# What DCC decoder do I need



## RCE (Sep 14, 2009)

I am STILL thinking of going to dcc What decoders do I need for motor control or for motor and sound ?
I know that QSI makes a good motor/sound decoder.

I also know that the Phonix is a good sound system. 

BUT what else do you recommend ?

I have:
1) 1 Aristo center cab diesel 

2) 2 Bachmann "annies" 

3) 4 Aristo eggliners 

For the center cab what 1. motor decoder or 2. what motor/sound decoder?

For the Annies what 1. motor decoder or 2. what motor sound decoder ?

For the eggliner what motor decoder?

Thanks for the help
Richard


----------



## Greg Elmassian (Jan 3, 2008)

For the money, the QSI is my choice of combination motor and sound decoder. 

The Phoenix sounds great, but you need to add an inexpensive motor decoder and you lose all the benefits of them in one unit, like space, cost, current consumption, but the big one is the sounds changing following the actual load on the loco, once you have heard this, you will be spoiled forever. 

For more capability, or the ability to modulate the "chuff" on a smoke unit, the Zimo MX695 is my favorite. 

I've tried everything else, and they are either not as good, or documentation is poor (or not in English), or support in the US is poor. 

I know the QSI is a "coming soon" product, I'd wait for it for your locos, unless you cannot wait or you want to do puffing smoke, and then get the Zimo. 

Regards, Greg


----------



## mbendebba (Jan 22, 2011)

You have lots of choices, I sell Massoth decoders and I consider them superior to most. You can even start with a motor decoder and add a sound decoder later. The support for Massoth decoders and Massoth products in general is second to none.
Mohammed 
http://www.allaboutlgb.com


----------



## Axel Tillmann (Jan 10, 2008)

The best decoders in the Market are undoubtly by ZIMO. What sets them apart are they feature sets as well as their unmatched driving controls.

We install into Eggliners the HO version either with or without sound. The eggliners are fun toys so our customers like fun sounds such sleigh bells as a motor noise for a Christmas eggliner or the sing flight of a bumblebee for the matching eggliner.

Larger engines need larger decoder e.g. MX695 series. 

Buying an integrated decoder is always more advantageous compared to buy a decoder and a separate sound board.

Regards
Axel


----------



## Greg Elmassian (Jan 3, 2008)

By the way, for the record, I do not sell anything, nor do I receive any compensation from anyone (although I have done some design consulting for AML and got paid with a few box cars). 

Not putting anyone down, just a calibration for my "loyalities".. 

And I did forget to mention I have used several Zimo HO decoders in smaller locos with great success. I'm also using a very small Zimo sound decoder in Z scale, and it beats the pants off the other Z scale offerings. I even was able to get support on a Sunday for a problem (my fault). That's second to none in my book. 

Regards, Greg


----------



## mbendebba (Jan 22, 2011)

Richard: Everyone has an opinion about decoders and everything else that affects your trains. Find someone you have the same loco you have, or check out youtube for the same loco, find out for your self what appeal to you most. Once you install sound in a loco you will have to live with it for a while. Sound is by no mean cheap. I would not jump in without doing my homework


----------



## Greg Elmassian (Jan 3, 2008)

Just for grins, I went to the Massoth site to read the manual on the XLS decoder. Would this be the "standard" large scale decoder? I can tell you right off that there much more configuration possible with the Zimo, unless there is a different manual that the version 2.5 on the web site. 

Maybe for some people fewer features is better, but compare with the QSI and Zimo, really no contest. Also, one thing I did not like is that I have to "register" for downloading sound files... maybe a small thing, but kind of obnoxious if you are buying a decoder that you basically have to load yourself. 

Maybe I missed something? 

It does appear that there are some very helpful and knowledgeable people on their forum, some guy named Keith ;-) 


Greg


----------



## mbendebba (Jan 22, 2011)

You appear to be misinformed. The XLS come with your choice of loco sound files uploaded to the decoder. Should you decide one day to load a different loco sound file to onto that decoder, you can get any other loco soundfiles free of charge (except for registration, a securitymeasure) anytime you wish to do, I would call obnoxious unless I have an ax to grind


----------



## East Broad Top (Dec 29, 2007)

Personally, I make my choices based on what sounds I want. The basic motor-control functions of the various decoders are (generally speaking) fairly similar. The noticeable difference for me is in the sounds. What particular chuff, whistle, bell, etc. do I want with each individual loco? Find a sound set you want and go from there. They're mostly all online, so you can listen from the comfort of your computer. Note: the sounds coming from your computer speakers will be slightly different from what ultimately comes from your loco, but it's generally close enough to get a good sense of whether you like the tone of the whistle, bell, diesel motor, etc. 

If you like a QSI sound for a given loco, go with that. (Or, right now, wait until the end of August when they're supposed to be available again, _then_ go with that.) If a Phoenix soundset strikes your fancy, go with that and a separate motor control decoder. You can program a lot of variation into the chuff cadence of a Phoenix based on rates of acceleration, deceleration, and speed it gets from the decoder. I've got both QSI and Phoenix, and both perform very similarly in response to changes in speed and load. _How_ they do the "calculations" differs, but the end result on both is very realistic. Because I run battery R/C, and the Zimo and Massoth systems don't (yet) work in that environment, I can't speak to their operations beyond what I've heard online, but those who use them generally love them. 

Don't overlook the Soundtraxx Tsunami motor/sound decoders, ether, especially for the eggliners. Some folks have had good luck with them in large scale locomotives where (a) there's not a lot of current draw to worry about and (b) you don't desire boom-box-shattering volume levels. Just check the specs to make sure you're not going to over-voltage them with your track voltage. 

Later, 

K


----------



## Axel Tillmann (Jan 10, 2008)

Most decoders nowadays are field upgradeable meaning microcodes and sounds can be customized by the customer.

However, each uses a different technology of loader/programmer therefore if one gets into the hobby and can justify the expense wants to consider such a loader module in order to get even more flexibility or change sounds o. The Cly or do even your own sounds.

But you probably don't want to end up with many loader modules, hence it is important to to choose the most flexible decoder.

I have in. Several hundred installations never encountered a single problem that I couldn't solve with ZIMO.

I choose ZIMO for my own hobby long before I got into the business.

Regards
Axel


----------



## Greg Elmassian (Jan 3, 2008)

Kevin, you do need to couch your "tastes" so that people realize what YOU like, which is the basics, and good sound. You DON'T run DCC and you don't use all the capabilities. You have mentioned over and over about why the QSI does not have reed switch inputs and automated whistle from a start. This is NOT mainstream DCC use.

That's fine, there is no affront intended, but in DCC many people go there for the sophisticated functions and capabilities. 

(otherwise all of us would be running the Revolution $50 sound add on!! or Dallee, etc.). 

And PLEASE, do NOT recommend Soundtraxx Tsunami decoders for large scale DCC... you need to read my site on this... basically their voltage limits are UNACCEPTABLE for large scale dcc... (I think you must be thinking of running them on DC or you have forgotten all the irate uses of the one in the Bachmann shays)

(I'd like to meet the people in large scale DCC who have had good experiences with them... seriously... ) 

PLEASE, let's not recommend poor choices to new people.... (and make this thread like the "use relays for a DCC autoreverser" thread... 

Greg


----------



## krs (Feb 29, 2008)

..........and make this thread like the "use relays for a DCC autoreverser" thread... 

Ha, ha, ha............. 

I was going to suggest a manual DPDT toggle switch there instead of relays, but I bit my tongue.


----------



## Greg Elmassian (Jan 3, 2008)

I hope not Knut! Funny is funny, but that thread was absurd. Maybe I should build a command station and hand held throttle from relays and diodes... 

I have fought with the HO Tsunami decoders and they are, for use in G scale... crap... they overheat easily, even putting a 3.5 volt dropping array in front of one still made it overvoltage, they do NOT meet their specifications on amperage (overheated on a .7 amp motor), and they are overly sensitive to power interruptions (sound reset all the time)... I swapped them out with a Zimo and all my problems went away, because the HO Zimo decoders are designed for track voltages up to what is commonly used in G scale. 

(I tried them in an AML Casey Jr. and a Berlyn Casey Jones rail truck, I really worked at making the POS work) 

Regards, Greg


----------



## East Broad Top (Dec 29, 2007)

Kevin, you do need to couch your "tastes" so that people realize what YOU like, which is the basics, and good sound. 

I believe, Greg, that's what I did when I started my post with "Personally, I make my choices based on what sounds I want." But in case it wasn't clear enough for the reader, yes, I put sound over control as a driving force. I don't need much in the way of fancy speed curves, consisting, or speed matching because that's not needed for my railroad. If that's a priority, then the selection criteria shift to motor control as being the dominant consideration. Alas, Richard didn't really speak to what his priorities were, so I answered based solely on how I would make _my_ choice. 

And PLEASE, do NOT recommend Soundtraxx Tsunami decoders for large scale DCC... 
As for the Tsunami decoders, I'll continue to suggest them _with the provisos stated in my previous post._ In low-current applications where the track voltage is well within the tolerances of the decoder (not reduced via dropping resistors, regulators, etc.) it's been demonstrated to work. *If* your system falls within those tolerances, *then* they're a viable alternative. True, _many large scale systems do not,_ but that's not to say they _all_ don't--especially those who run narrow gauge and don't need the high voltages for high speeds that standard-gauge modelers might prefer to run at. I certainly wouldn't need it for mine if I were to power the track to my railroad. I run 14.8 volts worth of batteries in my locos, and don't have a single max speed CV set above 70% on any of my locos. If I were track-powered DCC, I'd use my 13.8 volt power supply that I use to power my workshop shelf RR. If I needed to power a small loco or speeder, the Tsunamis would be perfectly viable. I have no reason to doubt your negative experiences with the Tsunamis, and thank you for providing them so readers can get all perspectives. That doesn't mean that other modelers haven't had better results with them. Who, you ask? Do as I did, and search Google. They're out there. And yes, your site came up in one of my searches when I was researching them, which is part of my placing the caveats on its use that I do; *low voltage, low current, low volume. * 

You DON'T run DCC and you don't use all the capabilities. 
It's funny how often you say that, because it shows you don't understand how I run my railroad. I don't know where the disconnect lies, and I'm sure it could easily be remedied by coming over if you're ever in Denver and me handing you one of my controllers. (Hint: you'll be very familiar with the keypad.) 

I _do_ run DCC, and I use a great number of its features--just not in the "traditional" sense with power/control running through the track, and just not the exact same features you do. I use on-board batteries as a power source instead of a stationary power supply, and I transmit the commands via a wireless controller directly to a receiver in the locomotive instead of a stationary base station that then sends signals over the rails to the appropriate decoders. And I--like many DCC users--use only those features I find relevant for my particular needs. There are two rather large HO clubs out here that use NCE on their railroads as you do on yours. They don't even scratch the surface as to what their systems are capable of. One does a fair amount of consisting, but that's largely the extent of their interests beyond making sure the train moves when and where they tell it. Sound is all pretty much factory defaults. The other went to DCC simply because they got tired of complicated block wiring. Much of their stuff they just program with a unique ID number and they're done with it. Compared to them, I'm a veritable power user. I want to individually control numerous sounds and lights, and have very specific control over how those functions work and how they interact with the speed of the locomotive. I use different combinations of products based on my choice of sound, space available for the installation, and money I want to put into the system. (I'm also not limited by "needing" to use DCC-protocol controllers, either, but that's tangential.) So, yes, I'm a DCC user--no different than you, the guys in the HO clubs I mentioned, or any other model railroader who controls his trains via command packets that conform to the NMRA's DCC protocol, no matter what their needs are. The difference between all of us lies solely in the level to which we implement the technology to meet our specific individual goals. 

I think you and I are a lot closer in terms of what--specifically--we look for than you realize. We have different goals because we have vastly different operating environments. I'm slow narrow gauge, and battery power. You're fast standard gauge, and track power. That's about as diametrically opposed in terms of modeling tastes as you can get in model railroading. Yet we both gravitate towards DCC because it gives us the flexibility to control our trains to our satisfaction. You and I can buy the same decoder, and based solely on how we program it, get it to do precisely what we want within our disparate modeling tastes. You place a higher premium on motor control than I do because your railroad needs it for speed matching and consisting MU diesel lash-ups, and you are willing to sacrifice a bit on sounds to get that. (Though QSI doesn't have anything to be ashamed of in the sound department, either.) I want realistic chuffs and whistles for switching a rural narrow gauge railroad with a single locomotive, and find pretty much all decoders to have adequate motor control for my needs there. So I choose a sound system that matches my locomotive and its individual needs and build out from there. Two paths to the same destination. 

Later, 

K


----------



## krs (Feb 29, 2008)

Posted By Greg Elmassian on 25 Jun 2011 07:05 PM 

I have fought with the HO Tsunami decoders and they are, for use in G scale... crap... they overheat easily, even putting a 3.5 volt dropping array in front of one still made it overvoltage, they do NOT meet their specifications on amperage (overheated on a .7 amp motor), and they are overly sensitive to power interruptions (sound reset all the time)... I swapped them out with a Zimo and all my problems went away, because the HO Zimo decoders are designed for track voltages up to what is commonly used in G scale.


Greg,

Do you know what the maximum voltage rating is for the Tsunami H0 decoder?
If it meets the NMRA spec it should be 27 olts or better.

I couldn't find any spec for that on their website but on the very first page it says:

The Tsunami™ sound system is SoundTraxx’s high-performance, onboard locomotive sound system. Tsunami Digital Sound Decoders integrate a full-featured sound system, Hyperlight lighting effects, a motor controller and a DCC decoder into a single, integrated package and* is compatible with the NMRA DCC standards and Recommended Practices.* 
Well, seems NMRA has lost all interest in DCC, these decoders don't seem to be NMRA DCC compatible but nobody there cares that the advertise just the opposite.


Knut


----------



## krs (Feb 29, 2008)

Posted By East Broad Top on 26 Jun 2011 02:41 AM 
As for the Tsunami decoders, I'll continue to suggest them _with the provisos stated in my previous post._ In low-current applications where the track voltage is well within the tolerances of the decoder (not reduced via dropping resistors, regulators, etc.) it's been demonstrated to work.
Kevin,

What are the voltage tolerances of these decoders?
I couldn't find anything on the Tsunami website.


These decoders are advertised as NMRA compliant - that means that they can handle a DCC track voltage of 27 volts minimum.
Seems that is not even remotely the case - talk about false advertising!


Knut


----------



## East Broad Top (Dec 29, 2007)

I thought I had read on their site at one point that they topped out at 21 volts, comparable to the Tsunamis that were installed in the B'mann 3-truck Shay. I can't find that reference anywhere now, either, so I don't know if I read that on Tsunami's site or on Greg's or if it was somewhere else where I got that. The only reference to maximum voltages on their web site is here. It _does_ state a maximum of 27 volts, so if they're giving overvoltage errors at 21, then--yeah--that's problematic for those going by published specs--in which case I'd amend my recommendation to make sure if you're going to use the Tsunami, just make sure you use it in low voltage application (


----------



## krs (Feb 29, 2008)

Posted By East Broad Top on 26 Jun 2011 09:33 AM 
The only reference to maximum voltages on their web site is here. It _does_ state a maximum of 27 volts, so if they're giving overvoltage errors at 21, then--yeah--that's problematic for those going by published specs--in which case I'd amend my recommendation to make sure if you're going to use the Tsunami, just make sure you use it in low voltage application (


----------



## East Broad Top (Dec 29, 2007)

The typical DCC track voltage for H0 is 14 volts; I wouldn't be surprised if that is all the Tsunami can handle. 
Their instruction manuals are equally vague. They do recommend that incandescent bulbs from 12 - 16 volts can safely be used with the unit. From that, I would infer that either of two things... (a) the unit has some level of voltage regulation on the lighting outputs bring it down to 16 volts from whatever maximum voltage is applied to the track, or (b) there's no voltage regulation and the unit has a top end voltage just north of 16 volts. Don't know. 

As for recommending it, I think you have to look at the situations where it has been successful compared to where it's been a failure. Small scalers seem to be fairly pleased with its performance at typical HO track voltages (12 - 18 volts), based on what I've read and heard at shows from users. From what I've read online, people have been successful in using it in large scale up to around 20 volts, but that seems to be the upper limit. Certainly Greg's luck with them north of that has been dismal at best. If the book is unreliable, you can only go by practical experience. You have to figure the decoder doesn't know or care how far apart the wheels are, so if people are having good luck with it in one arena, so long as you play by the same rules, you can expect similar results. 

Later, 

K


----------



## Road Foreman (Jan 2, 2008)

Rich, 

Per your drawing yesterday.. I would go with Digitrax's SDH164D decoder for the Eggliners.. For more sound change the speakers to larger 8 ohm ones.. If you do not want sound you can use the DH123D decoder.. For the Aristo center cab I would use the DH465 & add the soundbug SFX004 decoder.. Again if you want more sound go to a larger speaker.. Check the "annies" for current draw & if the SDH164D decoders will work I would go with therm.. I have found that ACCU-LITES, Inc have very good prices for the decoders.. When you start installing the decoders pay close attention to the wiring so the engines will run forward when you run DC.. Hope this helps.. 

BulletBob


----------



## East Broad Top (Dec 29, 2007)

Greg, I didn't see your request until this morning, so I honored it as soon as I saw it. (Though I left all your posts up to yours of last night.) I also deleted my rebuttal. No one's suggesting you're not trying to help the beginner, and we're all appreciative for your work in that regard. 

Here's the thing. I've read through your web site, and can find no evidence to support the position that you _need_ 24 volts to operate a large scale DCC railroad. To my reading of it, you only need that voltage if the speed at which you wish to run your trains requires it. I'm not suggesting that you're wrong, but I'm trying to understand where I may be. Is 18 volts sufficient to operate a large scale DCC railroad? If not, why not? 

Neither the analog track power or battery power camps have any kind of "mandatory voltage" requirement. You set your maximum voltage based on your individual operational requirements. I've gone 35 years in this hobby and never needed a power supply that fed more than 16 volts. I run narrow gauge, and prototype narrow gauge trains don't run very fast. What is it that sets large scale DCC apart that you feel it imperative to have 24 volts? Help me understand that, and I'll understand why the Tsunami is unsuitable for large scale DCC at all levels. But failing that, I can see no reason why if your operating environment is within the realm of reliability for the Tsunami (or any other) decoder, that it would be bad to recommend it so long as it's only used within those strict confines. 

Later, 

K 

PS - I thought about jokingly recommending the MRC decoders you mentioned just to see if I could get your blood pressure to spike, but thought better of it. Yours and my experiences with them are the same. I've got two. One went poof. (Naturally, the steam one.)


----------



## benshell (Oct 1, 2008)

My advice, without much personal experience to back it up but lots of observation, is to setup your layout to run any type of locomotive if possible. It's really nice to host run days and let people run anything. I understand there are battery/live steam only layouts, but if you're going to all the trouble of hooking up power, and even DCC, then it makes sense to have a voltage and power capability that will let anyone run their DCC engines. I don't know about narrow gauge, but I do know from personal experiences that USA Trains diesels run really slow on 15 volts. I'd say you want at least 18 volts, more preferably. Of course if you just want to run your own narrow gauge equipment and not host open run days then you can do whatever you want.


----------



## krs (Feb 29, 2008)

Kevin, 

Re the 24 volt requirement for Large Scale, let me throw out a few facts: 

1. Initially LGB was the only kid on the block for many years, even though they started with a 14 volt power pack back in 1968 they quickly raised their power pack voltage to 24 volts and that became the de facto standard for Large Scale in analogue operation and has been for years. 
Sure, you can run some locos on 16 volts and they run fine, just slower. that's no different than running H0 locos at 8 volts when their standard DC power pack voltage is 12 VDC - but thatdoesn't make 8 volt the H0 standard. 

2. For DCC, NMRA specifically shows a maximum track voltage of 22 volts DCC, it should really have been 26 volts DCC since one "looses" typically two volts through the decoder but NMRA never took Large Scale seriously so that perhaps explains why they didn't chose what would have been the correct maximum DCC voltage for Large Scale. 
For H0 DCC the maximum voltage is correctly specified at 14 volts, two volts higher than the maximum DC voltage the H0 motors like to see. 

3. Any NMRA compliant DCC decoder for H0 scale and up must tolerate a DCC voltage of 27 volts. That is specified in NMRA as well. The Tsunami apparently doesn't come anywhere close to that. 
I sent a question about that to the manufacturer on Sunday but do not have a reply yet as to what maximum voltage a Tsunami decoder can tolerate. 
At this point you can't assume those decoders can be used at any voltage higher than 14 volts which is the H0 DCC spec and even for that voltage there is no guarantee. 

So much to the 24 volt requirement for Large Scale. 

As to the Tsunami decoder, I don't understand why anyone would recommend it for Large Scale at all. 
The decoder is clearly designed for H0. there were two Tsunami Large Scale decoders that were announced but I haven't seen hide nor hair of them. 
This is a Large Scale forum and web site. the Tsunami decoders shouldn't even be discussed here other than to state that they are not suitable for Large Scale - simple as that. 

Knut 

PS: Oh battery.
Different kettle of fish.
For one, with battery operation the power is on board (obviously) so you don't get any losses transmitting the power to the motor, you don't worry about the delayed start circuit built into many LGB engines and you are constrained by the number of cells (= voltage) that you can install in the locomotive.


----------



## East Broad Top (Dec 29, 2007)

Ben, good point about accommodating others' locos, which really become an extension of your own roster if that's an important part of your design consideration. It's not unlike planning your railroad's curves and clearances for future purchases. I don't think that rises to the level of "requirement," but perhaps a very good rule of thumb similar to 5' radius curves being a good minimum radius. 

Knut, I've not noticed there to be a de facto standard for analog track voltage. Large scale power supplies I've seen, used, reviewed, etc. run the gamut from 16 to 30+ volts. The higher-end ones gravitate towards the upper end of the spectrum (24 - 30 volts) but there were some good mid-range power supplies made for a while that output in the 18 - 20 volt range as well. Of course, the starter set supplies, well... I think if there's a de facto "24 volt standard" out there, it's for the motors, not the power supplies. Without having specs in front of me, I think most large scale locos have motors rated at between 19 - 24 volts. 

As to the Tsunami decoder, I don't understand why anyone would recommend it for Large Scale at all ... - simple as that. 
I think the confusion stems from the fact that I tend to think outside the box; always looking for alternatives. As a general purpose large scale decoder, I'd never recommend it, either. What I saw was a very specific set of circumstances--in this case two Eggliners which draw very little current, well within the operating range of HO, S, and O-scale decoders--and a fairly inexpensive motor/sound decoder option that would work so long as the track voltage was suitable. I had no idea the tempest that would open up merely by suggesting that large scale DCC could be operated at voltages lower than 24 volts. 

But if 24 volts is the "standard" and no one wants to even consider alternatives, then yes--the Tsunami is unsuitable for large scale. If/when you're willing to look at alternatives to the "standard" way of doing things, a world of possibilities can open up. 

Later, 

K


----------



## Road Foreman (Jan 2, 2008)

Knut, 

The NMRA had a very good reason to go with 22 volts.. They looked @ the NEC & found that 50 volts is the max for low voltage.. They wanted to keep the voltage below 50 volts across a gap between 2 power district boosters.. Hope this helps.. 

BulletBob


----------



## Cougar Rock Rail (Jan 2, 2008)

Kevin there's nothing wrong with thinking outside the box, and I know lots of guys who run HO decoders in their small G locos--just use one that can handle the voltage, such as Zimo, which is probably triple the quality and features for the same price. 

Keith


----------



## RCE (Sep 14, 2009)

I probably didn't give enough information in my first post 
I have a small ( 75' dog bone )








I will be running NO MORE than two consists at a time probably only one. 
This is what I will be using IF I go DCC








I talked to Bob on Sunday (thanks Bob) and gave me the answer I asked. 
I will NOT be running high speed trains. I don't need a lot of extra stuff that the higher priced decoders offer just motor control, and ok sound ( ring the bell, sound the horn and motor sounds) on the engines I put sound in. 
If you have any suggestions on what I can use with MY engines I would like to here them. 
Thank you all that have responded so far 
Richard


----------



## Cougar Rock Rail (Jan 2, 2008)

Richard are you likely to take your engines to someone elses' DCC layout? Similarly, are you likely to want to have guest DCC engines over? 

Keith


----------



## TonyWalsham (Jan 2, 2008)

Posted By krs on 28 Jun 2011 09:43 AM 
Kevin, 

Re the 24 volt requirement for Large Scale, let me throw out a few facts: 

1. Initially LGB was the only kid on the block for many years, even though they started with a 14 volt power pack back in 1968 they quickly raised their power pack voltage to 24 volts and that became the de facto standard for Large Scale in analogue operation and has been for years. 
Sure, you can run some locos on 16 volts and they run fine, just slower. that's no different than running H0 locos at 8 volts when their standard DC power pack voltage is 12 VDC - but thatdoesn't make 8 volt the H0 standard. 

Knut 

PS: Oh battery.
Different kettle of fish.
For one, with battery operation the power is on board (obviously) so you don't get any losses transmitting the power to the motor, you don't worry about the delayed start circuit built into many LGB engines and you are constrained by the number of cells (= voltage) that you can install in the locomotive.




Sure the LGB locos required 24 volts for the motor to see an 18 volt maximum.
LGB did that so the first 6 volts was used to keep the lights, sound and smoke units operating when the loco was stationary.
The motors themselves saw only a maximum of 18 volts.
As to battery power that *you* raise.
To do what you say the loco has to be rewired by separating the motors from the other internal LGB wiring.
Then the problem of having the lighting etc powered and reversible when stationary crops up. There are ways around that, but, leaving the LGB wiring alone and using 24 volt batteries is the simplest method.


----------



## RCE (Sep 14, 2009)

Keith 
I doubt if I will ever take my trains elsewhere. If someone brings over any DCC engines they will be able to run on the layout. 
With the tight curves I have no large engines will be able to run here anyway. 
I will be able to run DC or DCC on my layout with to DPDT switch that is in the diagram in my last post. 

Richard


----------



## krs (Feb 29, 2008)

Posted By East Broad Top on 28 Jun 2011 01:20 PM 
But if 24 volts is the "standard" and no one wants to even consider alternatives, then yes--the Tsunami is unsuitable for large scale. If/when you're willing to look at alternatives to the "standard" way of doing things, a world of possibilities can open up. 
Later, 

K

Thinking "outside the box" is of course great and should be done all the time.
And if the Tsunami decoders met their own specs they would be usable for certain Large Scale engines and we wouldn't have this discussion.


Trouble is they don't meet the 27 volt spec that's specified and at this point, there is no indication what the maximum voltage is they are *designed* to tolerate - that's the key point, not what people experience in practice.


Knut


----------



## krs (Feb 29, 2008)

Posted By Road Foreman on 28 Jun 2011 01:24 PM 
Knut, 

The NMRA had a very good reason to go with 22 volts.. They looked @ the NEC & found that 50 volts is the max for low voltage.. They wanted to keep the voltage below 50 volts across a gap between 2 power district boosters.. Hope this helps.. 

BulletBob 
I have heard that before but it doesn't make any sense - some one just fabricated this.

To start with, even if I ran two DCC boosters at 24 volts, the nominal voltage across a gap in the power district would still be less than this magical 50 volts (and any voltage spikes that would add up to more would also add uo to more with 22 VDCC.


And secondly, there is no NEC maximum low voltage standard of 50 volts DC, it just doesn't exist.

Someone made that up. If you check ino it you will find:


The United States 2005 National Electrical Code (NEC) does not specifically define *low voltage*. Article 490.2 only defines "high voltage" as more than 600 volts. Nevertheless the NFPA 79 article 6.4.1.1 defines PELV as nominal voltage of 30 Vrms or 60 Vdc ripple free for dry locations and 6 Vrms or 15 Vdc in all other cases. UL 508A article 43.1.2 is more stringent and uses those values as maximum the same way as NEC 2008.


----------



## krs (Feb 29, 2008)

Posted By TonyWalsham on 28 Jun 2011 03:33 PM 
Sure the LGB locos required 24 volts for the motor to see an 18 volt maximum
LGB did that so the first 6 volts was used to keep the lights, sound and smoke units operating when the loco was stationary.
The motors themselves saw only a maximum of 18 volts.

That is only true for some of the LGB locos, not nearly all of them.
And the 24 volts was not chosen because of that feature either. 

The feature btw was introduced back in 1983 to allow simultaneous shunting with a second loco on the same loop, then with the RhB electric locos to operate the pantographs up and down before the loco started to move. Light, sound and smoke running off 5 volts came later. 


Besides that, certain USA Trains locos won't run at prototypical speeds either unless the DCC voltage is set to at least 24 volts.

It's not a specific LGB requirement. 


Knut


----------



## East Broad Top (Dec 29, 2007)

If I'm reading your diagram correctly, you're using the DPDT switch to toggle between the Airwire G2's DCC output (to run DCC-equipped locos), and traditional DC via the Airwire's motor control output terminals, and powering everything from the MRC power supply. Interesting way to do business, and gives you wireless control to boot. The G2's DCC outputs are rated at 3 amps, so that should be good for two of your locos without too much issue. 

One thing jumps out at me, though. The MRC 6200... It's got a variable DC output and a fixed AC output. The G2 won't like the AC output one iota, and if the variable output is not filtered, it's not gonna like that too much, either. (Anyone know if it's filtered? I can't remember.) Also, each output is only around 35 watts total, so if what you're running is drawing 3 amps, your voltage drops to around 11 volts or so. I'd look for a better power supply to run the G2--something regulated. The G2 can handle up to 24 volts maximum. With all the talk about maximums and stuff like that, and given your particular needs, I'd probably go for something in the 15 to 18 volt range. Much more speed than that and your trains will be rolling off your curves anyway. 

I'll leave it to others to recommend particular decoders.  I've led enough dust-ups for one thread. 

Later, 

K


----------



## SteveC (Jan 2, 2008)

Knut

I wouldn't say that your reference to a Wikipedia article is the best place to start. I think the following might be better, especially the part referencing atricle 725, in particular the class 2 & 3 circuits.

Defining Low Voltage Circuits[/b]

Additionally, I'm not putting forward the above as anything other than a starting point, if you wish to review other areas of the U.S. NEC that cover other low power circuits you might wish to consult the respective sections listed below.


ARTICLE 411 - Lighting Systems Operating at 30 Volts or less
ARTICLE 640 - Audio Signal Processing, Amplification, and Reproduction Equipment
ARTICLE 645 - Information Technology Equipment
ARTICLE 720 - Circuits and Equipment Operating at Less than 50 Volts
ARTICLE 725 - Class 1, Class 2, and Class 3 Remote-Control, Signaling, and Power-Limited Circuits
ARTICLE 760 - Fire Alarm Systems
ARTICLE 770 - Optical Fiber Cables and Raceways
ARTICLE 800 - Communications Circuits
ARTICLE 810 - Radio and Television Equipment
ARTICLE 820 - Community Antenna Television and Radio Distribution Systems
ARTICLE 830 - Network-Powered Broadband Communications Systems


----------



## RCE (Sep 14, 2009)

Kevin 
Right now I'm using the MRC 6200 to power an Aristocraft track side TE with the dc power turned up to 18.5 v. 
In the past I would run the center cab and 1 annie on the same track using the 6200 for power without the TE. 
If I need to I will switch the mode to the HO side it will put out 14 volt which will be enough voltage I think. 
I will be putting in a 3 amp fuse on the output of the DPDT switch. 
I think the 6200 will work just fine for me, if not I will look for a better power supply. 
Richard


----------



## krs (Feb 29, 2008)

Steve,

I just picked the quote from the Wiki because it was handy.

I spent 8 years as a design engineer in telecommunications including the power side of things.
There were two basic power supply voltages used - 24 VDC and 48 VDC. 
Equipment using 24 VDC supplies was used in locations where the public had ready access to the equipment - the voltage range was 20 to 28 VDC to stay below the 30 volt maximum.

48 VDC nominal is used in Central Offices not accessible to the general public, but the maximum for those supplies was 52 VDC.
Nothing about 50 VDC maximum. 


Very nice reference you posted but I still see nothing about a 50 VDC maximum limit anywhere in Article 725 that you mention:










And even if there were a 50 VDC limit, 2 times 24 volts is still less than 50 volts, there would need to be a maximum spec of 45 VDC for 22 volts times 2 (vs 24 Volts x 2) to make any sense.


Knut

PS: I flipped through all the pages in the link you posted, only 50 volts I see anywhere is about 50 volts AC and grounding.


----------



## East Broad Top (Dec 29, 2007)

Cool. If it's proven itself worthy, then no reason to abandon it. 

Later, 

K


----------



## krs (Feb 29, 2008)

How long does it typically take Soundtraxx support to reply to an email query?

On their website they suggest only a day or two.

I sent them a query on June 26th asking what the maximum track voltage is that the decoder can handle and have had no response whatsoever - not even "We'll check into that and will get back to you"

Knut


----------

