RailPro and DCC Modules Compatability

[LanOsb133]

Hello all!  I plan on joining a local Module MRR group that operates on DCC.  I would like to make my modules for DCC since Railpro will also run on them.  However. I was wondering if the Railpro powersupply will power the tracks correctly for DCC users, or if I will have to wire the tracks with DCC power and have it set up for them and than just enjoy my railpro features on just my engines.

Thanks for any info!

[Alan]

Sadly, you will have to wire for DCC because a DCC booster applies both the motor power and the digital control signal to the rails. Your RP trains will run fine on the DCC wiring.

[G8B4Life]

Well the RailPro power supply won't work for DCC though a DCC supply will work for RailPro so you can't use them at the same time however that has little to do with the actual wiring you need to include on the module. The good news is the difference in wiring for DCC and wiring for RailPro is very little.

Without knowing which module standard the club follows I'll make some guesses to what's needed by the module standard they use.

You will need a track bus. It's wired the same for DCC and RailPro, ie probably just two wires with feeders. Being modular it'll have some sort of connector at each end. You can easily add this connector to your RailPro supply for home use.

They may have an accessory bus. This would be the same as for the track bus (except without feeders to the track) and is no different for DCC as for RailPro.

You'll most likely need to include a command/throttle bus and possibly throttle panels on the modules. This wiring has no bearing on RailPro at all but is needed for DCC.

If you follow the wiring standard used by the club for the modules then your modules will work just fine for both DCC and RailPro - as long as you don't try to use a DCC power supply and a RailPro power supply at the same time. The only other thing you'd probably have to worry about is if your modules have turnouts and they are live frog; you'd need to employ some sort of active polarity switching for the frog and not use one of the "auto" types of frog juicers; most don't work on plain DC which will stop you having more fun when running from a RailPro supply.

- Tim

[LanOsb133]

Sadly, you will have to wire for DCC because a DCC booster applies both the motor power and the digital control signal to the rails. Your RP trains will run fine on the DCC wiring.

Well the RailPro power supply won't work for DCC though a DCC supply will work for RailPro so you can't use them at the same time however that has little to do with the actual wiring you need to include on the module. The good news is the difference in wiring for DCC and wiring for RailPro is very little.

Without knowing which module standard the club follows I'll make some guesses to what's needed by the module standard they use.

You will need a track bus. It's wired the same for DCC and RailPro, ie probably just two wires with feeders. Being modular it'll have some sort of connector at each end. You can easily add this connector to your RailPro supply for home use.

They may have an accessory bus. This would be the same as for the track bus (except without feeders to the track) and is no different for DCC as for RailPro.

You'll most likely need to include a command/throttle bus and possibly throttle panels on the modules. This wiring has no bearing on RailPro at all but is needed for DCC.

If you follow the wiring standard used by the club for the modules then your modules will work just fine for both DCC and RailPro - as long as you don't try to use a DCC power supply and a RailPro power supply at the same time. The only other thing you'd probably have to worry about is if your modules have turnouts and they are live frog; you'd need to employ some sort of active polarity switching for the frog and not use one of the "auto" types of frog juicers; most don't work on plain DC which will stop you having more fun when running from a RailPro supply.

- Tim

Thanks for the insight guys, I figured this was the case but wanted to clarify before I started building my little switching modules.  Tim so if I wired it all up for DCC, and I was at home, I could still plug in the Rail Pro power supply and power the tracks and than unplug it and take it to the club and have them plug in all the DCC stuff and it should (theoretically) work for them?  Given of course that all the wiring is done correctly?  I would love to be able to run my modules that way if possible.

[Alan]

I could still plug in the Rail Pro power supply and power the tracks and than unplug it and take it to the club

If I may answer for Tim...

Yes, you can do that. Simply connect the RP power supply to the track bus connector you have for the DCC booster connection. At the club attach their DCC booster, at home attach the RP power supply.

An easy way to think of this is DCC power has two components in series, a power supply and a booster, whereas RP has one, a power supply. Track and layout wiring are the same. If the club uses Loconet you may also need to install a Loconet cable running the length of your modules. It won't actually connect to anything on your modules but it will need to be there to maintain the club's module-to-module Loconet circuit.

Tim makes a very good point about the frogs. DCC juicers don't work on RP DC. To be compatible with both RP and DCC you either go dead frog or use switch motor / manual lever electrical contacts for frog juicing.

A completely different route to go would be to use a complete DCC setup on your modules (minus throttles) and then simply run RP trains on it. The advantage is you can then use DCC frog juicers, auto reversers, occupancy detectors, etcetera for complete interoperability with the club. The obvious disadvantage is cost. 

[nodcc4me]

I have found that one other disadvantage to running DCC on your modules will be the need to clean your track frequently. That is the biggest problem I have experienced while trying to run my RP engines at the club. RP modules seem to be very sensitive to dirty track.

[G8B4Life]

Thanks for the insight guys, I figured this was the case but wanted to clarify before I started building my little switching modules.  Tim so if I wired it all up for DCC, and I was at home, I could still plug in the Rail Pro power supply and power the tracks and than unplug it and take it to the club and have them plug in all the DCC stuff and it should (theoretically) work for them?  Given of course that all the wiring is done correctly?  I would love to be able to run my modules that way if possible.

Alan has answered this quite well but yes, you will be able to do that. Are the module specs that the club uses online? if they are point us to them and we can ascertain once and for all anything that might throw a spanner in the works.

 . . .

Alan brings up an interesting point on powering with DCC at home as well so DCC frog juicers could be used, and I'm just pondering this in my head and not actually suggesting what has been suggested to be a viable solution to any RailPro user that needs dual capability for auto polarity live frogs. I wonder if one could get away with powering with just a booster and not needing a command station for at home use. A second hand booster only for home use would be a lot cheaper than a complete DCC system sans throttles just for powering RailPro at home so DCC frog juicers can be used.

- Tim

[Alan]

booster - command station

Different words for the same thing?

[G8B4Life]

booster - command station

Different words for the same thing?

No they are separate things. A command station can incorporate a booster but a booster cannot incorporate a command station. Let me explain that better.

A command station takes input from devices (usually throttles) and outputs the required DCC packets to the command station output. This command station output is usually "boosted" by an internal booster, but not always.

A booster takes input from the command station output (usually a separate low level line for stand alone boosters but contains the same DCC packets) and amplifies them (boosting) for outputting to the track. A stand alone booster cannot accept throttle input or generate DCC packets by itself.

Stand alone boosters are used to divide a large layout up into power districts and as such there is a need to get the DCC packets from the command station to the districts.

- Tim

[Alan]

Ah yes. Sorry, was thinking Zephyr / PowerCab style. Relative to the OP's question we can think of the command station and booster as a single component, no?

[G8B4Life]

I'm not sure that I'd call the NCE PowerCab "boosted" by any means by itself due to the low amount of power it can provide but yes Zephyr / PowerCab style include integral boosters much like most command stations these days. I'm not actually sure you could find a command station these days that doesn't have a booster built in but if one looked hard enough you could probably find one.

In relation to the OP's question and the suggestion of "using" DCC at home to provide power for RailPro and that we can think of the command station and booster as a single component this is what I'm pondering.  A stand alone booster is cheaper than a command station. Since the OP has no need of the command station functionality and it would be a waste of resources (money) to have one just to be able to use things like DCC frog juicers for club use; if a stand alone booster could generate the DCC AC waveform at least without needing command station input then that would be a cheaper avenue than having to get a command station of which he''d only use the power from.

I don't have a stand alone booster so I can't test my theory to prove or disprove it.

Edit: Thinking about this further, if a stand alone booster can't generate the DCC waveform by itself without command station input then the OP could still possibly get by with a stand alone booster and a "DCC waveform generator" for want of a better word to plug into it; not that I know of any DCC waveform generators out there but it could be worth looking into.

- Tim

[Alan]

If all you need is the 10kHz square wave on the rails then that is pathetically easy to do. A darlington pair transistor arrangement on the output would provide all the amperage you could ever want eliminating the need for a booster.

[G8B4Life]

I feel like we're hijacking LanOsb133's thread for our own conversation even through we're really not.

A very interesting idea you present there Alan. I'm quite sure all you would need is the raw AC waveform (say all zero's at 100μs); an LM doesn't need the coded waveform and I doubt that non controllable DCC items, like juicers need a coded waveform either. The only thing I can think of that prevents at least me from seeing how pathetically easy this is is don't the rails need to be in opposite phase to each other? I'm sure with a few extra components you could create an opposite phase copy of the darlington pair output but remember, not an electronics genius here.

- Tim

[Alan]

V_out in the schematic is the two rails. Notice V_cc is - and + instead of the usual + and GND.

And yes, the output transistors would need to be a push-pull configuration.

[G8B4Life]

I'll take your word for it at the moment, right now the sandman beckons.

I have sent Tim Ring an email about using a generated raw DCC waveform. Will be interesting to see what he says; probably something about starting a fire 

- Tim