You need a second booster to accomplish what I drew.
–Randy
I understand that. My only point was that the current booster is integral to the command station, so I need to figure a way to install that second booster and keep the two some distance apart.
Rich
Rich,
The second booster needs only two connection to the Command Station/First booster.
A. A control bus connection (looks like a phone cord, but may be “special”)
B. the grounding wire that runs from one case to the other. I put the spade at each end of it under one of the screws holding the case together on the two boxes. There is no internal connection, as the cases is already grounded internally.
Mine just happen to sit about a foot apart, but 80’ is no problem once you have the wiring long enough. Maybe the connections don’t have to be that long and can take a shortcut, though, since your layout loops back around?
On the front of your command station, there are those jacks labeled “control bus” - that’s how you connect to additional boosters. Different than the cab bus, where you plug throttles in.
The long distance isn;t a problem, because the load placed on those lines by the booster to ‘read’ the signal is miniscule, plus it’s a differential signal, which means the electronics int eh booster looks at the difference between the two wires and not the absolute voltage. This if there is say a 1V drop, both the ‘high’ and the ‘low’ will drop by 1V - the difference between them will be the same. It’s also fairly immune to interference, say the wire gets run parallel to an AC power line for a segment - there will be an induced voltage on the wires from the parallel conductors, but both the ‘high’ and the ‘low’ will see an increase - again the difference between them remains the same.
OK more technical than you wanted, but that’s another part of why you can run a thin phone cord 80 some feet and drive another booster and it’s better than running 80 feet of bus wire.
Pages 21-23 of the current PH-Pro manual mention the control bus and adding more boosters. Not a lot of info and no picture, boo!
–Randy
Rich.
I am a firm believer in Alan Gartners site. He even has scope traces that show ringing on the signal part. Also twisting long buss runs has been proven (seen it myself) to limit outside interferance from strong wirless signals. I know the debate about the track not being twisted and all. First the rail is nickle silver/ tin based metal and it is not round as in copper wire. The copper by it base element is more conductive to signals than any other base metal besides gold. Why do you supose they use so much inside antennas?
No never loop the buss. Ringing and feedback will result.
Any booster made in the past 15 years already has termination circuts built in. Early days of DCC suggested buss terminations before modern solid state boosters. Early boosters were not much more than tranformers that stepped up the command stations voltage and digital signal. My former club had an early Lenz booster (I think it was an LZ3) that was 3 amp and had no breaker in it. Any short and there was something fried. Then we wired in some 1156 bulbs. It was later replaced with a modern booster.
Pete
Here is a crude drawing of my layout, not exactly to scale. The existing booster is there in the center of the drawing. I added the likely location of the second booster at the midway point at the upper left of the drawing. The lines represent the bus wires.
Rich
Rich,
Yeah, that’s roughly it. Depending on how close it is to scale, if the second boosterwas moved to the bottom left loop, that would put it closer to halfway. Then the two sets of gaps would be roughly just above where the topmost AISLE is labeled.
Keeping the runs limited in length is really more important that keeping them any exact length or balanced in length. So if that proposed location is good for power supply or other reasons, it’ll be fine. Another consideration is where are the more hevaily used locations. They might be shorter in length because you’ll have more operators or locos going in them than elsewhere. There’s also the case where you may want to split a yard, working one end off of one booster and the other off the other. That way only half the yard will be affected in the event of a short. The same thing applies to the breakers when you place them to protect different power districts.
The idea is to faciltate keeping as many different potential shorts as seprarated as possible with however many breakers you plan to use. Be sure and take them and their gaps and feeds into consideration when possible to save yourself any duplication or complications you can.
Depending on how things are wired into the bus, it’ll be easier or harder to set up the power districts. Essentially, you’ll want to tap into the bus, however you break it up only where it goes directly to the breaker, then everything it protects in its power district runs from it. If you have lots of individual drops off the bus already, this can get complicated. That’s how my layout is, as there’s a few places that it was just easier to leave dependent on the boosters to shut things down. As you noted earlier, plan on getting the yards and industrial areas protected first, as they cause the most issues.
Mike, you are correct. You are getting to know my layout better than I do - - - LOL. My mental math is as bad as my applied math.
The drawing is close to scale in all but one respect. The left side of the layout is longer than shown in the drawing. I used PowerPoint and didn’t take the time to scale it correctly.
The second booster does belong at the bottom of the drawing, not at the upper left, as shown on that previous drawing. On this new drawing, I moved the second booster to the bottom, as you suggested. I then placed an X approximately 40’ in either direction from the position of each booster. That is where I would cut gaps to divide the layout into two segments, with each segment being powered by its own booster.
I should note that this thread started out as a question about the advisability of a continuous loop of bus wire and then progressed into a discussion of an additional booster. I do like the idea of a second booster, but it does raise many complications for what I am contemplating. Right now, I have a single booster and no power districts. I have a RRampMeter wired in line with the booster to constantly monitor the voltage and amps on the layout. I am considering the addition of a PSX-4 to divide the layout into 4 sub-districts, each with its own circuit breaker. If I add a second booster, I will have to add a second RRampMeter. If I add a second booster, I will probably have to go with two PSX-2 circuit breakers, creating two
I’ve found no problem looping a DCC bus on a small layout. An oval of track is a looped bus. What is a small layout? Well that’s one that doesn’t need aditional track power boosters. When you get to the point of adding booster districts, the question of looping the bus goes away because the other end of the bus is too far away to loop.
Martin Myers
Randy, thank you very much for that explanation. I went back and read that portion of the manual and the relevant illustrations. It makes perfect sense to me. Using the circuitous route seen in my diagram above, I will need 93 feet of 4-wire RJ-H cable to connect the two boosters.
Thank you and everyone else responding to this thread. It has been a big help.
Rich
Unless you can go up to the ceiling and over the aisle, or down to the floor and across it. But, a long run for the control bus won’t be a problem.
–Randy
I could do that because there is a wall on the left side of the layout and there is a post right next to the current booster. But, if length is not a problem, I will go the circuitous route under the layout.
Rich
Rich,
For a long run, you may want to use a short RJ jumper from the command station over to a wiring block, run the 4-wire line from it to another wiring block next to the booster, then use the RJ jumper from it to the booster.
My PH-Pro manual says it’s an RJ-H connector and that you can use a regular telephone handset cord to make the connection. Thus the wiring block can be one of those very ordinary 2" square thingies you plug your landline phone into on the wall. The wire in between will be just plain ol’ 4-wire telephone/low voltage cable. It’ll end in another wiring block next to the booster, where a short jumper will connect it there. Just match everything carefully so the wiring keeps the same connection all the way through and it’ll work fine.
Mike, what would be the purpose of the short RJ jumper and the wiring block?
Why not just run the 4-wire telephone/low voltage cable directly into each booster connectionZ?
Rich
Because there’s only the RJ connector at each end of the circuit. That big honking 22 gauge wire is kinda hard to reliably stuff into that RJ socket.[;)]
Essentially, this is the easiest way to do it, close to plug and play. Just so it’s clear what I’m talking about here’s a pic and link to the correct product at Menards, although $7.99 is way pricey[:(] :
The cover comes off and the 4 terminals to hook up your 4-wire low voltage/telephone cable are underneath.
Mike, what am I missing here?
Why not just run a 4-wire cable directly between the two boosters?
Are you saying that the connectors are not the right size?
Rich
The RJ-H is a handset jack - they are smaller than a regular RJ11/12. It’s hard to get long cords with those, normally they are the coiled type. Some crimpers do both sizes, the ones I have do, so if I get the ends I could make such cables. By using the jacks like shown, you can buy one bacis handset cord, cut it in half, and screw the wires to the terminals inside the block, then interconnect the block with an ordinary RJ11 flat wire, which you can easily get in just about any length, even over 100 feet if needed.
That may not be what he had in mind, but going the other way - plugging a cable from teh booster to the jack, adn then just running wire between jacks, well, good luck finding a jack like that with a HANDSET socket on it, it’s just not used like that and they will be hard if not impossible to find.
–Randy
OK, thanks, Randy, I understand the problem.
Here is another question. Once I gap the rails and divide the double main line into two separate booster districts, do I have any concerns as a loco crosses the gaps from one booster district to the other booster district?
Rich
Randy and Rich
Yeah, either way would work, with the main idea being to get from the telco type jacks out of the black boxes to hardwiring for the greater length of the run.
I understand what you mean about the wrong connector on the handset cord, but I thought there was a way to get one that will directly take a handset cord. Maybe scrounged from on old phone is what I think I’ve seen done. In any case, Rich will have trouble finding a 92’ handset cord[:)] so we gotta do something, even if it’s something not quite as elegant as would be ideal.
Rich,
So long as you have the command station and booster cases grounded together as previously discussed, no. The command station takes account of anything that may be needed electrically.