AC vs DC?

[TheMacDiesel]

Hi all,

 I have another Greenhorn question for you...

 I'm starting my new outdoor layout with about 250' of mainline track (very simple right now, one big loop around the yard with a small switch yard on one long straight-away.)  I have a 5A LGB transformer (AC output) and some older LGB locos that I inherited, and am planning to upgrade to a 10+ A system, likely with DCC.

 When I move to a bigger power supply do I need a DC supply for running USA Trains and Aristo motive power?  Will a DC supply be compatible with LGB engines?

 Also, one wiring question...  I read a lot on the forum about a "feeder line."  Am I correct in interpretting that this is the "+" side of the power on one long, heavy-gauge (#10) wire with short runs of lighter gauge (#12 or #14) wire connected to it and running to the track?

Thanks!

--Sean-- 

[cacole]

As near as I know, all G-scale locomotives run on DC power.  Only the old Lionel and American Flyer O scale and S scale trains used AC.

Feeder lines are exactly what you have surmised them to be.  A heavy gauge wire running to several points or parallel to your track, and feeder wires connected to the track at various points.  The only thing wrong with what you have written is that both + and - wires need to be fed to the track at each point.  You can get special rail clamps that have terminals for the feeder wires. 

With DC or DCC control, you must watch out for reverse loops and places where the track might turn back on itself.  These can present wiring problems because of polarity issues.

One way I advise people to keep their wiring straight is to imagine yourself as the engineer sitting in the right-hand seat of the locomotive going around the track.  The positive wire always connects to the same rail as you go around the layout and connect your wiring.

 

[TheMacDiesel]

Thanks cacole...  I remember reversing loops from my HO days in the waaaay distant past, so I'm trying my best to avoid them completely... :-)

 Thanks for clarifying the feeder question...

 I'm still confused about the AC/DC issue, since there are a number of power supplies that specifically talk about AC output ratings.  I'll keep digging.

 --SM--

 

[altterrain]

Sean,

Does your power pack only have one set of outputs? Usually there is an AC set just for running accessories like scenery lights but there should be a output set for the variable DC output for track power.

For your track plan I would suggest a dogbone to make for easier wiring and operation but there are several ways for wiring a reversing loop - http://www.girr.org/girr/tips/tips3/reversing_tips.html

For your power feeds I would suggest 3 for the length of track you have. Most use low voltage landscape light wire as it is design for outdoor underground use. I use 16 gauge for the short lengths and 14 ga. for the longer stretches (over 30 ft.).

Good luck with the DCC. I have yet to see a system actually work for any length of time.

Have fun, Brian 

 

[kstrong]

With proper joints between the rails (solder, rail clamps, or screws) the need for feeder wires is significantly reduced. Why? Because the rails have a larger cross-section than the feeders, therefore less resistance per fool than the feeder wires themselves. Essentially, you'd be using the rails to send power to the feeder wires. Most folks who run track power nowdays swear by rail clamps (Hillman, Split-Jaw, and a few new offerings). If I were doing track power, that's the route I'd take. Their biggest advantage over the other methods is that they're non-destructive. If you want to change something, you simply remove the clamp, make your change, then clamp everything back in place.

Later,

K

[TheMacDiesel]

Hi kstrong,

 Thanks for both of your posts.

 Yes -- I am planning to use SplitJaw clamps and running feeders every 20'.

--Sean-- 

[Anonymous]

You can't go wrong using clamps and feeders. Don't forget, the track will corrode, being exposed to the elements and if you don't clean the track regularily, power will still flow via the feeders. What material are you using for track. Brass is the best as it's resistance is less than aluminum or SS. Aluminum corrodes quicker than the others, so cleaning is a constant chore.

[Camaro1967]

Kevin's answer is exactly right. 

If you would use stainless track with split jaw or Hillman clamps, you would not need feeders at all. I have over 400 ft of stainless track, with no feeders, Hillman clamps on every joint, and no drop in voltage anywhere. 

Paul

[piercedan]

Almost all of the garden railroads are DC powered.

 

New Bright animated trains are different and must use the power pack that comes with them.

 

Also, most trains run at 18 volts, newer Electronic ones need 22-24 volts, but there are some that have 12 volt motors.  The Disney casey is one of these that is 12 volts. 

[Anonymous]

You can't go wrong using clamps and feeders. Don't forget, the track will corrode, being exposed to the elements and if you don't clean the track regularily, power will still flow via the feeders.

 

I'm curious to understand why you say that.  If the track is not clean, power will not flow from the rails to the engine.  It doesn't seem like the feeders will help this problem.  Am I misunderstanding something?

 Thanks,

Mark 

 

[altterrain]

Ronald (DD1) said a couple of things I would disagree with. The fact that brass is best it a matter of opinion, one that I disagree with. I have seen no corrosion on mine and track cleaning is a weekly run around with the track cleaning car to get the dirt off. I have seen postings of minor rusting on stainless track but it has been minor and only on the sides of the rail. A friend of mine, who sells and installs battery/RC systems, always comments how well my locos run on my track. I use, at most, 25% rail clamps, the rest stock rail joiners and feeders about every 40 feet.

I have yet to see anyone use aluminum track with track power. It seems to be the millieu of battery power, exclusively. Yes, dirty track will impede power flow no matter how many feeders you have. Multiple feeders can though reinforce voltage flow where you may have poor rail to rail connections cause by dirt or corrosion, even with rail clamps. A club member uses a bit of electrolytic grease on his brass rail clamps with brass track to prevent this.

-Brian 

[Rex in Pinetop]

I don't think stainless can rust but it certainly can get dirty.  Painting it will also impact the conductivity with the wheels if you don't wipe the paint off the top of the rails. 

Rex

Battery power loves dirty track as long as the wheels will roll!

[altterrain]

Stainless can rust, especially when enacted upon by chlorine, salt or other corrosive agents. I'm sure if you rummage around in your silverware drawer you might find a piece with a spot of rust. The only folks I know of that have seen any rust on their track are in coastal climates.

http://www.aristocraft.com/vbulletinforums/showthread.php?t=10049

-Brian 

[Anonymous]

You are correct in what you say. To me it's just a little extra insurance. I have been using track power, but I am going to switch over to battery power and radio control. I won't have to worry about dirty rails anymore.