What is the disadvantage of running a single large booster with enough reserve capability and separate breakers for each power district vs running a number of smaller boosters and the same number of breakers (one for each power district)? Example; 10 amp total requirement, 10 power districts with a CB for each district. One 10 amp booster (assuming there is such a thing) vs five, two amp boosters. 10 amps capacity either way, same number of districts, each with a breaker. Is there a issue for block occupancy?
Bruce,
A few questions for you:
I'd also be curious to know how you came up with the 20A need. Or, was that just an arbitrary example?
Tom
https://tstage9.wixsite.com/nyc-modeling
Time...It marches on...without ever turning around to see if anyone is even keeping in step.
I don't believe a 20 amp booster is made. If it was, finding a power supply that would handle its full rated load would be hard. This much power gets into the arc-welding realm if a short occurs.
Most boosters I am familiar with are rated 5 amps. Distributing these around the layout, keeping the bus wire runs short, is probably the best way to go. Usually you would want to keep bus wires about 30 feet or less in length from each booster. The command cables can be much longer, without degradation of signal, and things running goofy.
Mike WSOR engineer | HO scale since 1988 | Visit our club www.WCGandyDancers.com
Depends.
How much power do you really need? For most applications, a 5A booster and a circuit breaker setup would be good, and if current demand gets too high, a second booster could be added into the system.
We'll just have to assume you are talking about HO. Five amps seems to be plenty for most setups. Again, if more current is needed, a second booster would be in order. You can always locate them near the section they will serve as well.
How many locomotives do you plan to run at the same time, and what scale are they? That would help answer the question.
I'd sure like to see pictures of that layout that requires 20 amps.
Dave
Lackawanna Route of the Phoebe Snow
Guys, It was just an example. Sheesh!
I'm running seven unit consists, with a mid train & rear end helpers on a four track 2.2% grade in Pennsylvania.
( I edited the 1st post.)
Anyway, to answer the questions, N scale, double track mainline, receiving & hump yard, freight & passenger (limited pass. operation), fairly long trains. IOW's a ML operating layout.
Is there a a issue with block occupancy with using just one booster assuming everything else remains the same?
As long as the total current available is the same (and adequate) either way, is there any problem(s) just using one supply?
We run a total of 20 amps on our modular layout, three 5A booster on the main and one for the engine facility.
10A boosters are made. The advantage of multiple smaller boosters would be for some redundancy, if one of those fails you could probbaly bridge power from an adjacent section temporarily. If a single 10A booster dies, the whole layout is down. There's really no issue for block detection if you pay attention to the wiring. It exactly the same regardless if the block detection is downstream from multiple circuit breakers all fed by one monster booster or downstream of a dozen small boosters.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
If your layout is physically large, smaller boosters would allow you to distribute your power more efficiently. Instead of a single large central booster powering a bus 100 feet away, you could spread the boosters out have them physically close to the bus, which would give you less loss getting to the bus wires under the tracks.
On the other hand, you then have to worry about maintaining a clean signal from your base statiion to the boosters for your control information.
It takes an iron man to play with a toy iron horse.
"There's really no issue for block detection if you pay attention to the wiring. It exactly the same regardless if the block detection is downstream from multiple circuit breakers all fed by one monster booster or downstream of a dozen small boosters."
That is basically what I wanted to know. Usually when a shortcut (of sorts) is made, there is some price. I do understand the whole layout would go down if the single PS would fail.
Anyone else disagree??
videobruce "There's really no issue for block detection if you pay attention to the wiring. It exactly the same regardless if the block detection is downstream from multiple circuit breakers all fed by one monster booster or downstream of a dozen small boosters." That is basically what I wanted to know. Usually when a shortcut (of sorts) is made, there is some price. I do understand the whole layout would go down if the single PS would fail. Anyone else disagree??
I will have to disagree. Both Logic Rail and W S Ataras signal system need 'optical isolation' between booster districts. If you have circuit breaker districts off of a booster, there is no issue.
The advantage 'signal wise' of a single large booster with circuit breakers is no need for the optical isolation. Also the cost of a single large booster is usually less that multiple small boosters Multiple small booster have the advantage of redundancy.
Our club has 24 amps of booster track power:
8 amp command station
8 amp command station(in booster mode)
8 amp booster
We have a pair of 20 amp Digitrax power supplies that provide the power to the command stations/booster.
At home, I have a 5 amp command station and a 5 amp booster, with 4 power districts(2 off of the command station and 2 off of the booster).
Jim
Modeling BNSF and Milwaukee Road in SW Wisconsin
Personally, before you go wild ordering hundreds of dollars of electronics, I'd like to ask if they are even needed for your layout? If you only have a bedroom-sized layout, and only expect single train/single-operator action on your railroad, multiple boosters and even multiple circuit breakers are overkill.
OTOH, if you have many sound engines, that can change the power requirements extensively if you plan to have them all powered all the time (a kill toggle or two for an engine facility can be a cheap fix). But if you don't, adding multiple boosters are a needless expense. Even if you do have sound engines, it's not always necessary to provide a couple dozen amps of power.
For example, I have a 25' x 50' HO layout that currently has 2 QSI's, 1 Tsunami, and 1 LokSound (plus another 20 or so soundless engines). I have just my 2.5 amp Digitrax Zephyr and no circuit breakers running the whole shebang, and I have had up to 4 operators running a total of 4 trains at the same time. If I want to add detection, it's the same no matter the power needs. It's a lot more wire, of course, but that's expected.
Paul A. Cutler III
I saw your question on the N scale forum. Can I assume this is N Scale? The trains you have listed should operate just fine with a 3 amp Zephyr extra or similar size booster. If you really want to break the layout into power sub districts go with a 5 amp unit and add breakers to create subdistricts. If the layout is super large with bus runs over 35 to 40 feet each way from the booster, you might need to think about adding a second booster. Might is the key word.
Martin Myers
Well there's two signal systems I wouldn't use with DCC then.. they obviously have some common conenction between blocks that would pass the track signal for some unknown reason, requiring the optoisolated boosters. Very odd. Can't be just because the detector passes track current, the Digitrax BDL168 does that and you can splif the 16 detection sections acrtoss more than one booster without it being optically isolated - unless you use common rail wiring, which is just bad form all around. Other detectors like Team Digital, NCE, and RR CirKits aren;t even in the track power circuit, using current sense transformers, whcih is an overall better way than diode drop anyway. Sicne the Atlas signal system at least can use other detector inputs, I can;t see it being a problem with multiple boosters and no optical isolation if it was fed via somethign liek the NCE BD20. The rest of the signal system has no reason to connect to track power, and using the transformer type detector keeps it isolated entirely from track power.
Actually, Logic Rail is even recommending NOT to use their BlockMaster - says right on their site to contact them before ordering as they may recommend a better more state of the art option from someone else. And Atlas seems to only have a block detector for analog DC - which, being a Twin-T ro similar based ont he wiring diagram, would need optically isolated boosters, however alternate block detectors would work, and be better all around for DCC use.
Bottom line - systems designed for DCC, there's no difference in wiring, 1 booster with breakers or many boosters.
jrbernierI will have to disagree. Both Logic Rail and W S Ataras signal system need 'optical isolation' between booster districts. Also the cost of a single large booster is usually less that multiple small boosters Multiple small booster have the advantage of redundancy.
I understand about the 'redundancy' part.
Yes, this is N scale (roughly 10'x20' U shaped layout).
So much for not having 20 amp power supplies available.
rrinker; There are so many unanswered questions even after reading three different books on DCC including, what appears to be the most recent (2010): DCC Projects & Apps. Vol 2
While we are on the subject, is there any better reading (and recent)?
With a 10 x 20 layout and N-scale, you could get by with your DCC system and one 5A booster; more than enough for what you'll need. How you divide the power up into districts is then contingent on how many yards, sidings, staging, etc. you have and the maximum number of locomotives you'll have in any one district.
Hi!
I've always believed more is better and have a reputation for overkill in whatever construction I do.
So when I was looking to convert to DCC, I gave serious thought of buying the 20 amp booster put out by Digitrax. The folks on this Forum convinced me otherwise, given that my layout was "only" 11x15 two level with lots of locos in place.
I'm all up and running now, and ended up with two 5 amp boosters, which is way more than adequate. I very likely could have gotten away with one 5 amp power source, but wanted two.
Having been in HO DC operation for decades, I was used to locos eating up the amps. But today's locos require only a fraction of power, thus allowing a 5 amp system to take care of a very large layout. Actually, I think that the emphasis on the number of well placed feeders and clean track is much more important in the scheme of thing............
Sorry for the disjointed writing, the coffee has yet to kick in................
ENJOY !
Mobilman44
Living in southeast Texas, formerly modeling the "postwar" Santa Fe and Illinois Central
A 'standrd' non optically-isolated booster generally uses a low power copy of the track signal to feed teh booster, which really acts like an amplifier to generate a signal matchign the input, only with some larger amperage (say 5 amps for many common systems). All is well and good if at the track joints between sectiosn powered by different boosters, you gap both rails. No problems (assumign you hook the boosters both up the same way). Now, if you wire your layotu the old Atlas way, which is to say one rail is common over the entire layotu, and you only gap one rail between sectiosn powered by different boosters, it's entirely possibel to create a situation where double the output voltage appears across the gap. Not good for decoders. Optically isolated boosters use that same low power (or even tap off the actual track power) as the input, but rather than that being coupled to the amplifier portion, there is a device calles an optoisolator there. Basical;ly, an LED and a phototransistor in a chip. The only connection between the input terminals and the input of the amplifier portion is the light from the LED, there is no actual circuit connection between the two. This prevents any 'sneak path' for voltage to get where it isn't wanted.
SO now you have the 'big' blocks for power distribution. Your detection blocks for signallign will generally be much smaller distances, multiple signal blocks inside one power block. Some signal detectors require a common connection between all detectors, effectively makign a common rail across all power blocks - optically isolated boosters needed. Others do not work that way, each detector is compeltely independent of any other, and in fact, the tranformer type I mentioned aren't electrically connected to the track power at all. The track feeder passes through a small coil, which induces a voltage in the coil when current is passing through - liek when a train with a motor, lights, or resistor wheelsets is in the detection block. The signal system then acts on this induced voltage. No actual electrical circuit between the track power and the singal system, this is as it should be.
SO one rail within a given power block needs to be gapped where appropriate for the signals. All feeders (unless your blocks are REALLY small, you'll want more than one set of feeders! Every 3-6 feet is a good rule of thumb, signals or no signals) for a given detection section need to pass through that detector. An easy way with the transformer detectors, at least those that mount remotely like the RR-CirKits ones, is to get two terminal strips and put them a few inces apart, one side is the input power fromt he booster, the other is where the feeder(s) connect. A short length of wire conencts opposing terminals on the two strips, each with one of the transformers threaded on it.
WHat you end up with is that in a given power section, you have common rail wiring for the detectors. BETWEEN power sections, you gap both rails, no common, no problem. The common rail withon a single booster's powered area is not a problem, the only time common rail is a problem is between sections powered with different boosters.
I thought you had to isolate both rails?
Only between power sections coming from either boosters or circuit breakers (and even then, some circuit breakers only open one side of the circuit anyway).
FOr signals, no, they detectors only need to sense a current flow, you do not need both rails gapped for that.