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Setting up layout for both DC and DCC

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  • Member since
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Setting up layout for both DC and DCC
Posted by CascadeWestern on Saturday, December 29, 2018 7:45 PM

I just joined the forum about 30 minutes ago and am hoping for an answer to this question:

We face a dilemma in our club. Having been just given a new building last year, our HO layout is also new. It's currently temporarily wired for DC operation, but we have all the components to set it up with a Digitrax system, which we used on an isolated section of our old layout.  Now, the HO modelers are divided: some want the entire layout to be DCC, while others want to be able to switch the entire layout between DC and DCC, using a DPDT switch, center off, with power to the track coming from the switch's center terminals, and DC input coming in one set of end terminals and DCC input coming in at the other pair. Theoretically, , this would switch the entire layout to one or the other, without interference from the system not selected. Other members insist this won't work.  Is the dual approach feasible, and, if so, would there be any difference in the layout wiring?  We figured we could divide the layout into blocks either way, with the "blocks" becoming power districts in DCC,  Please help us figure this out, or provide a reference to resources we can review to get an answer. I'm under fire no matter which way we go!
 
Thanks.
Gene Conley
Magic Valley Model Railroaders
Twin Falls, ID 
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Posted by richg1998 on Wednesday, January 02, 2019 10:57 AM

It can be done but there is a chance you can smoke a booster. Our club did that.

We built a DC layout in the early 1980's. Fourteen blocks, one reverse loop. The control panel was operated by one man. Four throttles. Homemade throttles good for two amps each. Four operators. You guess it. With talkers, at times, who has my loco?

When we bought a NCE five amp Power Pro years later, we tried running DCC in a block or two and DC in some others. Eventually it bit us.

A few years earlier while some of us gabbing we ran a pricey diesel off a siding not finished off the layout damaging it. Lost a good member.

Probably loose membership standards at the time.

I think some DCC devices will not work under DC control such as DCC reversers and DCC turnouts. Actually anything that requres a signal from the operators DCC controller. There will be DC on the rails.

Rich

If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.

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Posted by RR_Mel on Wednesday, January 02, 2019 11:58 AM

I’ve been operating my layout in Dual Mod for years without any problems.  I also use a DPDT arrangement for switching.  As I’m getting up there in age and I’m not as alert as I was 30 years ago so I built in a safety interlock into my switching.  I went with a DPDT relay driven from the DC power pack AC accessory out put.  When I turn on the DC power pack the relay pulls in and switches the track from my DCC controller to the DC power pack eliminating any possibility of operator error.
 
 
 
The DC Power pack Accessory output is normally AC so you need to put a bridge rectifier in series with a DC relay coil as shown in my drawing.  You could use an AC relay but the relay will buzz.  The relay in the picture above is a 4PDT 12 volt DC relay, I paralled the contacts for higher current and longer contact life.  It's been working for about 13 years without a single problem.
 
Mel
 
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 
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Posted by wvg_ca on Wednesday, January 02, 2019 12:17 PM

auto reverse for DCC will not function correctly under DC , it will have to have one of the input wires disconnected for DC operation

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Posted by wjstix on Wednesday, January 02, 2019 12:49 PM

If you can set it up with one 'master switch' so the entire layout is either running on DC or DCC, it's not a problem. Where people mess up is setting it up so it's possible to have one block running DCC and another next to it is running DC. That can lead to problems.

As mentioned, if you use automatic reverse loop gizmos in DCC they won't work in DC, but you can use the old-fashioned DC method of throwing a toggle to reverse polarity in DCC also.

Stix
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Posted by mbinsewi on Wednesday, January 02, 2019 3:50 PM

I can switch from DCC to DC on my small layout (although I can't remember the last time I ran it DC), but I have a small layout, and I'm the only operator, a lone wolf.  It's only me running trains.

I think as a club layout you should have as Stix and Rich suggest, being able to switch it all one way, or all the other, and NOT try to mix operations.

It will come back and bite you sooner or later.  Too many different people and different equipment involved to have major problems like that.

Mike.

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Posted by drgwcs on Wednesday, January 02, 2019 4:28 PM

I have a DPDT switch on my layout where I can switch between DC and DCC. It MUST be a center off DPDT to work right. However my railroad is wired as one block. If you have multiple blocks/boosters and miss throwing one of the switches the results could be disasterous when a loco bridged the gap. It could fry the decoder or even the dcc system. There is a huge difference in having a home layout that is DCC vs  club layout. On most home layouts there is one operator so that really doesn't require DCC as much. The problem is many people project that thought onto a club layout. Once you have DCC on a club layout you wouldn't want block control- done both, there is no comparison everybody has individual control with DCC. I think our club here had some hurdles when it decided to go DCC (long before I came) The main one is someone will not want to as all their locos are DC and they don't want the cost. Perhaps if the club offered to convert one loco with a non-sound decoder for someone that was unable to that would go a long way in keeping the peace. Just a thought- that worked for us.

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Posted by rrinker on Wednesday, January 02, 2019 5:28 PM

 With a DPDT center off switch, one side feeding DC to the layout, the other side feeding DCC - there's no way you cna fry anything. The two systems do not connect in any way, and either the entire layout is either DC, or DCC, never both. I don't know why anyone would say this won't work. 

                                           --Randy


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by PC101 on Saturday, January 12, 2019 9:27 PM

One club layout set up for DC and DCC, How's that going to work? Odd days DC, even days DCC. Flip a coin that night of ops? Ok lets have a show of hands for tonight, DC... DCC... the DCs have it, you DCC guys can stay and watch or go home.  Whats that burning smell? What was the crunching noise? Opps, who's was that, that should not have been left sitting on the track. What I have seen happen when a club goes totaly DCC, is dues go up, the DCC guys push out alot of the totaly DC guys, membership drops, dues go up. Club picks up new members with DCC equipped locos and the dues stay up. Then some DC guys slowly convert. Go fully DCC and don't look back. Once every month or every three weeks have a DC club member only raffel, one good DCC decoder to be won by DC only members in good standing modelrailroaders, up to two wins perperson allowed. Then a club member should assist the winner on the install and setup at least twice. In the begining I hated DCC, felt like it was being crammed down my throat. But after a few years of a DC/DCC HO layout, I buckled and converted some locos. from DC to DCC. Wow, that was a plus all round. Over the past years I have been pulling out some DCC decoders and installing DCC sound decoders. So now I'm wondering what to do with some of those NOS Atlas #340 & 342 no sound DCC decoders I stock piled? Oh, the raffel prizes would be a nice start.  

But it all comes down to tne voteing membership which way it goes.   

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Posted by rrinker on Saturday, January 12, 2019 10:04 PM

 See the problem is, the DCC guys can run on the DC layout, but the opposite is not true. Only some older DCC decoders did not support running on DC. The will probably not be able to MU a DCC loco with a straight DC one, and ones with DCC sound locos will be rather dissapointed in the performance, but anyone who sees what the same sound loco does when running on DCC will either see how much better it can be, or swear off sound locos for good.

 We have plenty of members who are DC only at home, they have one or two locos with decoders that they use at club shows. Or run someone else's. I'm not alone in being paranoid about letting someone else run one of my locos - I don;t have any megabuck brass locos, with the exception of a few sound locos that came factory equipped, most of my locos were $50 and less through careful use of eBay. So if someone else wants to take my train out for a while - go right ahead. There's no way a loco can hit the floor on our layout, there's no place the track somes close enough to the edge for that. So, if you don;t have a DCC loco and want a chance to run a train for a while - here, take my throttle.

                              --Randy


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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