Getting power?

[doug1980]

I have been modeling for 9 years but never made a layout that would actually run. Always made shelf layouts without ovals so never worried about wiring or anything. I seen a layout that was similar to what I want to make but it was operable. So my question is how can this be done? Also if I did decide to make a normal layout to run trains what is the difference between DC and DCC? I would probably only run 1 train maybe 2 with two loco's and 10-12 cars.

 

[UP2CSX]

Doug, you lost me on the layout question. Do you mean you saw a layout with continuous running and wonder how the the wiring was done? If you wired track for a shelf layout, there's really no difference in wiring a loop. You may need more feeder wires depending on the layout size so you get reliable power throughout the oval but, other than that, wiring track is wiring track.

There's an excellent comparison of DC vs DCC at http://www.dccwiki.com/DCC_advantage_over_DC. DC is kind of like trying to maintain and fly an F-100 and DCC is like maintaining and flying an F-32. Both can be done but it's a lot easier using new technology and the ejector seat's a lot better.

 

[doug1980]

Doug, you lost me on the layout question. Do you mean you saw a layout with continuous running and wonder how the the wiring was done? If you wired track for a shelf layout, there's really no difference in wiring a loop. You may need more feeder wires depending on the layout size so you get reliable power throughout the oval but, other than that, wiring track is wiring track.

There's an excellent comparison of DC vs DCC at http://www.dccwiki.com/DCC_advantage_over_DC. DC is kind of like trying to maintain and fly an F-100 and DCC is like maintaining and flying an F-32. Both can be done but it's a lot easier using new technology and the ejector seat's a lot better.

Thanks for the info. I saw in a magazine that a guy built a shelf layout, no loop, and wondered how he did that. Since the track doesn't make a complete circuit. My guess is that under the layout you would have to attach wires from one end to the other. I, mysef, have never wired a track, well except for my first train set the little oval. For something bigger I wonder if it would need to be in stages and to run 2 trains at once, I'm clueless. Guess my first description was a little misleading.

 

[UP2CSX]

Doug, OK, I think I understand now, Electricity flows in both directions from the point of connection. You can connect the power leads to the ends or the middle of a shelf layout and the power will flow until it meets enough resistance to stop, which is usually the end of the track. The track doesn't have to make a complete closed circuit like a loop to have a train run. There are many point to point layouts where the ends never touch. Placing the locomotive on the track completes the circuit and then it's up to the power pack or DCC controller to decide what happens next. On bigger layouts using DCC, all you need to worry about is having enough wire feeding the track so you have constant voltage. This means every three to four feet in practice. If the layout is DC and you want to run two or more trains, you'd have to divide all the tracks into blocks and have a control panel and multiple power packs. It's the way it was done for decades and it's way more complicated than you even want to understand. Just remember that with DCC, as long as the track has power, you can have multiple locomotives moving on different or even the same tracks with nothing but the minimum of two power feeders to some spot on the track.

 

[doug1980]

Oh....Thanks for clearing that up for me. Sounds like DCC is the only way to go. I like simplicity.

 

[Selector]

In fact, in order for the electrons available in the rails to do their work at all, the motor in the engine actually does close the loop...it provides a bridge between the two rails with their different polarities. Once you power the track, even with a micro-volt, in DC, the motor is sensing some potential and wants to turn...except that such a teensy voltage is not sending enough electrons through the motor to overcome all the various forms of friction in the locomotive, and also in anything coupled to it that it is meant to tow.

If you want the engine to move at all, particularly with some cars attached, you must up the voltage (many more electrons), and the motor will begin to overcome all resistances and frictions, and you can see the locomotive and consist behind it begin to get underway.

In DCC, the voltage is always at maximum to the tracks, and it isn't a DC voltage. It is a special, digital, AC current that is supplied...at or above 14 volts. Why doesn't the locomotive lurch into motion and dash around the layout? Because the decoder hasn't passed on any voltage to the DC motor in the engine. With DCC, you must tell the little brain to make the engine move, and not only that, how to move...slowly accelerating, quickly accelerating, slowly decelerating, quickly decelerating...and the motor obeys the instructions that it gets from the decoder, instructions that are merely metered DC current sent in very high frequency pulses.

It is this system of delivery of metered voltage to the motor that allows the DCC engine to operate like it could not possibly on a DC track system. On DC tracks, no matter which way you make an engine face on the track, even two of them back to back, they will both move in the same direction as you crank up voltage on your DC transformer. DCC allows each engine to do what you tell the decoder to do, and that could be them chasing each other or actually moving apart on the same rails.

For me, the choice is very clear, and very easy.

-Crandell

 

[doug1980]

So what it sounds like to me is with DCC you will get more realistic operation. And as long as my loco's are DCC compatible it's easier to wire up than DC.

 

[Selector]

We have a saying in the hobby that with DC you have to run the layout since you are likely to have blocks energized via toggle switches. It's the only way to run trains around a whole layout when you have more than one and want them to behave differently...with more control. The other part of the saying is that with DCC, you get to run the trains.

So, you are correct...DCC is more realistic if not having to keep track of where trains are headed, and flipping switches to enable their continued movement is not particularly appealing to you. In fairness, that aspect, which could be construed as blocking or lining the route (in DC) is not unlike the real world of trains, and it does appeal to those who hold steadfastly to DC operations. I prefer, as do those who master DCC, to just use my throttle to control trains' movements as if I were the engineer. As an engineer, I shouldn't have to "dismount" and throw a block switch allowing me to proceed. That is why it is said that in DC you have to run the layout.

Your engines are not going to be DCC compatible unless a decoder is installed in them correctly and safely. It's an either/or thing...it has a decoder and is DCC compatible, or it is not. Also, not all engines are wired the same way, nor constructed the same way when meant for DC operations. Some are designed so that you must physically isolate the motor from the metal frame of the engine before you can install a decoder...otherwise the magic smoke will puff out of the decoder upon power-up and you have a non-operating, and now non-DC, engine on your hands. The decoder must get power directly from the rails, including the DCC signal imprinted on the power supplied to the rails at full voltage, and it interprets your own inputs via the throttle and sends the correct voltage in DC to the motor...which is always DC...here in N. America. German Marklin engines are AC, I believe, and need special control systems.

 

[UP2CSX]

Dang, Crandell, you sure are good at explaining all this electrical stuff. Doug, as Crandell so clearly wrote, DCC allows you to have a lot more fun running trains. The engines will run better and you'll have the opportunity to add sound, which opens up a whole new world in model railroading. I'm glad I got back in the hobby as DCC was maturing. Having built several DC, block controlled layouts, just the thought of all those wires and toggles switches makes me nauseous.

 

[Selector]

Thanks, Jim. I used to be a bit heavy on detail, being a personality that enjoyed the nitty gritty. I found, though, and often via feedback from observers to some of my seminars and teaching in other subjects, that I got too bogged down in intricacies and not enough on the "So what should this mean for my purposes first thing tomorrow morning?" I was cautioned to spare those who hadn't the same interest for the details, and to get to the nub. Took a while, too.

-Crandell

 

[doug1980]

Crandell thank you for the great explanations. It makes a little more sense to me now. Considering my layout will be fairly small and only a point to point shelf layout some of the elaborate funtions I will not need. However it is all good to know and I appreciate all the help.