Wiring Help!

[Anonymous]

I need some sound advice from you guys on wiring my track with feeders. I have read MR's "Easy Model Railroad Wiring" and numerous other articles but am still stuck on the following: With only two connections to my main power pack for variable DC, how can I wire numerous feeders to my track using terminal strips? For example, using a 6 or 10 screw terminal strip, how can I make all the feeder wires I attach to this terminal strip active when I only have two wires available and leading out from my power pack (a model Tech II 2500).

I could run bus wires under my layout, and I know how to solder the feeders to that, but I have read that this is more work and that terminal strips are somewhat better in that they organize the wires neater. But again I don't know where to place my two wires from the power pack to operate the many additional wires and feeders. (I do have three additional smaller power packs, but I was going to use them all for my other AC features)

My track is code 83, no blocks, DCC, and all my turnouts are live (Atlas)

Please advise and thanks for any suggestions.
John in Apple Valley

[Sperandeo]

Hi John,

Thank you for reading my book, "Easy Model Railroad Wiring," but I'm a little confused by your question. Are you using DCC? If so, you definitely do not want to connect the variable DC terminals of a power pack to your track.

If that's not really what you meant, the solution to your terminal strip question is shown on page 106 (Second Edition), in fig. 10-18, "Bridging Terminals." You can install these bridge connectors to tie togerther as many terminals as necessary along one side of the terminal strip, and make your track feeder connections on the other side. You could also do the same thing with bare bus wire, but the bridge connectors are neater and the slotted ones can be installed very quickly.

Or if the layout won't have any control blocks, you could use the bus-and-feeder method you alluded to. The bus-and-feeder wiring would be simpler and faster, but the terminal strip approach would make it easier to add blocks in the future if you ever decide to do so. You'll have to decide which is best for you.

If you do go with the bus and feeders, I recommend IDC or "suitcase" connectors for making the connections to the bus, as shown on pages 100 and 101. These are faster and neater than stripping, soldering, and taping, and I use a lot of them on my own layout.

Good luck with your railroad,

Andy

Andy Sperandeo
MODEL RAILROADER Magazine

[Anonymous]

Andy, Thanks for the reply. I plan on using DCC but now I am really confused. Why won't I use my power pack and the two variable DC outlets in the back to hook up electrical power to the rails?

I will need current in the rails some how. What will I need to do this? I have not yet purchased my DCC outfit, but plan to as soon as I have wired my track. As I mentioned, I have 4 power packs, two of which are smaller and I was going to use them for the AC accessaries.

John

[Anonymous]

John,

When you use DCC the track is powered by constant voltage supplies. The DCC controler sends a digital signal through the track. Each engine picks up the signal and decodes it. If the message is meant for that particular engine, the engine executes the command (slow down/speed up/turn on sound/...) otherwise it ignores the command.

You may want to hook up your stuff using a single block for the whole layout right now (assuming it is small enough). You will be able to run one cab with two-rail DC control for now. Then you can do some more research on DCC.

Good Luck. - Ed

[Anonymous]

Ed,

When you say constant voltage supply, do you mean direct DC current? Is the DC controller powered by my power pack? I think I understand about hooking up to one big block, although my layout is approx 9 feet x 8 feet.

Since I want to run trains now and don't have DCC yet, how do I connect my two outlet DC variable connector from my power pack to supply all the feeder wires to the rails? Thanks.

John

[Anonymous]

John,

I don't use DCC but I think the supplies are constant votlage DC supplies, definately not variable DC. Some MRC power packs have three sets of output; variable DC, constant DC and AC accessory power. The accessory power powers the lights and some types of switch machines. The variable DC powers traditional two rail cab wiring and the constant DC power can be used for a second cab control. I would think that the constant DC could be used for a supply on a DCC controled railroad.

To connect your layout to the power using the Tech II 2500 throttle, I would get two terminal strips (the black kind from Radio Shack). Place jumper wires along one edge connecting all the screws on one side together with wires. Do this to both terminal strips. Connect this side (jumper side) of the terminal strip to one of the variable DC outputs on your throttle and connect the other variable DC output to the jumper side of the other terminal strip. Now each terminal strip is attached to one of the power pack outputs. Next you look at the layout and assuming it is some kind of oval, waterwings or whatever, you have an inside rail and an outside rail. Connect the inside rail to one terminal strip all the way around your layout. Run a (jumper) wire from each connection to the same terminal strip and connect the wire to a position on the side opposite the jumper side. Then connect the outside rail to the other terminal strip in the same manner. Now the inside rail is connected to one variable DC output of the power pack and the outside rail is connected to the other variable DC output of the power pack.

If you don't have any "reversing sections" then this is all you will have to do to run one cab on you layout with DC two rail wiring. Later, when you have learned how to hook up DCC, you will find it easier with the terminal strips already connected as I have suggested.

The lights and atlas switch machines run off the AC accessory terminals. I haven't done so on my layout yet, but I recommend you buy a 'surge' circuit like the 'Snapper' advertised in MR from time to time. The switch machines are connected to the output of the Snapper and that will improve the operation of your switch machines. Don't do this if you are not using twin coil switch machines like those produced by Atlas. I think this is discussed in Andy's book but I may have read about it in another book called Electronics Projects for Model Railroads or something like that. I could build the one in the book myself, but I wouldn't recommend anyone do it unless you think you are comfortable with all the terminology in the book.

Good Luck - Ed

[Anonymous]

Ed,

I have saved your response for future reference. I am also going to check with several DCC manufacturers just to verify the proper voltage, but then will go ahead and begin to add feeders and a bus line under my layout. Thanks for the information and I will let you know what I find out. Good luck to you.

John

[Sperandeo]

Hello John,

Sorry I wasn't able to follow up with you right away. You can connect the variable DC terminals of your power pack to the feeder bus and run a train with the power pack now, but when you get your DCC system you'll have to disconnect the variable DC and connect the DCC output to the track.

The current on the track with DCC is actually a square wave alternating current (12-14 volts AC) that both supplies power and carries the control signals. However, the motor in a decoder-equipped locomotive only receives the output from the decoder, which is generally in the form of DC pulses. The motor is no longer directly connected to the track.

With some DCC systems, such as Lenz, you'll be able to use your original power pack as a power supply for the DCC components. But those variable DC terminals cannot be connected to the track or the feeder bus when you're using DCC.

For a very basic explanation, see "DCC: what it is and what it does" in the November 1997 MODEL RAILROADER, pages 88-89. (Back issues and photocopies of articles from out-of-print back issues are available from [e-mail].)

Best wishes,

Andy Sperandeo
MODEL RAILROADER Magazine

[Anonymous]

Andy,

That is the information I have been waiting to confirm. The Tech II power pack I have has both variable DC and "fixed DC", which is, I assume, what you are referring to as power I can use with some DCC equipment (ie: to power the booster and command station).

In the meantime, I will hook up the "variable DC" to my bus lines and feeders and run trains until I have DCC purchased and decoders installed.

I do have the DCC article you refer to from the 1997 MR and in fact save all pertanent articles from MR just for this reason. Thanks again for getting back to me.

John

[Anonymous]

John:

If you are planning on converting to DCC, make sure that the wire you use is thick enough. I suggest that you check out the website wiringfordcc.com. It has a lot of practical suggestions.

[Anonymous]

Jim,

You are correct, the wire gauge is important. Andy Sperandeo of MR suggests at minimum 14 gauge and even 12 gauge for the bus wires. I have begun to install 20 gauge for the feeders and purchased a 100 foot role of 14 gauge for the bus lines. I will also check out the website you suggested. Thanks.

John

[Anonymous]

If it's not to late let me say that you have a lot of terminal strips to get. But I just use leftover peices of NS track. Solder two feeder wires from your powerpack to the rail and have the other wires coming off the rail. It works great and saved me around 100 bucks.

[Anonymous]

Excellant idea! Why didn't I think of that? Thank you.

[Sperandeo]

Hi John,

One of the new items at last week's Chicago hobby show was the Zephyr DCC system by Digitrax. This unit has one built-in throttle and capacity for expansion using Digitrax walkaround throttles, either tethered or wireless. What's really new about the Zephyr, though, is that it has two "ports" where you can connect any DC powerpack and use it as an additional DCC throttle.

You'd still disconnect the variable DC from the rails (or from the bus), but now you could connect it to the Zephyr and continue to use the power pack you started with. The Zephyr is shown in the Digitrax ad in the October MR (page 110), although the ad doesn't really explain this new feature. You could look for more information on the digitrax Web site, www.digitrax.com.

So long,

Andy

Andy Sperandeo
MODEL RAILROADER Magazine

[Anonymous]

Andy,

Thanks for this information. I will check it out. I do, however, still have questions as to how to run my bus lines and connect the dozen or so feeders to them in the mean time. Is there someone I can talk to direct and explain what I am trying to do?

Let me know, and thanks.

John

[Sperandeo]

Hi John,

You're welcome to e-mail me directly at [e-mail].

So long,

Andy

[Anonymous]

Andy,

That would be a big help. Let me compose a very detailed note with my electrical questions and then I will send on over to you. Many thanks in advance.

John in Apple Valley