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Both DC and DCC available to one section of track?

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Both DC and DCC available to one section of track?
Posted by m sharp on Saturday, May 11, 2019 6:24 PM

I am building a layout with one main operating with DC, and the other set DCC.  I would like to be able to have a DC powered consist to cross over to the DCC main on a section of track, if that is possible.  Of course nothing will change regarding the locomotives' power system, but I would think by changing the power source on that section of track that it should work.  It seems to me that as long as the wiring was adequate, and blocked properly, it should work.  Does that sound right?  Thanks.

Mike

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Posted by rrinker on Saturday, May 11, 2019 7:35 PM

 Under no circumstances can DC and DCC power be in the same track. 

Only certain DCC systems can run a DC loco, and then it's not really all that great. So there is really no reason to move the DC train over to the DCC track.

If you want to use both, your best best is to get a DPDT Center Off toggle and wire it so that the entire layout is DC or the entire layout is DCC. Or keep a completely isolated DC loop. Crossing gape between the two can damage the loco, the DC power pack, and the DCC booster. Just - don't.

                           --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 jjdamnit on Saturday, May 11, 2019 8:27 PM

Hello All,

Here's just a few previous posts...


DC and DCC operation?


How to hookup ~ DC + DCS + DCC together


Wiring Layout for both DC & DCC


Wiring layout for both DCC and DC


I keep frying decoders when running on DC

Happy reading and...

Hope this helps.

Post Script:
The only way I could envision what you are proposing is having one loop on one control system and an angled crossing over the other loop with the other control system.
Neither of these control systems would overlap.
BUT...and it's a big but...If one piece of rolling stock jumps the rails at the crossing it's literally and figuratively "lights out"!!!
HTH, J.J.

"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"

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Posted by SPSOT fan on Saturday, May 11, 2019 10:54 PM

I have a friend who wire his main line so he could divert just the main to regular DC and still run the rest on DCC. So it is possible to do that. Now I have no idea how much crazy wiring went into that but I know the person in question is a very competent and advanced modeler.

As to switching one siding from DCC to DC I don’t think it will be terribly complex. All you would need to do is insulated (through plastic railjoiners or other meathods) the siding and have a switch to flip between DC and DCC power.

Do note, my friend I mentioned earlier admitted he NEVER used his DC main, and though it’s a good idea, he found it to be a bit overkill. So only do all this double wiring for DC if you’re certain you will use it.

Regards, Isaac

I model my railroad and you model yours! I model my way and you model yours!

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Posted by gregc on Sunday, May 12, 2019 7:04 AM

m sharp
I am building a layout with one main operating with DC, and the other set DCC.  I would like to be able to have a DC powered consist to cross over to the DCC main on a section of track ...   but I would think by changing the power source on that section of track that it should work.

It seems to me that as long as the wiring was adequate, and blocked properly, it should work.  Does that sound right?

it sounds like you know what you're talking about.  How electronic savy are you?

presumably you understand that there are problems if the metal wheels ever bridge the gaps between a DC and DCC block.

not sure if you're talking about  a crossing

or a section of track being either DC or DCC.

it's possible to make both tracks of the crossing isolated from one another or isolate the entire crossing and have some detection that powers the crossing with either DC or DCC.

it would also be possible, using detection and turnout positions to have a common section of track that is powered from either DC or DCC.

good luck

greg - Philadelphia & Reading / Reading

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Posted by RR_Mel on Sunday, May 12, 2019 7:16 AM

If what you want to do is like what Greg suggested it might work.  A drawing or diagram of what you are trying to do would help, otherwise Randy’s advice is dead on.  In no way should DC ever connect to a DCC system, even momentary would do damage.
 
 
Mel
 
 
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Posted by tstage on Sunday, May 12, 2019 9:03 AM

m sharp

I am building a layout with one main operating with DC, and the other set DCC.  I would like to be able to have a DC powered consist to cross over to the DCC main on a section of track, if that is possible.

m sharp

I am building a layout with one main operating with DC, and the other set DCC.  I would like to be able to have a DC powered consist to cross over to the DCC main on a section of track, if that is possible.

I don't think the OP is referring to a crossing (like Greg's example) but a crossover or section of track to migrate from one main to another.  Either way it's a bad idea.

Yes, separate mains could cross one another safely.  However, if there should ever be a derailment right at the crossing and the metal wheels on the rolling stock short the DC to the DCC ..*poof*...there goes your DCC system, DC system, or both.

Mike, run one or the other (i.e. either/or) using a DPDT switch if you'd like but do NOT run them simultaneously.  Just don't do it...

Tom

http://www.newyorkcentralmodeling.com

Time...It marches on...without ever turning around to see if anyone is even keeping in step.

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Posted by gregc on Sunday, May 12, 2019 9:40 AM

tstage
However, if there should ever be a derailment right at the crossing and the metal wheels on the rolling stock short the DC to the DCC ..*poof*...there goes your DCC system, DC system, or both.

not sure that either system would be damaged if either or both have short circuit protection.

i'm sure many would not want to find out, but that's what it's there for

greg - Philadelphia & Reading / Reading

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Posted by mbinsewi on Sunday, May 12, 2019 9:47 AM

I can run my lay out in DC, or DCC, but I NEVER run both at the same time.

I know to the OP this seems like a simple task, having one cross the other, and if he wishes to pursue it, and comes up with a system or series of toggles, relays, electronics, etc., to pull it off, it's his railroad and equipment that will suffer any damage if something goes wrong, NOT mine.

All I say is good luck.  

I don't understand why he wants to do this Indifferent  Having a main line for each system, and to go from one to the other, or even to cross the other.  NOPE. 

Mike.

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Posted by floridaflyer on Sunday, May 12, 2019 11:14 AM

I believe that the OP wants to have a section of track between the inner and outer loops that can be changed from DC to DCC. That could be done with a toggle switch. Section of track would probably have to be as long as the train. train would enter from the DC side with the section of track set for DC. Train would probably stop within the section of track and the power would be switched to DCC and the train would then proceed to the DCC loop. So yes it could be done, but the overall idea has dangers as Randy has pointed out, and I wouldn't do it.

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Posted by mbinsewi on Sunday, May 12, 2019 11:30 AM

m sharp
I am building a layout with one main operating with DC, and the other set DCC. 

What do you mean by "set" ?  Is this a double track main? one main DCC and the other DC ?

m sharp
I would like to be able to have a DC powered consist to cross over to the DCC main on a section of track, if that is possible. 

This sounds to me like the OP wants to move a DC powered train, off the DC track, and, move over to the DCC controled main. ??  

I guess we'll have to wait until he responds to his thread, and find out exactly what he wants to do.

Mike.

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Posted by MisterBeasley on Sunday, May 12, 2019 11:58 AM

I agree with Randy. Don't do it.  Don't even try.

Put decoders in all your DC engines, if you must, and run pure DCC.  Or, run just DC in compatibility mode.

When I ran my first DCC train, I took the old power pack on put it under the table.  I never went back, and never wanted to.

It takes an iron man to play with a toy iron horse. 

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Posted by richg1998 on Sunday, May 12, 2019 12:26 PM

About nine years ago our club wiped out an NCE Power Pro five amp booster because we thought we could do that. Our home made DC throttles were capable of 2.5 amps.We use to run two or three locos at one time when we ran DC. We could match diesels.

We never allowed DC and DCC after that.

Rich

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Posted by m sharp on Sunday, May 12, 2019 12:28 PM

Here is a track diagram of what I propose.

https://live.staticflickr.com/65535/40866434723_6eabb00f59_h.jpg

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Posted by m sharp on Sunday, May 12, 2019 12:42 PM

The only reason I want to do something like this, it's because most of my locos were purchased in the 80s and 90s, and I don't have the resources or time to put decoders in most of them (over 200).  I plan on getting decoders for many of the older engins, but that will take years to accomplish.  At this time, I have just about 10 DCC equipped engines, but I have a system and would like to use it.

Another option may be to wire all of it for DC, then change over to DCC at some point after I have enough decoders installed in the plder equipment.  I don't want to do that, because it would prohibit me from using a group of locos for many years to come.

Mike

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Posted by RR_Mel on Sunday, May 12, 2019 12:56 PM

If you run in DC mode for your DC locomotives and switch the entire layout from DC to DCC to run your DCC locomotives it very doable.  I operate like that too. 
 
I use a 12 volt DPDT relay to switch the rails from my DCC Controller to my DC Power Pack.  To insure no screwups the relay is powered by the Accessory power from the DC Power Pack.  When I turn on the DC Power Pack it automatically disconnects the DCC Controller and connects the rails to the DC Power Pack.
 
That would work for you also, but you can’t run DCC locomotives when you are in DC mode.
 
 
Mel
 
 
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Posted by SPSOT fan on Sunday, May 12, 2019 12:59 PM

I think if your willing to put the fpeffort nessesary for installing partial DC on your layout, it may be worth it. However you NEED to be VERY CAREFUL not to mess up any wiring and blow up your DCC stuff.

You may want to evaluate wheather it’s a better use of your time to make a complicated DC/DCC system or just put some time into adding decoders to your locos. Remember you can always run DC engines with your DC system using address 0.

If you chose the hybrid DC/DCC way, put time into doing it right. You MUST do it correctly, take ZERO shortcuts!

Regards, Isaac

I model my railroad and you model yours! I model my way and you model yours!

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Posted by mbinsewi on Sunday, May 12, 2019 1:12 PM

So, wire your lay out so you can run one or the other, but DON"T try mixing them.  

As I mentioned in my post, I can go DC, or DCC.  When I built the lay out, I wired it using a buss, and feeders, and divided into "blocks", like you would for DC cab control, only I gapped both rails.  I didn't use common rail method, as many DC cab control lay outs do.

When I want to run DC, I unplug the DCC system I use, flip toggle switches, and plug in the DC throttle.

I was/am the same as you, all my decent locos were DC.  Now it's been a few years, I have aquired some DCC locos, and slowly installed decoders in the best running DC locos I have.  

I pretty much just run in DCC now.  It's been a couple of years since I ran the lay out on DC, but I have the option to do so, when I wish.

And you CAN run DC locos on a DCC system, on my Digitrax, I set the address of the DC loco to "00".  I'm not sure about other systems, there was a thread recently about this.

With my lay out on DCC, I found out I can run a DC loco, on address "00", and also run a DCC loco with it's own address, and have seperate control of both locos.

If you try mixing, running both DC and DCC at the same time, your asking for trouble, expensive trouble.

Mike.

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Posted by gregc on Sunday, May 12, 2019 2:16 PM

m sharp

https://live.staticflickr.com/65535/40866434723_6eabb00f59_h.jpg

this looks like an intriguing problem.   Part of the challenge in that the route can be either DC or DCC.   It's only when that bottom left turnout is routed to the bottom DC track do you want all the blocks in blue switched to DC.

i like the idea of using dpdt latching relays that can reverse the polarity to control Tortoise switch machines.   A diode matrix approach can be used to route a pulse to the relays to select a route.   The same approach can also be used to control additional relays that power those blocks with DC or DCC. (of course a diode matrix would make route selection easier even w/o DC).

a hazard is a DCC locomotive running thru a turnout from a non-diverging end bridging the gaps between DCC and DC.   Additional relays could also be used to create stopping blocks on the DCC sections adjacent to the turnouts. (make long enough to handle keep alives).

 

greg - Philadelphia & Reading / Reading

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Posted by RR_Mel on Sunday, May 12, 2019 2:17 PM

If you are interested in doing dual mode DC OR DCC this is the way I wired my layout, automatic switching . . . . no way to screw up.
 
Click to enlarge
 
 
I went with a DC relay and a full wave bridge rectifier instead of an AC relay (the Accessory output from my MRC DC Power Pack is AC) is to prevent the AC buzz of the relay when running in DC mode.
 
 
 
 
Mel
 
 
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Posted by MisterBeasley on Sunday, May 12, 2019 2:50 PM

Remember, not all DCC systems support the Engine Zero option.  My Lenz system does, but some do not. 

It's a weak choice.  DC engines on my layout will only run at half speed or so, make a lot of noise, and auto reversers will not work.

It takes an iron man to play with a toy iron horse. 

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Posted by richg1998 on Sunday, May 12, 2019 3:25 PM

My first DCC system was a MRC2K with five throttles. Throttle one could run a DCC or DC loco. Never had an issue with half speed.

I could run a freight with a DCC loco pulling and a DC loco pushing.

Yes, the DC loco buzzed. I would park it when not using it. The motor brushes get hotter where they contact the armature when the loco is stopped and DCC still on the rails.

The AC component vibrated the motor armature at the DCC frequency. I did temp measurements with an infra red temp scanner on a loco wheel rack.

Gave the system away and went full DCC.

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 m sharp on Sunday, May 12, 2019 6:25 PM

Thanks everyone.  It sounds like I need to put a lot of thought into this before charging ahead.  I have a Digitrax system (beginners model).  I am by no means great at wiring, so that will probably make my decision that much easier.

Mike

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Posted by richg1998 on Sunday, May 12, 2019 8:26 PM

The reason you get answers like this is because new DCC users are the ones who ask. That is what happened at our club. One person was not paying attention to the control panel for block control. Gabbing.

Just be very careful that there will be no possible way for the loco, tender wheels to contact DC and DCC rails.

Post a diagram here of what you would like to do.

Someone with electrical experince can do it.  Maybe a lone wolf. We could have but, talk, talk, talk.

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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