# Help Required re reverse Loops in new Layout



## RGS K27-461 (Jan 8, 2008)

Hi, I'm using a plan from 101 track plans to build a 80 foot x 40 foot layout. it has a wye and at least one reverse loop. I have marked in RED where i believe my DCC will require a reverse connection. I'm thinking of using a Digitrax PM42 to control the reverse sections and shorts. Any Ideas/feedback greatly appreciated

http://www.narrowgaugerails.com/nar...age_10.htm
I currently have 2 8 Amp Digitrax Command Station/booster combo. but are looking at the Digitrax PM42 to break down each bosster.
There are future plans to have track run over most of the 1.5 acre property.


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## DKRickman (Mar 25, 2008)

Provided that you won't be running two trains through the reverse sections simultaneously, I'd move the gap in the vertical leg of the wye so that it is between the left switch and the branch off the main line at Ridgeway, and add a gap under the high bridge. You have a second reverse loop in there (leave Ridgeway, left through Forks Creek, over the high bridge, through the tunnel, and you're back at Ridgeway) and that would make a single block of track which covers them all. Otherwise, you'll probably want separate reversers for each of the three places where trains can be reversed. 

Remember that the reverser needs an isolated block to work. As drawn (I'm assuming you've marked insulated rail gaps in red) you still have the entire layout as one continuous block. 

Hope this helps, 
Ken


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## RGS K27-461 (Jan 8, 2008)

Thanks Ken, I've marked the blocks where i think they should be using Yellow, the Red marks are for "Reversed so to speak power input and the Green for normal power input. I was thinking of the Digitrax PM42 to get my sub districts/reverse sections.

I know the pic isn't the best but thanks for the input 


Regards 



Phil 

See page in signature below if having trouble with link


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## toddalin (Jan 4, 2008)

And of course you can ignore all that digital stuff and just design the system using relays or LGB EPLs at a fraction of the cost to work in the old fashion way, just as track powered trains have been doing since???

OHHH Post 1500!


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## Greg Elmassian (Jan 3, 2008)

Nope, here I will disagree with you Todd... To be clear, using relays to do this task is like using points and a distributor and a carb to run a modern engine...

The modern autoreversers incorporate smart logic on how to discriminate between a short and a "request for polarity reversal", are programmable, and usually have programmable smarts on delay to restore power after a short, maximum current, etc. 

This is way beyond a simple relay, and the autoreverser I use, that meets this criteria, is about $45... all assembled and ready to go. (Digital Specialties PSX-AR) 

The relays do belong to that "golden age" of DC.... 

Regards, Greg


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## toddalin (Jan 4, 2008)

Posted By Greg Elmassian on 21 Jun 2011 11:40 AM 
Nope, here I will disagree with you Todd... To be clear, using relays to do this task is like using points and a distributor and a carb to run a modern engine...

Regards, Greg 

Nothing wrong with points and a carb. In fact, Chevy rates their brand new big crate engines at _40 hp more with a carb as opposed to their fuel injection_.








You know full well that I could make the system work with relays to mind the polarity and there would be no short circuits to contend with.

Modified Holley 600 double pumper on my '64 Corvette.


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## Cougar Rock Rail (Jan 2, 2008)

Well Todd, 

I've got a 650 double pumper on MY '64 Corvette, and I've wasted many hours setting float levels and doing jetting changes when I could have been out driving...  
Not to mention I once got more MPG with a Cat 3406 pulling 40 tonnes of gravel.... 

Keith 

P.S. What part of "DCC in Large Scale" don't you understand?


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## toddalin (Jan 4, 2008)

Posted By Cougar Rock Rail on 21 Jun 2011 12:21 PM 
Well Todd, 

I've got a 650 double pumper on MY '64 Corvette, and I've wasted many hours setting float levels and doing jetting changes when I could have been out driving...  
Not to mention I once got more MPG with a Cat 3406 pulling 40 tonnes of gravel.... 

Keith 

P.S. What part of "DCC in Large Scale" don't you understand?  

You don't have to understand DCC to wire a track to avoid short circuits associated with loops and wyes. No short circuits = no problem.








Sorry if you can't get your Holley to work for you. Like wiring, they are not that difficult to understand with some thought and research. I have a 650 dp on the shelf with an electric choke that works fine if you need one.


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## Cougar Rock Rail (Jan 2, 2008)

You don't have to understand DCC to wire a track to avoid short circuits associated with loops and wyes. No short circuits = no problem. 
(Sorry if you can't get your Holley to work for you. Like wiring, they are not that difficult to understand with some thought and research.) I have a 650 dp on the shelf with an electric choke that works fine if you need one. 

LOL, getting it to work isn't the problem...it works exactly how it's designed....it's just that if you pour enough fuel in, it'll make the power....just not very efficient! And like the EPL system, it's a few decades old and I've spent enough time fixing old wires in the Golden Age of DC, as Greg calls it!


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## Greg Elmassian (Jan 3, 2008)

Todd, you missed that the autoreverser also has a "circuit breaker" in the circuit as an ADDITIONAL function. 

By the way, all that is needed to implement this is an insulated track section, 2 wires to the "main line" and 2 wires to the insulated section... 

You relay hookup has to be more complex than that, more insulated sections, sensors, or whatever. 

Give this one up, you cannot compete here with relays, and other than a race car, no modern car has a carburetor and can get high efficiency and good mileage... sheesh... 

Greg 

p.s I know you are going to be "forced" to give us a diagram... ha ha


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## toddalin (Jan 4, 2008)

Posted By Greg Elmassian on 21 Jun 2011 01:37 PM 
Todd, you missed that the autoreverser also has a "circuit breaker" in the circuit as an ADDITIONAL function. 

By the way, all that is needed to implement this is an insulated track section, 2 wires to the "main line" and 2 wires to the insulated section... 

You relay hookup has to be more complex than that, more insulated sections, sensors, or whatever. 

Give this one up, you cannot compete here with relays, and other than a race car, no modern car has a carburetor and can get high efficiency and good mileage... sheesh... 

Greg 

p.s I know you are going to be "forced" to give us a diagram... ha ha 

Do you really think that wiring up a few relays is anywhere near as complicated as what is going on inside the DCC module? The only difference is that you didn't have to wire up the circuit board in the DCC module..., you paid someone to do it for you.

Personally, I prefer to avoid the short circuit in the first place rather than have a bunch of electroncs as a crutch to take care of the aftermath.

And as I said, Chevy notes that their big crate motors make 40 more HP on a carb as they do on their fuel injection. Not everyone is concerned about fuel mileage on every vehicle or they wouldn't be buying 720 hp on carb (but only 680 hp on fuel injection) crate motors. Some of us still believe in the old, simple ways that still work.


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## Greg Elmassian (Jan 3, 2008)

Never said the internal complexity was less. 

But, the EXTERNAL complexity is less. A simple box with 4 wires, 2 in and 2 out.


What kind of argument is it about the number of parts on a circuit board? 

Hooking just 4 wires and no other wiring or changes is better. The $45 solution is just better in all ways. 

The poor guy who started this thread needs advice. 

He does not need relays or pictures of carburetors. 

This IS the DCC forum. 

Greg


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## RGS K27-461 (Jan 8, 2008)

Thanks Greg & Todd, I'm a petrol head (ex-motor mechanic) from way back.......my V8 & carby days are done though....I've moved on, I'm in the electronics era, I made a decision to do DCC - half way through converting all my locos to DCC with QSI sound(now waiting for the Titan), tried battery power, not for me.
Greg the "Digital Specialties PSX-AR" that you mention - how many reverse sections does it power? I know the PM42 does up to 4 but you need to leave one for shorts. is there a manual or something i can read on how it works. 

Just want to have a better idea to make an inform decision when I buy/use the product. 

Yes i definitely like the KISS principle when it comes to trouble shooting. 2 wires in 2 wires out. 


Regards

Phil


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## Cougar Rock Rail (Jan 2, 2008)

I apologize I don't understand the electronics in this case, but I recall from a similar thread ages ago that the Massoth reverse loop module accomplishes it's task without shorts? 

Edit: this is pasted from their webpage:

The DiMAX Reverse Loop Module is a high performance unit which is able to handle digital track currents up to 15 AMPS without causing a short circuit. 
Conventional units cause short term, short circuits when the train enters the loop to trigger a change in the polarity of the track voltage. 
The new DiMAX Reverse Loop Module avoids just that. The deliberate overload of the Digital Central Station by this method does not exist anymore. The DiMAX Reverse Loop Module extends the lifespan of all components involved considerably.

The DiMAX Reverse Loop Module works with all NMRA/DCC compatible digital systems and depending on the voltage used, handles up to 15 Amps. Current consumption like this can easily be reached with multiple motored G-Scale locomotives or consists of multiple locomotives. 
The DiMAX Reverse Loop Module may be used in the regular short circuit mode as well.

The set includes 8 insulated track connectors and 4 sensing track units.


Keith


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## MrDCC (Dec 27, 2007)

Phil - 

I understand that you are a Digitrax user, but here is one case where you should abandon the "company line" and use the PSxAR! 

Each PSxAR includes a short circuit protector and a reverse module. 

The PSxAR was designed to minimize the flash of the short circuit when a loco bridges the gap between the reversing section and the mainline. This reduces pitting of the wheels and the resultant pick up of dirt. 

The PSxAR is programmable from 1.27 to 19 amps with jumpers - will need heat sinks beyond the 10 amp setting. But this is immaterial, as your Digitrax boosters won't provide enough UMPH to trip them if they are set above 10 amps. There is a 6 amp range setting that is just fine for your Digitrax boosters. 

The PSxAR has a simple 2 wires in and 2 wires out connection. You don't have to deal with trying to solder 12AWG wires to a card-edge connector designed for 20AWG or smaller wires. 

The PSxAR is designed to deal with the issues of Digitrax boosters. Use the "weak booster" settings and it will ease the load onto your booster - like feathering a clutch. The PM42 uses a relay and "dumps the clutch" onto your booster, many times forcing the booster to shut down due to the high transient load. 

The PSxAR is modern technology and reasonably priced. The PM42 is ancient technology and very expensive, especially if you value your time setting it up and wiring it. I know, I've done a bunch!


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## Greg Elmassian (Jan 3, 2008)

Keith, the Massoth unit is nice, and has the ability to run on DC, but the technique of sensing a short and quickly switching polarity has been shown to be a reliable way to accomplish the task on thousands of DCC layouts. 

I just don't want someone thinking this technique used in virtually all autoreversers is bad or unworkable. I would have a hard time claiming the Massoth technique, when looking at all the "angles" is superior. It has it's pluses and minuses. I likewise would not call it inferior. 

Regards, Greg


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## RGS K27-461 (Jan 8, 2008)

Thanks Bruce, I'll go Google PSxAR and see what I come up with, Looking at my track plan again I think I only need 2 PSxAR at the moment.


see signature below for new layout link


Regards 


Phil


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## Axel Tillmann (Jan 10, 2008)

In independent tests conducted in the German Gartenbahn Profs, the ZIMO reversing loop modules showed the fastest and most reliable switching times. I am personally using two of them in my layout for many years without a problem.


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## mbendebba (Jan 22, 2011)

Axel: 
Do you recall which units they tested and the time difference between the units? 
Mohammed


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## Greg Elmassian (Jan 3, 2008)

Phil, I have a page on this autoreverser, it has some options you can add also:

*http://www.elmassian.com/trains-mai...inmenu-204* 











Many people have used this unit, and it has performed well.

Regards, Greg


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## krs (Feb 29, 2008)

Posted By mbendebba on 22 Jun 2011 05:09 AM 
Axel: 
Do you recall which units they tested and the time difference between the units? 
Mohammed


Or even better - which issue of GBp had the article?
I wouldn't mind reading what they had to say about Auto-Reversers in general.

For my money, I prefer one that doesn't depend on a short at all to trigger it no matter how quickly it trips - one still needs a short to activate it.
I rather do a bit of extra wiring once than create a short every time the train transverses the reverse loop.


Knut


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## krs (Feb 29, 2008)

Posted By Greg Elmassian on 22 Jun 2011 08:33 AM 
Phil, I have a page on this autoreverser, it has some options you can add also:

*http://www.elmassian.com/trains-mai...inmenu-204* 

Regards, Greg 


Very informative write-up Greg.

That unit may be an excellent auto-reverser technically, but from a "product" perspective it's sadly lacking.

Not only is the 14-page product information on the web very poorly written and confusing, none of the issues you pointed out on your website have been addressed either in the product or in the documentation.

If I read that this product has been available since 2007, four years ago, I find that really unacceptable.

When reading through that 14 page product blurb quickly once, a few things struck me. 


Right at the beginning they show this connection diagram to wire the unit to handle a Wye:











Does that actually work?
Where does the power to the insulated track section come from if there are double gaps on either side?

The unit is also not fully DCC compliant in that it doesn't handle DCC address "00" and using that address will destroy it.


In itself not that big of an issue since this is not that common opf a DCC feature, some systems don't even provide that capability any more, but only mentioning this on page 13 of a 14 page description is another area where the documentation requirtes an overhaul.

Even on the first page where it warns about using the unit with DC - that warning is tucked off to the side as if it was an afterthought.


For me, the documentation gets an "F" even though the technology may deserve an "A".

Knut


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## DKRickman (Mar 25, 2008)

Posted By krs on 22 Jun 2011 12:18 PM 

Where does the power to the insulated track section come from if there are double gaps on either side? 


The reverse module powers the isolated section. The remainder of the layout is powered directly from a booster.


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## Cougar Rock Rail (Jan 2, 2008)

The unit is also not fully DCC compliant in that it doesn't handle DCC address "00" and using that address will destroy it. 
In itself not that big of an issue since this is not that common opf a DCC feature, some systems don't even provide that capability any more, but only mentioning this on page 13 of a 14 page description is another area where the documentation requirtes an overhaul. 


I think you might be surprised how often the address "0" gets used. I use it at my place at least once every open house and lots of times when friends want to run their DC engines, and on the last open house in our club with DCC it was also used. I wouldn't buy anything that couldn't handle it. 

Keith


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## krs (Feb 29, 2008)

Posted By DKRickman on 22 Jun 2011 12:44 PM 
Posted By krs on 22 Jun 2011 12:18 PM 

Where does the power to the insulated track section come from if there are double gaps on either side? 


The reverse module powers the isolated section. The remainder of the layout is powered directly from a booster. 
I think you're missing my point.

Where does the reverse module get its power from?
Shouldn't the two input leads of the reverse module be connected to a DCC power signal somewhere?


The way it is drawn, it only shows the output leads of the reverse module connected and the input lads unconnected.


Knut


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## Greg Elmassian (Jan 3, 2008)

Well Knut, you are technically correct, but if with only 4 wires, 2 input and 2 output, if the user is still confused it's a more basic problem ha ha!.. 

I never said the manual was great, I said the product was great. If I had a nickel for every crummy manual in "G" scale, I'd be a wealthy man indeed! 

Anyway, it's the most-recommended autoreverser in the US. Great price, lots of features, and works fine. I don't know of another product that can run as high amperage. The thing I cannot communicate with words is how it handles shorts and the reversing function, you would want to see it in operation. 

All I can say is that I can buy whatever autoreverser I want, this one is the one I want. If someone had one that worked well with over 10 amp capability, I would try it out. 

Regards, Greg


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## Cougar Rock Rail (Jan 2, 2008)

If someone had one that worked well with over 10 amp capability, I would try it out 

As noted above the Massoth unit can handle 15 Amps. Axel can tell us what the Zimo will handle...the only reference to it I could find showed it was 3 Amp. 

Keith


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## Greg Elmassian (Jan 3, 2008)

Ahh, in my case, I don't want any extra insulated joints and wires, I should have added that criteria. The "short detection" method works well enough for me. In the sun, heat, and expansion and contraction, insulated split jaw or hillmans are a pain, since they are not all metal.  


By the way, does anyone know if the Massoth unit has relays inside, or is all solid state. Seems to me that someone told me it "clicked" in operation.

Greg


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## krs (Feb 29, 2008)

Posted By Greg Elmassian on 22 Jun 2011 03:28 PM 
Well Knut, you are technically correct, but if with only 4 wires, 2 input and 2 output, if the user is still confused it's a more basic problem ha ha!..

Well Greg, you know and I know that there has to be a power feed somewhere, so do probably many people her on MLS, but there are just as many model railroaders who nothing or very little about electricity and have no interest in learning that aspect of the hobby.
They just follow the connection diagram provided for the product they bought and expect it to work.

And if it was only this one diagram it wouldn't be so bad.
But a number of people have destroyed their unit trying to use it with DC, they missed the little warning box tucked away to the left, the unit doesn't fir into the radio Shack box they specify as you pointed out without modifying the box, you need to buy and add your own terminal blocks which is rather strange - sort of an assembled unit but not quite, same applies for having to add heat sinks to get the full current output that's spec'd.


In fact, when I read through the instructions, I thought this was a single unit with all these various options - I didn't realize there were several different versions available until I read your web page - in the instructions everything is rolled into one.

To top it all off, this unit has been available for four years and the instructions are still a mess - by far the wirst instructions I have ever seen for any Large Scale product.
To me this sounds as if this item, not even sure I can call it a product, was developed on someone's kitchen table and is being assembled in somebody's basement.

It doesn't take much to write up some decent instructions for something as basic as a reverser even with these extra capabilities, the way it sits right now it leaves me with the bad taste in my mouth that this supplier doesn't care one bit about the product or their customers.

You even comment on your web page about some of the LEDs and what their indication might be - I didn't look at this closer but I assume you went through the instructions and came up empty.
And on another note, the LED indication chosen for a short and the reversing output active are backwards as well, people have already added simple external mods on the web to fix that.


All in all, as I already said - Technology implementation an "A", product implementation a big "F" for fail.


Only my opinion of course. 


Knut


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## krs (Feb 29, 2008)

Posted By Cougar Rock Rail on 22 Jun 2011 03:54 PM 
Axel can tell us what the Zimo will handle...the only reference to it I could find showed it was 3 Amp. 
Keith 
3 Amps - that's what I recall as well unless there is a new one on the horizon.


Knut


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## krs (Feb 29, 2008)

Posted By Greg Elmassian on 22 Jun 2011 04:03 PM 
Ahh, in my case, I don't want any extra insulated joints and wires, I should have added that criteria. The "short detection" method works well enough for me. In the sun, heat, and expansion and contraction, insulated split jaw or hillmans are a pain, since they are not all metal.

Greg,

You lost me....

Any reverser requires insulated joints no matter who makes it or the principle involved.
I know you said "extra", but does that really make a difference in practice?

Once you have one you need to manage whatever issues you run into.

Knut


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## Greg Elmassian (Jan 3, 2008)

The sentence says "EXTRA insulated joints"... yes it does, more track cuts, more places to fail... 

My autoreverser works fine, needs the minimum wiring, the minimum number of insulated joiners, is self powered, reliable, inexpensive, handles high power, programmable... 

So, more wires, more insulated joiners, more pieces of cut track, more money... nope, not attractive ... (and you have not lived until you read a manual translated from German) 

Greg


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## krs (Feb 29, 2008)

No question the PSxAR has a lot going for it on the pure technical end - it's a pity more attention wasn't paid to it on the product side and all the loose ends were tied up. 

Knut


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## toddalin (Jan 4, 2008)

Posted By Greg Elmassian on 22 Jun 2011 05:11 PM 
The sentence says "EXTRA insulated joints"... yes it does, more track cuts, more places to fail... 

My autoreverser works fine, needs the minimum wiring, the minimum number of insulated joiners, is self powered, reliable, inexpensive, handles high power, programmable... 

So, more wires, more insulated joiners, more pieces of cut track, more money... nope, not attractive ... (and you have not lived until you read a manual translated from German) 

Greg 

I gave it a bit of thought can do a short sensor with relays and no more external wires or track gaps than you are now using.









It would only require a couple polyswitches to serve as the detectors and the short would only last as long as it takes a polyswitch to blow. The polyswitch releases the relay and this sets the other relay reversing the current. When the other relay sets, the current to the polyswitch is released and the polyswitch resets itself for the next event.

It can work at any current level we would encounter in LS as there are polyswitches out past 30 amps. Simple stuff and like carbs, very powerful!


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## RGS K27-461 (Jan 8, 2008)

Thanks for all the input, I'm now looking at the PSxAR. 

Thanks Greg, I have looked at your site a few times 


*Layout is being wired only for DCC no DC. *
1 more question though, if I run a normal DC loco on the Layout using '00" address can the reverse sections remain connected to the PSxAR & just* NOT* allow the '00' train to enter any of the reverse sections or do I need to remove the input or output DCC from the PSxAR when using '00' address








All my friends in LargeScale only operate normal DC Locos, so I need to be able to use the '00' address


Regards

Phil


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## Greg Elmassian (Jan 3, 2008)

Todd, when your are trying to protect from a REAL short, not a slowly increasing overload, polyswitches are way too slow. The reset time is also a factor, since it has to physically cool... sometimes when clearing a short, it might take you a while... the polyswitch is really not a good choice here, since it can get pretty hot in a situation like this. 

Phil, I don't know the answer to your question, when I feed DC to my layout, I normally do not power the PSXAR, which handles the switchyard and part of the wye that leads to it. 

I'd address the question to the DCC Specialties people, and then, if they say it is fine, and you have a problem, you are covered. 

The other option is just disconnect the power inputs on the PSXAR, since it won't autoreverse on DC anyway. 

Regards, Greg


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## RGS K27-461 (Jan 8, 2008)

Thanks Greg, I've e-mailed DCC Specialties to get a defined answer. I was never intending to run DC through the PSxAR the Layout is being wired for DCC only. or off/disconnected for Live Steam.

Thanks again for your assistance









Phil


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## Axel Tillmann (Jan 10, 2008)

This is more an answer to the concept rather than to the "can it be done"

Running DC locos with an address (in some cases 0 - with ZIMO it is configurable for 1 other address e.g. 3,4....) is highly not advisable because it will lead to destruction of the motor. Technically you are are modifying the DC signal to have a longer positive or negative signal form leading to the effect that the motor is being tricked to drive into that direction, but never forget that you still" slap" the motor with constant alternating current. AC is used to demagnetize and that will happen potentially as well.

Most of us DCC users create a section on the layout that can be isolated to run DC guests with DC, or for a meet lay temporary some track on the grass.

I highly advise against DC operation on DCC layouts with the one sided phase elongation trick.


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## toddalin (Jan 4, 2008)

Posted By Greg Elmassian on 22 Jun 2011 08:05 PM 
Todd, when your are trying to protect from a REAL short, not a slowly increasing overload, polyswitches are way too slow. The reset time is also a factor, since it has to physically cool... sometimes when clearing a short, it might take you a while... the polyswitch is really not a good choice here, since it can get pretty hot in a situation like this. 

Regards, Greg 

While I do see "fast" polyswitches and polyfuses on the 'net, there is more than one way to skin a cat.

THIS IS FOR DCC OR FIXED TRACK VOLTAGE ONLY. Track power would require a modification to account for the variable power levels that may be seen by the relays.

Instead of polyswitches we use a couple of (ahem) relays. One leg of the power supply is wired though a NO contact. Another pole is used to direct current to the complementary relay when the power is removed from the first relay. The relay coil is in parallel with the track and matches the track voltage being used (or a resistor is used to reduce the current through the relay to an acceptable level). When the wheels cross the gap and create a short, the track relay will open as the current is skirted around it to ground. When the relay opens it removes the short and transfers power to the complementry relay reversing the current.

OLD SCHOOL RULES!


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## Greg Elmassian (Jan 3, 2008)

I haven't seen "fast" polyswitches, fast for a polyswitch maybe, but slow in real time as compared to a traditional glass fuse or an electronic circuit. 

Yes, you can do something crude with relays and no electronic "smarts", and the results are crude... what happens to a repeating short? The relay goes off like a machine gun, whereas smart electronics can have a programmable delay before re-applying power. 

Smart systems can also "test" that the short is removed with a small current, not turning the whole thing back on at full amperage. 

You cannot set the threshold of what the "sense" current is. You cannot adjust to variations in track voltage, small ones do occur when a lot of current is drawn by a big train. 

There's just no comparison, old school does not even close to ruling anything here, it's a poor substitute with much less functionality. 

You must own part of a relay company! 

If you ran DCC you would actually experience the benefits from "smart" electronics and have the same opinion as me, and the rest of the DCC community. 

You know, I often suggest your relay solutions in all the other forums, but here, it's really not appropriate as a solution. I know you must be having fun just coming back and back, but who is this helping? How is it constructive? How is it helping people less knowledgeable than yourself? 

Regards, Greg


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## krs (Feb 29, 2008)

I have to agree with Greg, relay technology is simply no longer appropriate for this application.

In addition to the points Greg made, relays are much too slow if the trigger for the AR is a short circuit.

For that type of operation the polarity reversal needs to be the fastest it can possibly be to minimuze the time of the short circuit.
Relays with contacts that can carry 10 or 12 or 15 amps have operate and release times in the millisecond range. With the older reversers that did use relays one can often see a slight hesitation as the train enters the reversed polarity section.

With solid state switches that switching time would be in the microsecond range which is easier on the wheel/rail contact and the booster/central station.


Now if the AR design is such that the polarity switch is triggered by a reed or some rail contact method *before* the train enters the reverse polarity section, in other words there never is a short going through a reverse loop, than relays would be fine technically to keep the cost low although I would still prefer a solid state switching device.


Knut


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## toddalin (Jan 4, 2008)

Posted By Greg Elmassian on 23 Jun 2011 12:33 PM 
You know, I often suggest your relay solutions in all the other forums, but here, it's really not appropriate as a solution. I know you must be having fun just coming back and back, but who is this helping? How is it constructive? How is it helping people less knowledgeable than yourself? 

Regards, Greg 

It provides a different train of thought on doing something that perhaps someone had not considered, or thought was possible. If it gets one person to "think," it accomplishes a goal.


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## Greg Elmassian (Jan 3, 2008)

I'm all for free thinking... but the components you are using are way outclassed by the requirements and needs of the system. Not a little, but WAY outclassed. 

It's simply not appropriate, no more thinking is necessary here. It's not constructive, it is not helping anyone. 

Your logic fails here because your building block is a relay with no electronic smarts. 

This would be like going to Ford and proposing they build cars with hammers and saws, because it would get them to think. 

Just makes no sense, and it's not just you and I, it's a whole group of people that might get the mistaken idea that this could be a good idea. 

That's why I keep responding to you. I'm not trying to win, I'm trying to keep you from leading people astray. 

We are talking expensive electronics in a loco, not a $3 mabuchi motor. 

Greg


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## East Broad Top (Dec 29, 2007)

Greg, with all due respect, so what if the technology is outmoded? It does the job, therefore it's a viable alternative and worthy of discussion within this thread. Tube amplifiers are outmoded technology, too, but many guitarists and bassists still swear by them (that is when they're not swearing _at_ them.) For that matter, steam locos are outmoded technology, but we still discuss how they work. 

The Massoth unit was discussed earlier on in this thread as a perfectly viable solution to the problem. It works with relays. You can hear them click as they reverse the polarity. It's more expensive than the solution you offered, but it has other advantages, such as not relying on a short to trigger the sensor. 

Later, 

K


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## Greg Elmassian (Jan 3, 2008)

No, it does *NOT *do the job, that is the point. There's a lot *MORE *than relays in the Massoth unit. 

I have explained in detail the major shortcomings of the suggestion. MAJOR. The suggestion does not address major issues that are needed in a DCC system. 

I don't tell you why a certain modeling technique is better than another. I don't tell you to build outdoor structures of water soluble material, that would be silly right? 

I don't tell you to make a smoke unit by lighting a fire right? 

This is that silly. You are an expert in that arena, and I am not.


And with all due respect, you have become the perfect example of what I have stated several times,* that less experienced people might think this is a reasonable solution in DCC. *



*It's not. *

Greg


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## toddalin (Jan 4, 2008)

Posted By Greg Elmassian on 23 Jun 2011 02:13 PM 
I'm all for free thinking... but the components you are using are way outclassed by the requirements and needs of the system. Not a little, but WAY outclassed. 

Greg 



"If it gets one person to think, it accomplishes a goal."

The thinking doesn't necessarily have to apply to this particular instance, but it may. You really don't know until you try it, and I don't expect that. Or it may "turn on the light" for someone in a somewhat similar situation.

I guess that's why I'm a Scientist and you're an Engineer. Different thought process and mentality.

"There's a lot *MORE *than relays in the Massoth unit."

And you know that I've posted a circuit that duplicates the Massoth unit (before it came out) using just relays, gaps, and diodes.


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## Greg Elmassian (Jan 3, 2008)

So you are a Scientist? Cool, I have degrees in Physics and Computer Science... I am a Scientist too... big whoopee.... it's not what is on paper, it's what you do with it. I was teaching Physics in 1972 to freshmen and juniors on college... I think I qualify. I have a patent in cellular technology... I think that qualifies.... How do you know what my thought processes and mentality are? 

Take a breath before you believe you are superior.... I've met a lot of people way smarter than me in my life, and they have never said anything insulting about being an engineer, nor that their thought processes were better or even different.... they never had to use this gambit to prove their point, they use facts and logic. 

So, you have dissected a Massoth unit and it is made of just relays, gaps and diodes? 

Well, if you even bothered to read the massoth manual you would see it can work both ways, short circuit detection, or occupancy detection. 

In any case, mentioning "cloning" the functions of the Massoth (which you really have not done) is not the range of functions we have been discussing, about "intelligent" short circuit detection, like the PSxAR, and the Zimo, and most likely the Massoth. 

Just because a Yugo and a Ferrari are cars, they are not doing the same job. 

In this case, you need to come up with: 

Short circuit detection 
controlled reapplication of power 
delayed reapplication of power 
detection of common surges vs. a real short 
fast switching (faster than a mechanical device) of power 
remote programmability 
remote configuration of thresholds of operation 

Yes you have come up with something that can switch polarity... 

You have done only very little of the "job" and it's really a worthless suggestion... If anyone thinks that they should follow your advice and use your circuit instead of a commercial autoreverser at $45 then you have indeed done the hobby and your fellow modelers a disservice. 

But, you may win the battle of words... I'm done in here.... if you want to continue to expend energy on this subject, be my guest, I'll no longer visit this thread... 

There you go, you win... 

Greg


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## toddalin (Jan 4, 2008)

Posted By Greg Elmassian on 23 Jun 2011 04:00 PM 
So you are a Scientist? Cool, I have degrees in Physics and Computer Science... I am a Scientist too... big whoopee.... it's not what is on paper, it's what you do with it. I was teaching Physics in 1972 to freshmen and juniors on college... I think I qualify. I have a patent in cellular technology... I think that qualifies.... How do you know what my thought processes and mentality are? 

Greg 



I never said a Scientist was superior to an Engineer, they just think differently as would an artist or CPA. Sounds like you have a chip on your shoulder. Nothing more to be said here.


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## RGS K27-461 (Jan 8, 2008)

Thanks everyone for your input. Tony from DCC Specialties has replied to my e-mail. Yes you can use both normal DCC and the analog address 00 with the PSxAR and NOT cause any damage.

Quote Tony: "Phil, You can do that the DC will not harm the PSXAR & the analog address will do, mimic, the same as DC" 

Regards and many thanks









Phil


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## krs (Feb 29, 2008)

Posted By RGS K27-461 on 24 Jun 2011 06:22 AM 

Quote Tony: "Phil, You can do that the DC will not harm the PSXAR & the analog address will do, mimic, the same as DC"





Was that the complete reply?

Rather strange that they warn against using the unit with either DC or address 00 in their documentation and suddenly it's not an issue.

I also know one person who damaged his unit and that was supposedly because he switched to DC power and had missed the warning on the DCC Specialties instructions.

Knut 


PS: How do I get rid of this 'garbage' at the bottom after the quote?
It didn't even show up in either my original post (before I sent it) or now when I try to edit that post.


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## Dwight Ennis (Jan 2, 2008)

The garbage shows up if you go to HTML view at the bottom of the editor. Did you by chance use MS Word to compose your reply and then paste it into the editor? I saw MS Word in the code using the HTML editor.


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## krs (Feb 29, 2008)

I just replied directly in the MLS reply box, no detour via Word or anything else. 
Maybe Phil in his post used MS Word.


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## RGS K27-461 (Jan 8, 2008)

Sorry Dennis, The garble bottom of my last post is that I cut the answers directly from my e-mail and posted. Won't do that again.









Sorry

Phil


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## SteveC (Jan 2, 2008)

The problem most likely started when Phil most likely copied his quote from Tony's eMail which most likely was received in Outlook and then pasted it into his reply. Then when you quoted his reply, this made things get worse, next you edited the quoted reply text which partially deleted some of the mso (i.e. Microsoft Office) HTML and then posted it.

As Dwight stated, the mso HTML will not display in the MLS HTML editors content area while in the Normal view mode (i.e. the editor's default mode), so the only way to see it is to switch to the HTML view mode and delete it.


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## RGS K27-461 (Jan 8, 2008)

Posted By krs on 24 Jun 2011 07:28 AM 
Posted By RGS K27-461 on 24 Jun 2011 06:22 AM 

Quote Tony: "Phil, You can do that the DC will not harm the PSXAR & the analog address will do, mimic, the same as DC"





Was that the complete reply?

Rather strange that they warn against using the unit with either DC or address 00 in their documentation and suddenly it's not an issue.

I also know one person who damaged his unit and that was supposedly because he switched to DC power and had missed the warning on the DCC Specialties instructions.

Knut 


PS: How do I get rid of this 'garbage' at the bottom after the quote?
It didn't even show up in either my original post (before I sent it) or now when I try to edit that post.


Knut, no it was the 2 short answer from 2 separate e-mails as i didn't think Tony understood my first.


1st email in full with answer.
Hi, I'm Looking at Purchasing a few PSxAR for my LargeScale Layout and I have been informed that the PSxAR cannot handle the '00' address on a DCC System. Can you Advise me if this is correct. If I run a normal DC Loco on the DCC Layout using the '00' address to run a DC Loco can the reverse sections remain connected to the PSxAR & just NOT allow the '00' address loco to enter any reverse sections or do i need to remove the input or output from the PSxAR when using '00' address. 
Tony's first reply: Phil, You can do that the DC will not Harm the PSxAR. 


I wasn't happy with the reply as I didn't mention using DC power only a DC(analog loco)

My 2nd E-mail in full to DCC Specialties - Tony.
Thanks Tony, I'm Not trying to run DC power just an analog Loco on a DCC Layout using the '00' address to run that loco. The only reason I ask is your manual for the PSxAR on page 13 says you cannot use the analog '00' address. My solution was not allow any locos DCC or analog to run through the reverse sections when using the '00' address. or my 2nd option was not to power up the PSxAR at all whilst using the analog '00' address. Sorry if I have misunderstood you. Thanks Phil.

Tony's 2nd reply: The analog address will do, mimic, the same as DC.

Those are my e-mails and Tony's replies in full

Sorry for any confusion, but I did seek clarification re their manual clearly stating that it could not handle the '00' address.

Hope this clears it up.

Regards 

Phil


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## Cougar Rock Rail (Jan 2, 2008)

Hi Phil, 

I was just reading about that PSxAR module on one of the retailer sites and it says you need to add a heat sink for anything over 10amps. It looks like the Massoth unit is around double the price but has an enclosure, can handle 15A as-is, has the option of using the short or non-short methods, and comes with all the hookup parts needed and can you know for sure it can deal with the analogue loco. Seems to me the extra $50 is worth it? 

Keith


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## krs (Feb 29, 2008)

Phil, 

I found both your email queries clear, precise and non-ambiguous. 

Can't say the same for Tony's replies. 

What does : "The analog address will do, mimic, the same as DC" mean? 

To me all it says that you can use the analogue address to run an analogue (DC only) loco because that "mimics" for the analogue address what DC power would have been for the analogue loco. 
Not really true because you will destroy a loco with a Faulhaber or coreless motor, but let's leave that aside for now. 
Neither reply addresses your key question where you specifically refer to a page in their instructions that states that the unit is not compatible with address "00". 
Actually, in the first reply Tony says that you can use DC power as well (as long as you don't run the through the reverse sections?) 

So what happens if in either situation you try to run the loco through the reverse section by mistake? 
Does the trains just stop? 
The instructions also state that connecting the DCC input to the output terminals by mistake will damage the unit. 
With DC operation you can end up connecting DC to the output terminals of the reverser if a switch is thrown wrong. 
I think a clearer and more detailed answer would really have been appropriate specifically addressing what the two warnings in the instructions are all about - no DC operation on page one and no "00" operation on page 13. 

Knut


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## krs (Feb 29, 2008)

Posted By Cougar Rock Rail on 24 Jun 2011 12:01 PM 
Hi Phil, 

I was just reading about that PSxAR module on one of the retailer sites and it says you need to add a heat sink for anything over 10amps. It looks like the Massoth unit is around double the price but has an enclosure, can handle 15A as-is, has the option of using the short or non-short methods, and comes with all the hookup parts needed and can you know for sure it can deal with the analogue loco. Seems to me the extra $50 is worth it? 

Keith 
Keith,
Check the PSxAR write up on Greg's website.

Very nicely done, covers the additional heat sinks, enclosure and other items.

Knut


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## mbendebba (Jan 22, 2011)

Posted By Cougar Rock Rail on 24 Jun 2011 12:01 PM 
Hi Phil, 

I was just reading about that PSxAR module on one of the retailer sites and it says you need to add a heat sink for anything over 10amps. It looks like the Massoth unit is around double the price but has an enclosure, can handle 15A as-is, has the option of using the short or non-short methods, and comes with all the hookup parts needed and can you know for sure it can deal with the analogue loco. Seems to me the extra $50 is worth it? 

Keith


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## mbendebba (Jan 22, 2011)

Posted By Cougar Rock Rail on 24 Jun 2011 12:01 PM 
Hi Phil, 

I was just reading about that PSxAR module on one of the retailer sites and it says you need to add a heat sink for anything over 10amps. It looks like the Massoth unit is around double the price but has an enclosure, can handle 15A as-is, has the option of using the short or non-short methods, and comes with all the hookup parts needed and can you know for sure it can deal with the analogue loco. Seems to me the extra $50 is worth it? 

Keith 
Keith: I could not agree more and I might add: it takes all the guess work out of the picture.

Mohammed
http://www.allaboutlgb.com


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## RGS K27-461 (Jan 8, 2008)

Knut,


look at this link it is 15amps. but after you read the manual you need to add a few things to minimize arcing at the wheels. Not sure how long some of the components would last outdoors. It's very damp/wet on the side of a mountain where I live.

DIMAX Reverse Loop Module. No Short Circuits!
Item-No.: 8157001 DIMAX Reverse Loop Module 


All Massoth manuals 

Regards

Phil 

http://www.massoth.com/en/produkte/8157001.en.php


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## krs (Feb 29, 2008)

Phil,

I would only use the Massoth unit if the trigger is via the sensor tracks, not via the short circuit simply because the polarity switching is done with relays and you will end up with a much longer short circuit duration than with a solid-state switch. 


But you need to consider something else.

When I look at your trackplan, one leg of the Wye is actually part of the reverse loop and the legs of the Wye are quite short. If you're running lighted cars or anything with a power pick-up I think you need some arrangement as shown in the Zimo manual with their reverse loop module so that shorting both sets of gaps on the wye don't create a problem.

Not sure how the Massoth or the PSxAR can handle that.










As to he "15 Amps", the reversing unit only has to be able to handle the maximum current of one train unless there is a fault and as far as moisture etc. is concerned, you will need to protect any electronic circuit as best you can.
I would place the module into a small builbing to give it some protection against the elements.


Knut


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## krs (Feb 29, 2008)

The Zimo MX 7/3 handles Wyes with short legs and trains that have cars with power pick ups but it's a 3 amp unit.


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## RGS K27-461 (Jan 8, 2008)

Thanks Knut, 
There is approximately 10 feet between each point at Forks Creek Wye. And approx 20 feet at the snow shed reverse loop section.


This is why i was originally looking at the Digitrax PM 42 to handle the reverse sections/short circuit. still thinking about the PSxAR though...just don't want invest in something that comes up short in what the manufacturer has stated their product will do. No pun intended









Biggest loco I've got is the Bachmann K27, waiting to install the new QSI Titan like everyone else, not sure what the current draw will be with Titan sound. I have a couple of Accucraft Geese as well with sound. don't want anything that maybe maxed out by just one loco.
I have seen the Dimax Reverse Module on evil bay for $149.00 US. it comes with everything but reading their manual, I'd need one for each of my reverse sections as I couldn't guarantee that i would only use 1 reverse section at a time. 

Regards

Phil


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## krs (Feb 29, 2008)

Phil, 

Depends what kind of trains you run to decide if the Wye needs any special treatment. 
My longest train is a 12 car RhB passenger train - each car is 2 feet plus the loco, so I'm even over the 20 feet of your reverse loop. 
But if your trains are shorter than 10 feet or there are no power pick upd other than the engine, you will be OK. 

From what I read, the PSxAR is a better unit than the PM 42 mostly because the switching is solid state and the switching is very fast; I don't really understand why address "00" should create a problem or is not supported as they put it. 
It's still a standard DCC signal but artificially made non-symmetrical to get the DC offset to drive a DC motor. 
I know some DC motors don't like to de driven that way but I never heard of a DCC reversing module that can't handle the DCC zero-stretching signal. 
Would be nice to know why that statement was made in the instructions.


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