# DCC on DC



## SlowRoll (Apr 2, 2019)

Hey all. I’m new to the forum and I’m reading through threads and I’m certain all my answers have previously been typed out here but...... Basically I’m looking to build a 4x5ish N scale layout with an elevated main line. I’m new to N scale so will be purchasing N scale locomotives and cars. DC is more in the budget but DCC sound and operations are a distant goal. So I figured, build an elevated DCC main line for DCC locomotives I purchase and a lower level for less expensive DC locos that are DCC ready for future consideration. I hear running DC locos on DCC wired track burns out the motors quickly and that makes sense. Am I thinking correctly?
Thanks!
Your newest noob,
SlowRoll


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## mesenteria (Oct 29, 2015)

Wipe your mind clean, grasshopper. All done?



DC is just a can motor turning on the basis of voltage that you put to the rails. You control how much voltage by turning a rheostat on your power pack at the side of the tracks. Turn the knob clockwise, and the voltage rises. Turn it more, it gets more voltage and the train speeds up. 

DCC is like the knob being turned all the way to the right as far as it will go right from the outset. Full voltage right away. The train should take off like a scared cat...…………..right? No.

The reason is that there is a brain in the way. There's a microchip that reads the voltage. Because it's a digital voltage, it's actually a square wave, meaning it goes up, time moves and the voltage stays positive, but then it goes down immediately and stays negative. The time between these events is what gives the motor more power to use to move the locomotive, and by extension, any cars trailing behind it.

The problem you may have read about is that the square wave, which is actually an AC current, not DC, changes phases so many times each second, and this confuses a can motor that doesn't have the brains and software interpreting the digital current. The AC current...remember. With DC, one rail carries negative polarity, and the other positive. All the time, unless you switch polarity, which you do with a toggle, and then the locomotive will run in reverse.

With AC, it's only the phase that changes, so the two rails swap polarity many times each second. But, there's still the 'push' of the total voltage behind these rapid swaps, and that makes the poor can motor growl, squeal, and groan. And heat up eventually. Baaaaddd!

Wiring for either type of power, for your purposes, early in the hobby, is exactly the same. Two rails, one to each rail. Then, you hook up whichever power type you want to use. If it's DCC, then your locomotives must have a decoder installed, and then your drive mechanisms will be 'driven' themselves by the brains. If you want to operate in DC for now, same thing: two wires, one to each rail. Except you can have a decoder if you want, or none at all. The reason is that modern decoders will sense what type of power is being delivered to the rails and act accordingly. But, a non-decodered, non-DCC locomotive, won't know what to do with digital current, the square wave, full voltage, AC current.

Kapeesh?


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## SlowRoll (Apr 2, 2019)

mesenteria said:


> Wipe your mind clean, grasshopper. All done?
> 
> 
> 
> ...


Thanks for your reply! Unless I am miss understanding, and that is most likely the case, the explanation doesn’t give me a way to comfortably run both DC and and DCC locos on the same layout without wiring one track this way and the other that. I apologize for my lack of understanding and appreciate your understanding. 

Thanks!


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## luvadj (Jul 3, 2017)

It is possible to run either DC or DCC but not both at the same time via a DPDT switch; switched one way for DC and the other for DCC which is how my layout is setup


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## cv_acr (Oct 28, 2011)

Some older DCC systems would allow you to run analog DC engines on address "0"; it would adjust the signal somehow to actually give a bit more to one side so the engine(s) moves.

However as mesenteria describes above, it's not exactly recommended to do this, as it's still putting an AC current through a DC motor.

I think that some newer systems don't even have this option anymore.

On the other side of the coin, some (but not all) DCC decoders are "dual-mode"; their electronics will detect a DC current and respond to it. It will take a little bit more voltage than a non-decodered locomotive since the electronics are in there, so you wouldn't be able to couple a pure analog DC loco and one with a dual-mode DCC decoder in one set as the non decodered one will probably run a bit faster at the same voltage.


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## DonR (Oct 18, 2012)

Slowroll

As has been posted, there is no difference in
the way DC vs DCC tracks are wired.

You simply connect the two wires from your
DC power pack so that all tracks get power.
The same if you have a DCC controller.

You would do serious damage to any DCC power
pack that is connected to a track that also gets
DC power.

Also, as stated, you can run SOME DCC locos on
DC tracks. However they may not perform as well
as they would on a DCC track.

However, you are best advised to buy only DC or
DCC READY locos until you have a DCC controller.
(A DCC READY loco is simply a DC loco that can
be updated to DCC by plugging in a decoder).

Don


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## mesenteria (Oct 29, 2015)

To our OP, and it has been said by others, you cannot run both types of power simultaneously. One or the other, not both. A toggle switch will allow you to switch between the two at will.

The problem with strictly DC can motors subjected to DCC current, with its digital signal, is that the rapid changes inherent in all AC current makes a DC motor buzz, vibrating really. It can't turn unless the digital current is altered by the DCC system to allow some turning, but meanwhile this buzzing and squealing motor is getting full voltage. It will get progressively warmer until if fries.

However, modern decoders can be programmed in what is called a Configuration Variable (or CV), and it happens to be CV29 that makes the decoder read the power to sense which type it is getting from the rails. It can act one either one, but only with DCC current will the decoder behave will full capability and allow you to do all a decoder can do.

Most of us who operate strictly in DCC disable this 'dual mode' sensitivity because of a rare but catastrophic glitch that happens with DC current. Some decoders, when the rails first get the surge of power at startup, will think they are getting full DC voltage, and not the full DCC voltage. Full DC voltage means full speed, and that's what they'll promptly do...a jackrabbit start and tear around the layout. Some have reported losing a locomotive off the edge of a layout as it careens off the rails around a curve that is close to the table's edge. Or, they'll run away and fall off the end of a rail that meets a swing-down bridge you use to get into your layout room.


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## SlowRoll (Apr 2, 2019)

Wow guys, some excellent info here. Thanks to all that took the time to reply. It’s great to be in such a knowledgeable and experienced group! My initial thought (and maybe it didn’t come through in my first post at the start) is that I was thinking of having an elevated track system completely separate from my lower track system. Completely separate. Like one fully functioning layout stacked on another independently and larger fully functioning layout. And just running DCC on the top and DC on the bottom layout. The track systems never encountering each other. I’m gathering that either that is an idiotic idea or that I didn’t explain myself properly. Basically the idea was to have a few older locos that I have and a few cheaper to afford new locos that are not DCC ready or equipped be able to run around on the bottom DC layout while a nice new exciting DCC with sound loco crawls around up on the top layout. I’m sure I am completely missing the point and I apologize in advance hahaha. 
Thanks guys!


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## 65446 (Sep 22, 2018)

SLOW ROLL, I don't think it's been covered yet: You certainly CAN run both at the same time if the upper and lower tracks are not connected to one another in any way, and you have a DCC controller for the upper tracks and a separate analog DC power pack for the bottom tracks..


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## Lemonhawk (Sep 24, 2013)

No, Slow Roll your thinking is correct. As long as the top track never interacts with the lower track then you can have the top track DCC and the lower track DC. That may be better than a DPDT toggle switch that switches your entire layout. Imagine you have a few DC locos on your DC layout when you shut down for the night. A week later you decide you want to run DCC so you throw your switch from DC to DCC and put your latest DCC/sound on the track, and are having a great time. Then you start to see and smell smoke, that's those DC loco's your forgot about! So keep them seperate, and then soon put cheap decoders in you DC locos and convert to all DCC.


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## SlowRoll (Apr 2, 2019)

Thanks all. Here is yet another noob question if you will be patient with me. I see locomotives advertised that contain a DCC chip but no grand announcement of SOUND. If I’m going to pick up a DCC locomotive I want it to be sound equipped. Is a DCC equipped N scale loco without sound difficult to equip with sound?
Thanks all!

SlowRoll.


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## PoppetFlatsRR (Jul 29, 2018)

SlowRoll, 

What I have found over the last two years, is that the added on sound works, but buying the locomotive with sound seem to work better. Broadway Limited sound seems to me to be the best, but their a little finicky about track conditions. 

I have given up on everything but Kato, I only buy Kato locomotives and use their Kobo shop for the sound ones. Kato's just run better on my layout for some reason.

On installing the sound board, I really have no idea. My eyesight is not good enough to do it. The Kobo units from Kato are ESU Loksound. Pretty loud compared to others.


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## mesenteria (Oct 29, 2015)

Well, you can learn, but if you are middle aged, or the least impaired manually and/or visually, N Scale is tough. Generally, the better job will have been performed by the 16 year old women in China at the assembly lines. I'm dead serious.

However, as a perhaps unwelcome aside, and I may take some flack for this (and all my HO locomotives have sound):

The smaller scale items with sound don't sound so great. Some 're better'n others, to be sure, and a lot depends on the know-how and skill of the installer, but the small spaces in HO scale and on down means tinny sound. Tiny sound, too. Many can't stand it after a while because it is low-fi sound, and they run their more expensive locomotives in silence.

I say this because you may find yourself quite disappointed with the small, tinny sound that will issue from N scale enclosures. Sorry, it's just physics...


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