explain that little wrinkle of the mainline polarity extending into the loop to the OP, I bet that was not on his radar.
You are simply controlling the polarity of the reversing section with the turnout position ahead of the mainline reversing switch. Nothing new there. You then of course need a throttle location reverse switch to back up inside the reversing section.
And this is all great if you can see the train easily to know it has moved from the reverse section to the mainline fed section. Many great layouts I have operated on have hidden reverse loops and they easily work fine with two separate switches, using minimal detection or train locating methods.
For all that "timing" you are suggesting one might as well do it the conventional way and simply have separate reversing switches for the loops.
Set them correctly to enter the loop, reverse the main while the train is in the loop, throw the turnout and exit the loop, all easily done in the time it takes and normal train to travel around any usable sized reverse loop.
But since I don't have time to draw a bunch of diagrams today, or this week, once again I will leave you to it.
And, for what it is worth, my layout is full of X sections. They are used at every mainline interlocking to eliminate unnecessary blocks.
Gents:
I am researching an Alastranz turnback relay with an infrared sensor. I would prefer an automated process but it starting to get complicated.
Dave
I meant to say Azatrax. I am going to try the Atlas switch method first.
Thanks to all.
Curious why you want an "analog" or manual reverse loop switch. I have enough problems avoiding running thru closed turnouts to risk having to throw a toggle switch every time one of my trains enters the reverse loop. I plan to install the Azatrax IR detector to handle one turnout at my "yard" that I constantly forget to throw after the train leaves.
Plug-n-Play Digitrax AR1 and NCE AR10 reversers handle reverse loops perfectly with no intervention. Two wires to the reverse loop tracks, nothing exotic, no sensors needed, etc. Just run the trains. I've used both.
-- Chuck
Chuck S Curious why you want an "analog" or manual reverse loop switch. I have enough problems avoiding running thru closed turnouts to risk having to throw a toggle switch every time one of my trains enters the reverse loop. I plan to install the Azatrax IR detector to handle one turnout at my "yard" that I constantly forget to throw after the train leaves. Plug-n-Play Digitrax AR1 and NCE AR10 reversers handle reverse loops perfectly with no intervention. Two wires to the reverse loop tracks, nothing exotic, no sensors needed, etc. Just run the trains. I've used both. -- Chuck
Because the original poster is running DC, not DCC, so a DCC auto reverser will not work.
That is what he meant by "analog train operation", his trains are "analog", not digital.
Thanks, and sorry for posting bad information. I was under the impression the autoreversers would work on either DC or DCC but it ain't so! DCC is so simple I forgot some folks like to or at least have to throw dozens of switches to run a couple of trains. Back into trains a couple of years ago and DC was never a consideration.
Chuck S Thanks, and sorry for posting bad information. I was under the impression the autoreversers would work on either DC or DCC but it ain't so! DCC is so simple I forgot some folks like to or at least have to throw dozens of switches to run a couple of trains. Back into trains a couple of years ago and DC was never a consideration.
Chuck, I understand why you like DCC, and I have lots of experience using DCC. But I am building a new layout, 1500 sq ft, 450' double track mainline, 8-10 operators in play, staging for 30 trains, 40-50 car train lengths, and it will be DC.
And guess what? There will not be one block toggle.
There will be walk around operation with radio throttles, detection, signaling, CTC, ATC (if you run a red single your train stops), one button turnout route control.
As a guest operator on my layout you would likely push less buttons than on a similar DCC layout.
For more info look for my thread about my track plan.
In fact. You might be surprised at the percentage of modelers in HO and N with moderately large layouts who still use DC. Every casual survey we have taken on here, some fairly recent, puts DC use still at 40-45% and not likely to change.
How do I operate the snap switch? In other words the left and right buttons as the train approaches the reversing loop, in the loop, and exiting the loop?
Dave KWho makes a good relay for analog train operation?
Dave KI am researching an Alastranz turnback relay with an infrared sensor. I would prefer an automated process but it starting to get complicated.
Dave KHow do I operate the snap switch? In other words the left and right buttons as the train approaches the reversing loop, in the loop, and exiting the loop?
Hello Dave.
I am trying to figure out your question, and filter out the noise in the responses.
It sounds like you have a turn-back reverse loop at the end of your run, and you want to turn the train around in the loop, without stopping, and return on the same track.
You want control of this reverse loop to be simple and preferably automatic.
Is this correct? If not, can you explain your goals a bit more?
Are you comfortable bulding a DC control system for this, or do you need to use something off the shelf?
Is it OK to have a complicated system as long as control is simple, or would you prefer to build something simple and have it a bit more fiddly to control?
I can help, I have done such a thing on real layouts, but I need to understand exactly what your goals are.
Let me know. I am here to help.
I will check back in a few hours when I have time this evening.
-Kevin
Living the dream.
Kevin,
You are correct. A smple turn back using DC analog power. I am using Atlas snap switched to accomplish the reveres polarity control.
Dave K Kevin, You are correct. A smple turn back using DC analog power. I am using Atlas snap switched to accomplish the reveres polarity control. Dave
Dave, Why is it important to you to try an automate the reverse loop function?
Good DC practice suggests that the reverse switch positon for the mainline should refect the "EAST - WEST" direction of travel, so even with some semi automation of the loop you will need to throw the mainline reverse switch.
I use DC, very complex DC with detection, signals, one button route control, CTC, walk around radio throttles - and I avoid reverse loops as much as possible.
I'm getting ready to start on this basement filling layout - there will only be two reverse loop situations - neither is part of the mainline:
I would be interested to see you track plan and offer my thoughts on a total wiring solution.
Dave KYou are correct. A smple turn back using DC analog power. I am using Atlas snap switched to accomplish the reveres polarity control.
Which do you prefer?
1) Simpled to install, but not as simple to use.
2) More involved to build, but simple to use.
Also, I never use Atlas wiring components. I prefer full size toggle switches.
I have wired the Atlas switches as required. Purchased two. The center slide position shoul be off, yet my center position on both is showin power out? The down position is off. Are these faulty switches?
K.
Dave K I have wired the Atlas switches as required. Purchased two. The center slide position shoul be off, yet my center position on both is showin power out? The down position is off. Are these faulty switches? Dave K.
Well Dave, without a wiring diagram showing what you have done, it is hard to say.
Dave,
Before this discussion swirls any further down, can you please provide a track plan, wiring diagram, and any pictures?
You can email them to me if you want to.
I will do that. I am not sine powere turnout switches but snap switches for turnback control.
The problem involves the turnback polarity control and reversal. It has nothing to do with the turnouts as they are all manual. I've included some pictures of my layout (work in progress) emphasising the turn back with the bridge in the middle. plastic gap joiners installed at the beginning and end of the turnback. Feeder in the middle. The issue is how to reverse polarity using the Atlas snap switches. I am trying to send pictures.
I sent you an email plus pictures.
I once created a DC reverse loop controller that was so simple, I'm surprised I've never seen it in print. The only downside is that the train had to go through the loop in the same direction, but in my case, both loops were hidden, so it was a non-issue ....
All I used was a single bridge rectifier. The main track power was connected to the two AC terminals and the loop power was connected to the + and - terminals. Once in the loop, the train would continue moving forward regardless of which direction the reversing switch was thrown.
All you had to remember was that the train must enter the right leg of the loop turnout (for example). Once the engines were in the loop, the direction switch is thrown allowing the engines to leave the loop without stopping.
Three downsides (which were negligeable to me) - 1. train can only travel in one direction around the loop. 2. you cannot change direction in the loop. 3. There is a 1.5 volt drop in track power IN the loop, which is barely noticeable at track speed.
Mark.
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Dave KI sent you an email plus pictures.
Here are Dave's Pictures:
There are two crossovers in an oval.
Mark R. I once created a DC reverse loop controller that was so simple, I'm surprised I've never seen it in print. The only downside is that the train had to go through the loop in the same direction, but in my case, both loops were hidden, so it was a non-issue .... All I used was a single bridge rectifier. The main track power was connected to the two AC terminals and the loop power was connected to the + and - terminals. Once in the loop, the train would continue moving forward regardless of which direction the reversing switch was thrown. All you had to remember was that the train must enter the right leg of the loop turnout (for example). Once the engines were in the loop, the direction switch is thrown allowing the engines to leave the loop without stopping. Three downsides (which were negligeable to me) - 1. train can only travel in one direction around the loop. 2. you cannot change direction in the loop. 3. There is a 1.5 volt drop in track power IN the loop, which is barely noticeable at track speed. Mark.
I have seen it in print and seen it in use before, works well if you can except those limitations.
I would have to dig thru a few old books that are currently packed up to find who published it.
ATLANTIC CENTRAL I have seen it in print and seen it in use before, works well if you can except those limitations. I would have to dig thru a few old books that are currently packed up to find who published it. Sheldon
Believe me, I wasn't laying claim to inventing the idea. Being so simple, surely somebody long before me had to have come up with it. But I will admit, I came up with it on my own without having seen it in print prior to.
Mark R.Believe me, I wasn't laying claim to inventing the idea. Being so simple, surely somebody long before me had to have come up with it. But I will admit, I came up with it on my own without having seen it in print prior to.
I had also never seen it in print. One of the "old guys" at Scale Rails Of Southwest Florida suggested it to me as a simple solution on the club's N scale layout.
It works.
ATLANTIC CENTRALI have seen it in print and seen it in use before, works well if you can except those limitations. I would have to dig thru a few old books that are currently packed up to find who published it.
Expanding on this possible solution, I would suggest Dave do this to solve the problem:
This uses a bridge rectifier and a reversing DPDT switch (center-off if you want to park a train) to control train direction in the reversing section.
This is simple to control, and there is no need to stop the train. It is also fairly straightforward to build.
The biggest draw-back is that the train will slow in the reversing section a bit because of the voltage drop in the rectifier diodes.
Still awaiting from others?
I do not want to complicate thing with a bridge rectifier. Just want to use a transformer and a twin switch for polarity reversal.
Dave KI do not want to complicate thing with a bridge rectifier. Just want to use a transformer and a twin switch for polarity reversal.
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.
The reason for the rectifier is to allow the DPDT reversing switch to control the reverse section independent of the controller direction position. As the train goes through the reversing section the direction switch on the controller can be flipped without affecting the direction of the train in the reversing section.
This is simpler to control, which is a preference for me.
You would need a separate DPDT switch for each reverse section, but they could be supplied by the same rectifier.
When I build my layouts, I am OK with complicated builds in exchange for simple operation. You might hear the phrase "With DCC you control the train, but with DC you control the track", but, that does not need to be true.
I do not control the track, just the turnouts, which you need to do with DCC as well. The turnout position controls cab selection, signalling, isolation, and power routing.
As described previously, my reverse section has industries on it. All trains must stop and either pick up or drop off a freight car. The first direction change is done with the reverse section DPDT reversing switch. This makes control through the reversing section almost invisible.
There are almost no electrical controls on my panels other than turnout toggles. However, it is more difficult to build this way.
Reading about the Atlas Twin (which I have never used) it is supposedly just two DPDT reversing switches (not center-off) in a plastic housing. It is priced higher than a pair of DPDT Center Off Toggle switches, so I will never use one.
From how it looks to me... you could feed the Atlas Twin from the DC terminals on the recitifer, and use each side of the Atlas Twin to control a reversing section. Someone familiar with the Atlas products will need to verify that this is correct.
Also, another detail I am not sure about, but if the Atlas Twin is not "break before make", I would never consider using it.
SeeYou190If 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)
greg - Philadelphia & Reading / Reading