Date   
Re: Wiring

Gregory Latiak
 

You could supply power to the track with a couple of alligator clips if you wanted to test sections. As for permanent wring, DC and DCC have the same issues of polarity. And if you intend to use a PM42 for power districting, a pair of barrier strips would substitute for the output side. And the distribution of power within the district if you intended to do occupancy detection can similarly be implemented. What I did when building my 7x10 two deck layout. The difference between the two is that DC voltage varies and DCC does not. Instead, signals are sent out to tell addressable devices to take more or less power.

greg latiak

Wiring For DCC Website Update

wirefordcc
 

I have made two updates to my website.


#1:  DCC for Beginners: Do an Incremental Installation


#2:  Update on the track wiring buzzer in this post Radio Shack world and electronic devices that may go across your track like Frog Juicers and auto reversing controllers.


Allan Gartner

Wiring For DCC

Wiring LED's in a DCC converted Atlas C-424

pacific.cascade.ry@...
 


I am currently converting an Atlas Alco C-424 to DCC and have run into a problem with converting the cab and rear light systems into LED's. At my Pacific Cascade Railway web site, you can see the two long plastic light tubes used in the factory setup with one light bulb for both. Since the Soundtraxx MC2 board has separate light controls I want to incorporate two LED's, but where and how to add them. Any suggestions are welcome and will be considered. Thanks.

Capt.Brigg Franklin CEO

www.pacificcascaderailway.com in HO gauge

Vancouver, WA, USA



Re: Wiring LED's in a DCC converted Atlas C-424

Paul O
 

Cpt. Brigg, my suggestion would be to cut the light tubes somewhere about the middle of what appears to be two mounting points into the weight blocks.

Discard the inner pieces and cement the LEDs to ends of the cut tubes.

 

Paul O

 

Sent: Monday, May 29, 2017 7:50 PM
I am currently converting an Atlas Alco C-424 to DCC and have run into a problem with converting the cab and rear light systems into LED's. At my Pacific Cascade Railway web site, you can see the two long plastic light tubes used in the factory setup with one light bulb for both. Since the Soundtraxx MC2 board has separate light controls I want to incorporate two LED's, but where and how to add them. Any suggestions are welcome and will be considered. Thanks.

Capt.Brigg Franklin CEO

www.pacificcascaderailway.com in HO gauge

Vancouver, WA, USA

Re: Wiring LED's in a DCC converted Atlas C-424

Craig Zeni
 

I pretty much concur; I would look at fixing the light guides to the shell, cutting them to the 'outside' of the guides that hold the light guide to the shell. Glue LED to end of light guide and heat shrink tube the assembly to keep stray light in place.

Craig Zeni
Cary NC

On May 30, 2017, at 12:32 AM, 'Paul O' @Paul78 [WiringForDCC] wrote:



Cpt. Brigg, my suggestion would be to cut the light tubes somewhere about the middle of what appears to be two mounting points into the weight blocks.
Discard the inner pieces and cement the LEDs to ends of the cut tubes.

Paul O

Sent: Monday, May 29, 2017 7:50 PM
I am currently converting an Atlas Alco C-424 to DCC and have run into a problem with converting the cab and rear light systems into LED's. At my Pacific Cascade Railway web site, you can see the two long plastic light tubes used in the factory setup with one light bulb for both. Since the Soundtraxx MC2 board has separate light controls I want to incorporate two LED's, but where and how to add them. Any suggestions are welcome and will be considered. Thanks.
Capt.Brigg Franklin CEO

www.pacificcascaderailway.com in HO gauge

Vancouver, WA, USA



Re: Wiring LED's in a DCC converted Atlas C-424

pacific.cascade.ry@...
 

My concern is that if I cut the ends of the light tubes it will rough the ends up and the LED light will not enter the tubes clearly. How can your polish the light tube ends to make them clear again?

Capt. Brigg Franklin CEO
www.pacificcascaderailway.com
Route of the Northern star

Re: Wiring LED's in a DCC converted Atlas C-424

David Klemm
 

The easiest way to 'polish the end' is to use plastic cement to melt the end clear.  It is what I do and works like a charm.


David




From: WiringForDCC@... on behalf of pacific.cascade.ry@... [WiringForDCC]
Sent: Tuesday, May 30, 2017 1:58 PM
To: WiringForDCC@...
Subject: RE: [WiringForDCC] Wiring LED's in a DCC converted Atlas C-424
 
 

My concern is that if I cut the ends of the light tubes it will rough the ends up and the LED light will not enter the tubes clearly. How can your polish the light tube ends to make them clear again?

Capt. Brigg Franklin CEO
www.pacificcascaderailway.com

www.pacificcascaderailway.com
I finally sold my Digitrax system for a very reasonable price and purchased a new NCE system, including a Power Cab, SB5 command/booster and Cab 06r for radio control.


Route of the Northern star

Re: Wiring LED's in a DCC converted Atlas C-424

Craig Zeni
 

On May 30, 2017, at 2:58 PM, pacific.cascade.ry@... [WiringForDCC] wrote:



My concern is that if I cut the ends of the light tubes it will rough the ends up and the LED light will not enter the tubes clearly. How can your polish the light tube ends to make them clear again?
I believe you'll find that the rough surface has minimal effect on the light quality; that's been my experience anyway. Your other option (which I've also done) is to put the two LEDs between the existing light guides, over the decoder. Separate them with a piece of something opaque. A side benefit is that one doesn't tie the lights to the shell.

Craig Zeni
Cary NC

Re: Wiring LED's in a DCC converted Atlas C-424

Blair & Rasa
 

A bit of heat will do it, too.� Hold a match close enough to liquify the plastic end.� Don't set fire to it, and for heaven's sake remember that the plastic end is going to burn you if you touch it before it cools.� But it will work.

Blair


On 17/05/30 15:02, DAVID KLEMM davidklemm7511@... [WiringForDCC] wrote:

The easiest way to 'polish the end' is to use plastic�cement to melt the end clear. �It is what I do and works like a charm.



Re: Wiring

Cort Garnier
 

Thanks Steve! Currently I have no DCC locomotives yet and the box of my digitrack stuff arrived yesterday. Once the checks have been done I will install the DCC system and buy a dcc equipped loco. Still have some wiring to finish and tidy up the feeders. Thanks again!
 
Cort Garnier (210) 440-8411 cortgarnier@...


On Monday, May 29, 2017 8:57 AM, "glatiak@... [WiringForDCC]" wrote:


 
You could supply power to the track with a couple of alligator clips if you wanted to test sections. As for permanent wring, DC and DCC have the same issues of polarity. And if you intend to use a PM42 for power districting, a pair of barrier strips would substitute for the output side. And the distribution of power within the district if you intended to do occupancy detection can similarly be implemented. What I did when building my 7x10 two deck layout. The difference between the two is that DC voltage varies and DCC does not. Instead, signals are sent out to tell addressable devices to take more or less power.

greg latiak


Use of Forward/Reverse button

Brian Lewis
 

I was watching someone engaged in low speed shunting recently. He was using a NCE PowerPro and instead of bringing the loco to a halt and reversing the direction of travel, he was just pressing the Direction button.

Now my thoughts are that this is bad practice, calculated to encourage back lash on the gear train, to say nothing of the forces exerted on the commutator and thrust washers. But does it go further?  Does this reverse of current cause damage to the decoder? I would be very interested to hear your thoughts upon this practice.
--

Regards and thanks

 

Brian Lewis

Re: Use of Forward/Reverse button

dvollrath@...
 

With most decoders the settings of accel and decel in CVs 3 & 4 will moderate the transition from fwd to rev in the 28 speed step mode. However, the transition can be rather jerky if CVs 3 & 4 are set to zero. Not very prototypical operation and as you point out, possibly detrimental to the life of the decoder, motor and gears. There were a few early decoder models that treated the 128 speed step mode differently than the 28 step mode in this regard. Those did cause an abrupt change in direction and a big step in motor current if you pressed the direction button on the fly.


DonV    



---In WiringForDCC@..., <brian@...> wrote :

I was watching someone engaged in low speed shunting recently. He was using a NCE PowerPro and instead of bringing the loco to a halt and reversing the direction of travel, he was just pressing the Direction button.

Now my thoughts are that this is bad practice, calculated to encourage back lash on the gear train, to say nothing of the forces exerted on the commutator and thrust washers. But does it go further?  Does this reverse of current cause damage to the decoder? I would be very interested to hear your thoughts upon this practice.
--

Regards and thanks

 

Brian Lewis

Booster Advice

Blair & Rasa
 

Hi folks

I'm starting to contemplate my layout power requirements, and I need a sanity check (quiet out there).

I've between 6 and 800 feet of main line, one 4-60 foot branchline, and 7 yards ranging from two 16 track monsters, one junction monster, two end of line moderate yards, and two interchanges each boasting a half dozen tracks. I've laid out the booster positions so that no track point is more than 40' from a booster/PM42 location. In a couple of cases, one booster/PM42 feeds three levels of track, which encompass four differ mainline sections; in other cases, a Yard on one level takes two PM42 sections, while trackage above and below use the other two. PM42s will not be used for reversing, just power management.

All that being said, I find that I only have one location where I can justify an 8A booster; the rest will happily be managed by 5A boosters. In one case, I can actually envisage using a Zephyr as the booster for a PM42, as most of that trackage will see at most two trains, and generally not at the same time.

So I guess I'm asking, have others encountered this? In my case, my max-bus-length rules force me into far more booster/PM42 combos than I might otherwise purchase, given my expected track loading.

Blair Smith

Re: Booster Advice

Steve Haas
 

>>I'm starting to contemplate my layout power requirements, and I need a

sanity check (quiet out there).<<

>>I've laid out the booster positions so that no track

point is more than 40' from a booster/PM42 location.  In a couple of

cases, one booster/PM42 feeds three levels of track, which encompass

four differ mainline sections;  in other cases, a Yard on one level

takes two PM42 sections, while trackage above and below use the other

two.  PM42s will not be used for reversing, just power management.<<

      1) It sounds like you are determining booster positions and quantities based on a maximum bus length or 40'.  The number of boosters, with boosters being expensive items, is usually determined by determining the total power load of the of the layout (how many engines running at the same time, plus passenger car and caboose lighting) and then dividing by the amperage capacity of the booster (usually 5 amps for a N or HO layout).  Having done that, you can define your booster districts so no booster is expected to have more than a 4 amp load.

      2) You want to maintain a max length of bus runs of 40' - that's a reasonable upper limit. But, don't forget, you can split the booster output at the booster and run 40' (your designated bus length) in _each_ direction for 40'.  Beyond that, bus lengths can be extended further if the bus pairs are twisted (3-5 turns/foot), and R/C "filters" are used at the ends of the buses.

 >>All that being said, I find that I only have one location where I can

justify an 8A booster; the rest will happily be managed by 5A boosters.<<

      Conventional wisdom suggests that you limit yourself to 5 Amp boosters.  In a short situation the section of track served by that booster could potentially receive the entire 8 amps of current, and that's a hefty amount and could lead to damage to equipment.  Far better to use two 5 amp boosters in lieu of the 8 amp.

>>So I guess I'm asking, have others encountered this?  In my case, my

max-bus-length rules force me into far more booster/PM42 combos than I

might otherwise purchase, given my expected track loading.<<

      As I mentioned above, consider splitting the bus at the booster and run 40' in each direction, and create booster areas where the _expected_ max current draw on each 5 amp booster is between 3 and 4 amps - that leaves you a bit of ceiling room for the occasional extra current draw.

      I'm headed out on a long trip either Saturday or Sunday, and don't know yet what e-mail access I'll have on the way.  If/when I do, I'll check in to see if you have any followup questions.

      Others will also most likely step in to assist you, too.

      Best regards,

      Steve

      Steve Haas

      Snoqualmie, WA

Re: Booster Advice

Blair & Rasa
 

Steve.�

Thanks for the quick reply.� Halfway through writing that, I realized that a quick sketch of the layout and location selections was going to be needed to short-circuit a whole lot of back and forth.� I should have not posted until that sketch was available.� I'll post the sketch later today, but to give you a quick answer, 40' is half of the approximate distance between boosters.� Due to the topology of the layout, it makes sense to reduce that in some instances, to make more sense of the bus runs, but in general that's what I worked with.� The room is 28x52, and the layout is a 2 1/4 turn "nolix" running ccw up around the room, but also feeding three separate peninsulas running the length of the room.� So there's a lot of bench run.� All of this will become clear with a diagram.

Probably best if comments are held off until I give you all the diagram.

Blair



On 17/06/09 00:20, 'Steve Haas' Goatfisher2@... [WiringForDCC] wrote:

>>I'm starting to contemplate my layout power requirements, and I need a

sanity check (quiet out there).<<

>>I've laid out the booster positions so that no track

point is more than 40' from a booster/PM42 location.� In a couple of

cases, one booster/PM42 feeds three levels of track, which encompass

four differ mainline sections;� in other cases, a Yard on one level

takes two PM42 sections, while trackage above and below use the other

two.� PM42s will not be used for reversing, just power management.<<

      1) It sounds like you are determining booster positions and quantities based on a maximum bus length or 40'.� The number of boosters, with boosters being expensive items, is usually determined by determining the total power load of the of the layout (how many engines running at the same time, plus passenger car and caboose lighting) and then dividing by the amperage capacity of the booster (usually 5 amps for a N or HO layout).� Having done that, you can define your booster districts so no booster is expected to have more than a 4 amp load.

      2) You want to maintain a max length of bus runs of 40' - that's a reasonable upper limit. But, don't forget, you can split the booster output at the booster and run 40' (your designated bus length) in _each_ direction for 40'.� Beyond that, bus lengths can be extended further if the bus pairs are twisted (3-5 turns/foot), and R/C "filters" are used at the ends of the buses.

�>>All that being said, I find that I only have one location where I can

justify an 8A booster; the rest will happily be managed by 5A boosters.<<

      Conventional wisdom suggests that you limit yourself to 5 Amp boosters.� In a short situation the section of track served by that booster could potentially receive the entire 8 amps of current, and that's a hefty amount and could lead to damage to equipment.� Far better to use two 5 amp boosters in lieu of the 8 amp.

>>So I guess I'm asking, have others encountered this?� In my case, my

max-bus-length rules force me into far more booster/PM42 combos than I

might otherwise purchase, given my expected track loading.<<

      As I mentioned above, consider splitting the bus at the booster and run 40' in each direction, and create booster areas where the _expected_ max current draw on each 5 amp booster is between 3 and 4 amps - that leaves you a bit of ceiling room for the occasional extra current draw.

      I'm headed out on a long trip either Saturday or Sunday, and don't know yet what e-mail access I'll have on the way.� If/when I do, I'll check in to see if you have any followup questions.

      Others will also most likely step in to assist you, too.

      Best regards,

      Steve

      Steve Haas

      Snoqualmie, WA


Re: Booster Advice

Blair & Rasa
 

Okay, the question I should have asked.

I'm aware of the W4DCC recommendation of 30' maximums for bus length from booster. That can be as many runs in different directions as I can stand to wire up, or as the booster will tolerate once those runs are loaded with trains. I'm aware of the benefits of twisting the buss wires. I'm aware of the recommendation for snubbers beyond the 30' length.

What I can't seem to find is any data, guideline or even hint of just how much extra length a snubber "buys me". Can I have 50' runs with impunity as long as each is snubber-terminated? 60'? 70'? What experiences have others had? Ignore current requirements.

Regards

Blair

Re: Booster Advice

Steve Haas
 

Blair,

What I can't seem to find is any data, guideline or even hint of just
how much extra length a snubber "buys me".<<


You are seeking a guideline that doesn't really exist. A data point that
many have sought in the past (and many more will seek in the future<GRIN>).

A good electrical engineer or electronics tech could probably provide a
number derived from testing in a controlled laboratory environment, but that
number would apply only to that lab environment and exact replications of
that environment.

The real world of model railroad wiring and electronics is anything but a
controlled laboratory environment:

1) Each layout is in its own unique environment,
2) Each layout is unique in its track plan,
3) The selection of wiring materials in each layout is unique, and
4) The skills of the individual(s) doing the wiring are unique.

Because of this there is no "magic bullet" answer to your question. A
layout's track and wiring has been described by those who understand all
this as one large antenna, capable of both capturing and generating noise
that can impact the performance of our systems, layouts and trains.

Because each layout is unique, no one can state with any certainty what
problems will rear their heads at what point in that environment.

Because of this, both vendors and DCC gurus (I'm not a guru, just a mere
disciple!), recommend the precautions they do, the major precautions being
twisting buses 3 - 5 times per foot for runs longer than 30', and "Snubbers"
at the ends of buses longer than 30' or so. The longer the bus, the more
likely the problem will arise, and the more likely a Snubber will help.

The good news is snubbers are cheap to make, easy to install, and they have
no negative impact on the layout - They might not really be needed, but they
will never have a negative impact.

Can I have 50' runs with impunity as long as each is snubber-terminated?
60'? 70'? What experiences have others had? Ignore current requirements.<<

I worked on a local layout for 13 or so years. System was DCC, in a 28' x
42' outbuilding. Prior to my participation, the owner had centralized* his
DCC command station and boosters all in one corner. To get to the opposite
corner of the room, bus wires had to run the length and width of that
building, and back part way across the other long side of the building - a
bus run in excess of 80'. Initially, we had a _lot_ of problems with
decoders "losing their minds" and requiring a trip to the programming track
to resurrect them. When we installed additional PSX circuit breakers (also
centrally located), breaking "booster districts" down into "PSX Districts",
we ran additional bus lines from each PSX out to the district it controlled.
These were not twisted (we should have), but they were all together in a
bundle, with each pair splitting off from the trunk to serve its designated
area. Locally at each end of the bus, we installed snubbers.

As work progressed on this project (it took us a while), layout performance
improved during operating sessions, and the number of engines I took home
after each session continued to drop - to the point that I was only
re-programming one engine once or twice a year.

I would consider recommendations of max bus length to be "design goals",
rather than "absolute lines in the sand". The corollary to that is farther
you push the limits, the more you must pay attention to and apply the
techniques of twisting and adding snubbers to the wiring.

One other thing to remember, its only a layout, and if you do have problems
with the wiring, it _can_ be corrected! Granted, it is easier to do it right
the first time.

One thing I thought of while writing this response: in your plan, are
boosters centralized in one location for the entire layout, or are they
distributed throughout the layout, close the track they power? Your layout
room doesn't see so large that four boosters, one on each wall or the room,
serving track along that wall would probably suffice.

Food for thought.

Best regards,

Steve

Steve Haas
Snoqualmie, WA

Re: Booster Advice

Blair & Rasa
 

Steve

Um, I are an electronic tech. My employer thought I was good enough to
retain for 30+ years, including not taking away my tools towards the
end, but that may have no relevance.

Yep. I can do all the controlled experimenting I want, but it's
real-world experience that I'm looking for. What your really saying is,
no one will go out on a limb and say "do this, and it will work",
because the biggest remaining variable is the readers attention to
detail and physics. I appreciate what you've said at the end, I don't
think I'll have any problems with this then. It's up to me. See attached.

Bear in mind, the layout is mixed 2 and 3 level (B-B3 and C1-C), and
that the upper level of both the A and B peninsulas have interchange
yards between the mainline of my focus railroad(ACR) and the staging
yard level(CNR/CPR) that feeds the to-be-interchanged railroad on and
off layout. You'll probably have questions if you dig into it, if so
fire away.

<Attachment likely stripped from list>.

Blair

Re: Booster Advice

dvollrath@...
 

Blair, There are no hard and fast, right or wrong rules. Twisted pair wiring helps. But there is nothing wrong either about placing extra snubber filters along the DCC distribution bus every 20-30 ft or so. Yes, one purpose is to 'terminate' the DCC bus at near the characteristic impedance of the DCC transmission line (100-150 ohms) to minimize transmission line reflection effects of the abrupt voltage transitions of the DCC voltage wavefom. But a secondary purpose is to snub or absorb transient energy peaks caused by inductance of the DCC lines and intermittent connections to locomotive loads or sparking short circuits. Placing several filters along longer distribution lines can help prevent unwanted effects. Locos that don't seem to respond at certain parts of the layout and scrambled CV values are some of the first symptoms of problems due to those effects. Blown decoders are rare, but do happen when poor wiring practice is coupled with long lines, powerful boosters and sparking short circuits.


DonV

Re: Booster Advice

Blair & Rasa
 

Don

I think I've resolved this, with the help of a couple of offline
responses. Agreed, there are no magic numbers, but between resistance
of long runs and the need for snubbers due to the inductance issue, I
think I've settled on a plan that will see no run much more than 40',
and a booster arrangement that satisfies my need to minimize. There
will be three booster locations, two of which will have 5A boosters each
feeding a PM42, and one location with an 8A booster which will feed two
PM42s. Should I find that the current requirements are higher than
expected, I would purchase one more 8A booster, and place those at the
single PM42 locations, while splitting the two PM42s at the third
location so that each is fed from it's own 5A booster. Simple, and
upgradeable without major wiring changes.

I've attached the plan for your entertainment. it's a 2/3 level layout.

Regards

Blair



On 17/06/10 15:37, dvollrath@... [WiringForDCC] wrote:


Blair, There are no hard and fast, right or wrong rules. Twisted pair
wiring helps. But there is nothing wrong either about placing extra
snubber filters along the DCC distribution bus every 20-30 ft or so.
Yes, one purpose is to 'terminate' the DCC bus at near the
characteristic impedance of the DCC transmission line (100-150 ohms)
to minimize transmission line reflection effects of the abrupt voltage
transitions of the DCC voltage wavefom. But a secondary purpose is to
snub or absorb transient energy peaks caused by inductance of the DCC
lines and intermittent connections to locomotive loads or sparking
short circuits. Placing several filters along longer distribution
lines can help prevent unwanted effects. Locos that don't seem to
respond at certain parts of the layout and scrambled CV values are
some of the first symptoms of problems due to those effects. Blown
decoders are rare, but do happen when poor wiring practice is coupled
with long lines, powerful boosters and sparking short circuits.


DonV





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