Battery power

[Greg Elmassian]

Not to belabor the point, but traditionally, decoders have taken power input and signal input from the same "leads" because that's how DCC is done.

Some DCC decoders will accept a low power DCC signal, and accept power on separate connections, but this is not a universal ability, and I have not seen any decoders so set up, you have to "find" the places to "hook in".

The Gwire provides a low voltage low current DCC power/signal. The Gwire was intended for the QSI which was designed to not only accept the Gwire signals, but to STOP interpreting any DCC signal on the track inputs at the same time.

I just want to be clear on expectations of this to work. I know that Lenz decoders can be used, as Stan Ames has shown, and "found" the "magic connections". I have not researched other decoders that will work.

I'm frankly somewhat surprised that QSI solutions did not add some caveats on the circuit, but they are in business to make money too.

Regards, Greg

 

[kstrong]

We're on the same page, Greg, just stating things from different perspectives. My perception is that the decoder inherently needs an "extermal" power source; that the G-wire receiver just provides the control signals to the decoder, whether the decoder can function on 5 volts or not. To my understanding, the G-wire receiver is not designed to provide primary power to the decoder at all.  

BTW, I use the term "argument" in the "debate class" sense of being a point of debate or discussion, not as a reference to any kind of heated exchange.

Later,

K

[Greg Elmassian]

"Your argument (as I understand it) is that in doing so, you inherently limit the functionality of the decoder the G-wire is controlling to low-voltage, low-current devices such as lights and sounds because that's all you've got from the G-wire output--5 volts."

1. No, there is no agument.

2. No, that is not my point (not argument)

3. I stated it a couple of times already, the decoder needs a certain amount of power to operate period. Not all decoders will run on the voltage provided from the Gwire receiver, which is 5 volts and limited in amperage.

4. A more brief rendition of #3 above: It won't work for all decoders, period. The "IT" refers to even having the decoder operate period. In DCC, no one runs a track voltage of 5 volts, and so no one guarantees their decoders operate at that voltage.

Hopefully I have clarified and corrected any misconceptions on what I have written.

The reason I am going to great lengths to clarify is so that people new to this will not buy something only to not have it work.

Regards, Greg

[kstrong]

I think we're looking at the same thing from two different angles. Yes, the decoder  in the example is (likely) being powered by 5 volts from the G-wire receiver. (I'll assume there are no missing connections, nor is the board somehow getting power through the light inputs.) Your argument (as I understand it) is that in doing so, you inherently limit the functionality of the decoder the G-wire is controlling to low-voltage, low-current devices such as lights and sounds because that's all you've got from the G-wire output--5 volts. I can easily see that being the case if you hook the output of the G-wire to the "track input" on the decoder and leave it at that. The problem with that is that there's no reason that the features being controlled have to be limited in voltage to the 5 volts coming from the G-wire to the decoder. The decoder merely opens and closes the valve. It doesn't care how big the pipe or the temperature of the water.

That's what I was drawing your attention to with the diagram. It illustrates a case where the 5 volts coming from the G-wire receiver to the decoder controls a function powered by more than 5 volts. In this case, it's a light, but it could just as easily be a motor (providing the decoder could handle the current.) 

It does depend very much on the decoder, and it's not as simple as just attaching the outputs of the G-wire receiver to the "track" inputs on the decoder. You can see this in their first illustration, showing how to connect the G-wire to their HO-scale decoder. You have to know where to tie into the particular decoder. Perhaps that's why they offer the second sentence in this excerpt from their web site.

"Most other DCC mobile decoders and stationary decoders can also be connected to the GWire receiver. If you have a special request we can do the wiring for you or send the instructions." (italics mine)

Having said all that, I think this is probably a discussion limited in relevance to those who already own a bunch of DCC-equipped locos with decoders already installed. Anyone coming to this fresh would be well served either by the G-wire/QSI combination or by using the full-blown Airwire G2 receiver/decoder board, then hooking up a 3rd-party sound system to that to get the DCC functionality. It may be possible, but it may not be worthwhile.

Later,

K

[Greg Elmassian]

Look at that last schematic again, the "full power" is used to light the lights, it is NOT powering the decoder.

It's just that not all decoders do what you see in some of the circuits.

Greg

[Greg Elmassian]

Wrong.

Not every decoder has a power input separate from the signal input.

Look at the schematics on the site, they are powering the decoder from the output of the receiver which is 5 volts.

Some decoders will work at 5 volts some will not.

You will see if you look.

Greg

[kstrong]

Please note that the "generic" DCC decoder is really intended to be a sound decoder, because the voltage supplied to the DCC decoder is 5 volts. Used for a motor decoder, or motor/sound decoder, your loco won't move very fast at that speed!!!

Not the case. The power for the receiver is 5 volts, but the power for the decoder can be whatever it's capable of handling; usually between 18 - 24 volts depending on the decoder. The receiver gets its power from the decoder via a 5-volt tap (as is the case on the QSI circuits), or alternately from a 5-volt voltage regulator circuit tapped off of the battery output directly. You're still running full voltage to the decoder the receiver is controlling. See the last circuit diagram on the QSI page. They're using a lighting control decoder as an example, but I can't think of any reason why it couldn't be a full-function decoder. What it's doing in that example is no different from what the receiver does with the QSI board it was designed to directly interface with. All it's doing is providing the DCC signal; the batteries are supplying the base power for everything.

Later,

K

[Greg Elmassian]

I stand corrected, and thank you Kevin.

I would really not say "supported" until QSI Solutions would state if they warranted the Receiver against damage in that generic connection. Showing a schematic without a guarantee is far from a warranted solution.

I seriously doubt it would be a completely "warranted" solution, but this is just intelligent speculation on my part.

Please note that the example of the Quantum 1 mentioned in the circuits earlier is an HO decoder, even though the article starts out mentioning Aristo Magnum.

Most G scale decoders draw way too much current for that circuit to work at all. That board does not source much current, and definitely it's limited to 5 volts. Many G scale DCC decoders do not turn on at that voltage

An O scale might work.

It's also not merely a question of voltage and current.

Anyway, I would not recommend this without the proviso that it's not guaranteed to work.

Please note that the "generic" DCC decoder is really intended to be a sound decoder, because the voltage supplied to the DCC decoder is 5 volts. Used for a motor decoder, or motor/sound decoder, your loco won't move very fast at that speed!!! 

I'd ask QSI solutions about the specific implementation first and get their blessing.

Regards, Greg

[kstrong]

Greg, thanks for clarifying my post. It can definitely get confusing with Airwire making components for NCE, etc. and so forth. One quick correction, though:

4. Some people HAVE hooked the QSI "Gwire" radio receiver to SOME DCC decoders, but not all will work, and this is not a manufacturer-supported configuration, nor was it ever advertised this way.

QSI's web site has a wiring diagram showing how to hook the G-wire receiver up to generic DCC decoders under both track and battery power.

http://www.qsisolutions.com/news/09/gwire-receiver-090309.html

Quoting, "Most other DCC mobile decoders and stationary decoders can also be connected to the GWire receiver." You are likely correct that not "all" will work, but it is supported by the manufacturer.

The $64,000 question is twofold ($32K a piece?)--(a) will the Tsunami in the Shay work in this configuration, and (b) if so, where do you wire in the connections. Someone at QSI or Soundtraxx may be able to answer one or both of those questions if one were intent on doing so.

I tend to agree with you, it's probably more trouble than it's worth, especially when you factor in some of the limitations of the factory DCC, such as the 21-volt ceiling (not really a concern under battery power unless you really wanted to cram extra batteries in) and wasn't there a current-handling issue as well? I don't remember. My recollection is that they basically used an O-scale decoder for this loco, and it proved to be a bit underpowered. Don't quote me on that, but I seem to recall problems of that ilk leading to the implementation of the "socket" in Bachmann's K-27 as a remedy.

Later,

K

[recaper]

TonyWalsham

The 3 truck Shay was designed for track powered DCC.
I know of no way you can battery power the Tsunami sound system fitted to the 3 truck Shay.  The Tsunami will have to be replaced with something else.
Here is how I went about installing my RCS battery R/C and Phoenix sound in a customers 3 truck Shay:

http://www.mylargescale.com/Community/Forums/tabid/56/aff/35/aft/103183/afv/topic/Default.aspx

It will be similarly quite possible to do it with the small Porter.

Thanks Tony! Great pics! Lots of info,but i don't know if i have the skill needed for that .Tom

[Greg Elmassian]

There's a little confusion here, maybe I can help correct:

 

1. If you want to use the CVP "Airwire" "system" you can use two different throttles/cabs interchangeably, the one made by CVP and the one made by NCE.

2. Using the same "system" you have a couple of ways to go for decoders. The first way is purchase a CVP receiver/decoder. This has the radio receiver and the motor decoder. There are/were 2 flavors, but both work the same way. There is NO sound on this board, but there is a "DCC" output that will drive virtually any DCC decoder. It is intended for a DCC sound decoder, like a Phoenix, but other things are possible.

3. The second way to go for a decoder is the QSI motor/sound decoder. This works on DC or DCC. To make it work with the Airwire system, you ADD the QSI  "Gwire" receiver radio module, which is intended only for the QSI. It plugs in. This gives you integrated motor/sound capability. It also gives you track power DC and track power DCC capability (the receiver module is not needed in these modes)

4. Some people HAVE hooked the QSI "Gwire" radio receiver to SOME DCC decoders, but not all will work, and this is not a manufacturer-supported configuration, nor was it ever advertised this way.

So that's the "DCC over the air" story, specifically Airwire type system.

Of course it is not the only way to do battery power, but I think I have written enough!

 

Regards, Greg

[TonyWalsham]

The 3 truck Shay was designed for track powered DCC.
I know of no way you can battery power the Tsunami sound system fitted to the 3 truck Shay.  The Tsunami will have to be replaced with something else.
Here is how I went about installing my RCS battery R/C and Phoenix sound in a customers 3 truck Shay:

http://www.mylargescale.com/Community/Forums/tabid/56/aff/35/aft/103183/afv/topic/Default.aspx

It will be similarly quite possible to do it with the small Porter.

[kstrong]

Much depends on whose control system you're going with. Assuming you want to stay with one of the DCC-protocol-based systems, that leaves you with Airwire and/or NCE controllers. I don't have any first-hand knowledge relative to installing the into the Shay with its factory DCC decoder, but here are some theories which you can e-mail the manufacturers and get their opinions.

First, the Airwire decoder/throttle has a DCC out which passes the DCC signals to sound systems and other decoders (lights, etc.) I would think it's possible to use that decoder/throttle and the DCC output to pass the DCC signals to the stock Bachmann board. You'll want to disconnect the track pick-ups (which may be a switch, but check with an ohm-meter unless you're physically cutting wires--the only foolproof method.) What I don't know is whether the DCC output from the Airwire board passes throttle/motor settings or what. If it passes the throttle/motor settings, then you can just use the Airwire card as an input for the battery power and DCC receiver, using the factory DCC as intended at that point.Otherwise, you can connect the motors and lights to the Airwire board, and just use the sounds from the factory board.

A second thought--use Airwire's "G-wire" receiver, which is strictly a battery input/DCC signal receiver/encoder. This circuit has solder pads to which you can hook it to anyone's DCC decoder, according to the manual. This would allow you to use the factory DCC for both motor and sound control.

Again, I emphasize this is theoretical, based on how I've interpreted the instructions from the on-line manuals. I haven't done this myself.

If you're looking at anyone else's non-DCC wireless battery R/C system (Aristo's "Revolution, LocoLink, RCS, etc.), you're out of luck on keeping the factory DCC. You'll have to gut it and buy a new sound system. You may have some luck selling the DCC to recoup some of your expense.

As for the Porter, it's "DCC ready" in that it has a plug (likely the NMRA-standard 8-pin plug; I know it's not the "socket" that's used in some larger large-scale locos) to accept a DCC decoder. To take advantage of that and battery power, you'd have to figure out which pins go to what, and wire an interface between whichever control system you use and that socket. There are no battery R/C DCC systems that use that 8-pin socket as standard. Given the tight space inside the porter, I'd advise just gutting the factory electronics and wiring everything direct to the new stuff anyway.

Later,

K

[recaper]

I,m new to the forum, and new to garden railroading, I have a 3 truck Bachmann shay and a Bachmann porter. I would like to convert to battery power, the shay has factory sound and dcc the porter is dcc ready,is the shay able to hold a battery pack and receiver,can i keep the dcc? Any help would be appreciated !