Booster?

Hi all, I'm novDCC novice, but this has got me stumped and I just can't find specific info on this:

I'm finally building a big enough layout that a 'booster' is probably in order. I'd end up with runs of 60-90' otherwise.

But I can't find a bloody thing with specifics on equipment (I run a Lenz system, but could infer from others I imagine), how to wire it up, etc. Plenty of generic descriptions, but no "this is what you need and this is how to hook it up. I don't get it... If I wire two completely separate districts with power supplies, DCC encoder, etc., then I have two layouts... But I can't find a 'box' that's a 'slave' encoder or similar, nor a diagram or instructions on how to do it.

Short version - I believe I 'get' the concept, but the execution is not coming to me...

Kris
 
Hello Kris. The size of your layout, whether it is 60'x 90' or 600'x 900' does not determine whether you need a booster or not. Whether you need a booster will depend on the number of locomotives you are going to run at one time on the layout and where your command station/booster is located on the layout.

For information with respect to the number of locomotives, visit this page on my website.
http://www.railwaybob.com/Modules/WhatIsDCC/DCCWhatIs01.htm

On a large layout, the location of your command station/booster on your layout and the size or gauge of wire on your track power buss and feeder wires will determine whether you need to add a booster.

For the location, assume you have a point-to-point layout. As you run a track power buss around the layout to feed the tracks with power, there is a drop in the voltage of the wire. This drop is small on small layouts but can be large on larger layouts. If you were to locate your command station/ booster in the middle of your layout, then the maximum length of your track power buss will be about 45' (45' to the west, 45 ' to the east equals 90'). A length of 45' should not result in a significant drop in power if you are using a heavy gauge wire such as 14 AWG stranded wire.

However, if you place your command station at one end of your layout, the maximum length of your track power buss will be 90'. In this case, you would probably want to add a booster.

Which brings us to the thickness or wire gauge of the wire you are using to bring the power to the tracks and how frequently you bring the power to the tracks (ie the number and location of your track feeder wires. If you are using telephone wire (24 AWG wire), the voltage drop is quite dramatic as you go out each yard. However, if you use 14 AWG wire, the voltage drop isn't as dramatic. Similarly, if you have track feeds every 10' - 12', there is quite a drop in voltage along the length of track that is fed by each track feed. However, if you have track feeds every 3' - 4', the voltage drop isn't as dramatic.

So, if you are using telephone wire to bring the power to a 90' layout, you will definitely need a couple of boosters to boost up the voltage. The solution in this case would be to use some heavy gauge wire - 14 AWG wire as a minimum. (Remember that as the AWG number decreases, the wire thickness increases. That is, 14 awg wire is thicker than 24 AWG wire.) For a discussion on wire gauge and voltage drop, visit this page on my website.
http://www.railwaybob.com/Modules/TrackBuss/TrackBuss01.html

The shape and format of a booster will depend upon the manufacturer of your command station/booster and whether it is compatible with the other boosters that are made by manufacturers. In your case, you are using a Lenz system so Lenz probably has a booster that can be added to their system. I'm not at all familiar with Lenz so I can't help you out specifically.

In the case of Digitrax, to add a booster to the system, you simply buy another command station/ booster and configure it as a booster. For example, I have a Digitrax DCS100 command station/ booster. I could purchase another DCS100 command station/ booster and configure it as a booster, or I could purchase their lower priced DBS150 command station booster and configure it as a booster. Or, I could purchase a lower-priced booster from another manufacturer if it was compatible with my DCS100 command station/ booster.

Perhaps some other people who use Lenz could help out here with the specifics.

Bob M.
 
Hello Kris. Now, I didn't completely answer your question. One unit is designated as the command station but it also serves double-duty as a booster. All a booster does is take the signals generated by the command station and pumps the signals out onto the track at a voltage which will also allow us to run the trains.

The signals (stop, go, speed up, slow down, headlights on off, ring the bell, blow the horn, etc) are generated in the command station. The command station feeds the signal to the boosters. So, to connect another booster to the command station usually only involves running a telephone cable from the command station (which also serves as a booster) to the other booster. Usually, the other booster has to be properly configured and have its own power supply.
 
Thanks, Bob. Great info, especially the 2nd post - exactly what I was confused about. I get it now.

Running locos is absolutely NOT the constraint. I can't envision running more than about 10 at once - and that very rarely if I had several buddies over. I'd venture to say that 90% of the time I'll run 5 or fewer simultaneously. If my locos pull 0.5 amps each, I might be pushing it at 10... I'm content to adopt a wait-and-see on that one: wire to accommodate a booster, but see how we do with one for now.

As for distance constraints: If I place my booster to minimize longest run, it'll be about 60' from booster to the most distant place on any part of the bus. (In other words, a bus running rully around the layout would be 120'). I plan to run the bus using 12 ga. wire, twisted to avoid cross-talk. I'll feed the tracks every 3' or so 9which means in general one feed to every piece of flextrack). I'm gathering this is NOT likely to mean a second booster is needed, but certainly open to feedback from those with direct experience.

On my previous layout, the bus was only 25' long, and had feeders every 8' of track. no problems there, but we're talking a 10x14 L-shape versus a 20x30 around-the-walls, so a world of difference.

I'll go check and see how Lenz deals with boosters, just in case, but any feedback from the Lenzies of the world remains welcome.
 
Hello Kris. Remember that, if you do your wiring in the form of a 2-wire buss, you can always cut that 2-wire buss and hook one part into your command station/booster and the other part into that new booster. Or you could just as easily cut it into three sections and add a third booster.

The secret here is to do your wiring in such a way that you can always adapt the buss for future command stations.

The command station and boosters can then be connected together so that the command station can pass the signals on to the boosters which simply amplify the signal and put the signals out on the track at a higher voltage.

I briefly looked at the Lenz page on their command stations and boosters.
http://www.lenz.com/products/xpressnet/index.htm then click on LZV100 which is a pdf file.

In the case of Lenz, it would appear that the LZV100 is a combination command station/booster whereas something like the LV101 is a booster.. If you take a look at the manual on the LZV100, Page 8 shows a schematic of how an LZV 100 connects to an LV101. What is not so obvious is the gap in the tracks between the two power districts (the orange band of colour in the tracks.

If you go on down to Chapter 8 on Page 20, there is a detailed diagram of how an LV101 booster is connected to the LZV100, pin-by-pin. Again what is not so obvious is the gap in the tracks between the power districts.
 
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