Adding a E-Z Command power booster to Digitrax Zephyr Xtra DCC control system

[pacchardon]

The E-Z Command power booster comes with a cable with 2 bare ends which it says is to be used to connect for another manufacturer's DCC control system. They say connect according to the DCC controller specs. I do not see anywhere in the Zephyr Xtra manual where it addresses how to connect a power booster.

The possible connections on the Zephyr are

Jump1
Jump2
Prog A
Ground
Prog B
Rail A
Rail B
Loconet A
Loconet B

Jump1 thru Rail B the only connections for a bare wire. Loconet A & B are (don't know the proper term) the type of connection you would have for ethernet cable connection

Digitrax support has been no help. Has anyone put these two together? Please help

[pacchardon]

I am going to post a 'nevermind' on this. The instruction DVD on the Brachmann power booster pretty much confirmed what I thought. It appears pretty certain that the output from Rail A & B has to go into the booster, which makes sense. Digitrax support told that was not how to do it, but I don't think they know what they are talking about.

[Jim Banner]

As you suspect, you can connect the input of the E-Z Booster to the rail A and rail B outputs of the Digitrax Zephyr Xtra.  This is simple and straight forward but does not allow you to power one part of your railroad with the Zephyr and another part with the booster.  (You could, however, power two electrically independent railroads with the two outputs.)

The alternative is to connect the input of the E-Z Booster to the rail sync pins of an RJ25 plug (a 6 pin, 6 contact modular plug) and insert the plug into one or the other Loconet sockets.  The rail sync pins are pins 1 and 6, the extreme outside connections to the RJ25 plug.  This will allow you to set up two separate power districts, one powered by the ZX and the other powered by the EZC Booster.  As always, both rails must be gapped at the place or places where two power districts meet.  The two power districts must be phased the same otherwise a locomotive crossing from one power district to the other will cause a short circuit, possibly damaging decoders.  The phase may be changed by reversing the two wires at the booster input.

Jim

[pacchardon]

I don't understand the advantage of the alternative, the RJ25 plug. Doing it the simple straight forward way of using Rail A & B, I think, gives me what I want. It is not going to be a huge layout. Part 1 will be a 5x8 and part 2 will be an additional 4x8. I was planning on the whole thing being 1 power district. Won't the 5 amps from the E-Z booster be enough for a layout that size with no more than 3 trains on it at once. If so, what would be the advantage of having two power districts? Would the Zephyr be in control of the trains in both districts?
Paul

[Jim Banner]

Running only three trains at once should not require a booster at all, unless you are running sound and multiple locomotives per train.  Figure 1/2 amp per silent locomotive or 1 amp per sound locomotive plus 1/10 amp or so for each lighted passenger car.

The availability of more power is not the only reason for dividing a layout into power districts.  The other major advantage, particularly if several people are running trains at once, is that a short circuit at one location will not shut down the whole railroad.

Which ever way you decided to go, the Zephyr would still be your command station, in charge of all the trains.  And which ever way you go, you can still use the Zephyr to program on a separate, electrically independent programming track, even while it is running trains.

The size of the layout has no bearing on how much current it takes to run the trains.  Only the number of locomotives and other power users.

Jim

[pacchardon]

This all good info. The whole thing is slowing starting to come together in my head. One question that I think I know the answer to: If the size of the track doesn't affect the amount of current needed then the need for power feed lines every few feet is to make up for voltage drop thru the track???

[Jim Banner]

This all good info. The whole thing is slowing starting to come together in my head. One question that I think I know the answer to: If the size of the track doesn't affect the amount of current needed then the need for power feed lines every few feet is to make up for voltage drop thru the track???

Exactly.

Jim

[pacchardon]

One more question. Should plugging in the E-Z command booster into the Loconet A or B be sufficient. Is the Zephry going to automatically recognize that something has been added and try to talk to it. Or I am going to need to start pushing buttons on the Zephyr. I have been a round and a round on this with Digitrax tech support and cannot get them to give me a definitive answer on it. They keep begging the question. These are the same people who told me it wouldn't work to connect it to the Rail A & B connections  I have an RJ25 plug on the way, so I will try it when I get it. I'm just hoping to get a preview of what to expect.

[Jim Banner]

Yes it should.  The rail sync connections (the farthest left and farthest right wires on a flat 3 pair cable) carry the digital signal to all the boosters in a Digitrax system.  It is the same as the digital DCC signal put on the tracks except it cannot produce very much current.  The booster's job is to take this signal and boost it up to a higher power level so that there is enough current to run trains.  This could be anywhere from 1 to 10 amps depending on the rating of the booster.  Your Zephyr has an internal booster that takes that same rail sync signal and boosts it up to a 3.5 amp level.  The output of that internal booster is the rail A and rail B connections on the back of your Zephyr.  Note that the signal flows in one direction only - from the command station in your Zephyr to the booster.  And it is always there.  Your Zephyr does not have to detect that you have added a booster or many boosters.  And you do not have to set anything.

I suspect Digitrax is being very conservative when they tell you that you cannot connect the rail A and rail B outputs to a Bachmann booster.  Some boosters might not be too kind to the rail outputs because of different signal levels and different ways of handling the common side of the power supply.  Bachmann has got around this problem by using isolated inputs on it booster.  This means that when you wire up the Bachmann booster, the input signal is converted inside the booster to a beam of light and then back to an electrical signal.  There is NO electrical connection between the Zephyr's output and the boosters power circuits.  You still use wires from the Zephyr's outputs to the boosters inputs, but they carry only a small current to light an LED to produce the beam of light and that beam of light is the only connection into the booster's power circuits.  Having said all that, you can connect the Bachmann booster to either the rail A and rail B outputs on the long plug or to the rail sync connections at the Loconet A or Loconet B connectors.  Do not, however, try connecting it to more than one place at the same time.  Your Zephyr will become really unhappy if you connect any loconet pins to any of the input and output pins on the long plug.

Jim

[pacchardon]

Once again, good info. Some of this I suspected, some I didn't have a clue about.
Thanks
Paul