Is this DCC idea practical?

[ndbprr]

the big problem with control whether DCC or DC is track contact. With the high output batteries available today would it be possible to replicate what our radio controlled airplane brethren do by putting the batteries in a dummy unit with a radio receiver and the decoder to control the lead unit? That way the train is totaly independent of the track - just like the real thing. A section of track in a staging or engine house area could be used to recharge the batteries when needed. An auto shut off feature would prevent overcharging and the natural isolation of the wheels would allow the track to be the means to recharge the batteries. Hence only a small portion of the track ever would neeed cleaning and running time would dictate engine changes which is another operating session item. My thinking is HO and bigger this should be readily feasble. N I'm not so sure.

[grandeman]

Standard DCC work so incredibly well that this wouldn't be worthwhile, IMHO. Recharging/replacing batteries all the time would get old. It's a great idea for outdoor RR's though. There, the advantages would outweigh the disadvantages but indoors I'll stick with DCC.

[jeffshultz]

I don't know if it's practical for HO or N, but didn't some outfit demonstrate something similar in large scale at the last NMRA Convention? Ran a train without tracks even...

[jfugate]

Yes, Jeff, CVP -- the makers of EasyDCC did just this -- but it was for large scale (G). See: http://www.cvpusa.com/airwire900_system_info.php

However, their wireless/battery powered DCC uses a combination decoder and receiver that should just barely fit into an HO dummy locomotive. I've spoken with CVP and they have told me some of their customers have tried this and gotten it to work.

I was thinking of trying it out myself, and rolling the video cameras while I do it ... then reporting on the result.

I'm thinking of a three unit lashup wired together with the middle unit being a dummy with the reciever, batteries, and sound ... to give the impression the entire lashup has sound. The other two locos on the ends would have decoders with lights, but I would wire the red and black wires to the output of the CVP receiver.

CVP's AirWire900 system includes a wireless throttle that lets you operate the loco, program it on the fly, etc. Still some details to work out, but I'm thinking this might be worth a try to see how long the rechargable batteries last, etc.

Anyone interested in me conducting such an experiment and then producing a video to report on the results?

[Anonymous]

This or similar is done a lot in large scale gardens railroads. At some point I think that radio control with batteries MAY be realized. For N scale, the trick is not the electonics, it is the motor and mechanical stuff. The answer might be motors on the axles (kind of prorotype like, freeing up insode room for batteries and receiver. Of course now we have to keep the batteries charged.

It will be fun to see what is going on in twenty or thirty years, though....

[MisterBeasley]

I've got a micro video camera, which is battery powered. It goes through a 9-volt battery in a few hours. From this experience with something that's really a small user of power, I'd think you'd really need big batteries to provide smooth power for a locomotive pulling a train. You're probably on the right track with a dummy engine, but what do you do when you're running a switcher, or even a steamer where the tender is already stuffed with speakers?

Also, my experience with using radio transmission for the video is that it's full of dropouts, and subject to interference. I think I'll stick to keeping my track and wheels clean, for now anyway.

[Rotorranch]

Assuming an amp draw of 1.0 amps per locomotive, ( I know it's a little high, but it makes the math easier! ), a 1200 ma rated NiCd battery would run a train for 1.2 hours. Many of the newer Nimh batteries are 3000-3600 ma which would give 3.0-3.6 hours of run time. The drawback of these cells in model railroading would be size. The Sub-C cells are just slightly smaller than normal C size batteries and you would need 10 of them to achieve the 12v nomimal to run a standard loco.

However, an alternative may be lithium, ( Lipo ) batteries, although these are rather more expensive, and I'm not sure if they are rechageable.

Rotor

[jfugate]

I'm thinking two rechargable 9 volt batteries in the dummy unit, 270mAH, with typical motor draw of 0.1 amp x 2 motors, plus another .2 amps for sound ... perhaps an hour's worth of constant operation. But at least on my layout, an hours worth of train operation does not translate into an hour's worth of constant "on" at full throttle. About half that time is sitting in the hole waiting for other traffic.

Point is, it's borderline practical, and I'd like to see how practical.

[grayfox1119]

There are new batteries being designed as we speak that will be more powerful than Nimh, and much smaller. Size of the deep cycle batteries and re-charge time are the only drawbacks that I see to using this great idea. That would put an end to problems of contacts, frogs, points, sidings crossovers, districts would be a thing of the past. This is the ultimate as far as I am concerned, and the way of the future for our hobby.
BTW, JOE I am all for it, go for it, I am interested, and will be one of the first to try this. THIS IS THE WAY OF THE FUTURE FOR MRR !!

[rrinker]

With some of the super capacitors we have these days - it could probably be done without batteries that, no matter what variation of today's technology they use, eventually wear out and need to be replaced.

The simple expedient of powering all track but reversing sections and using that to keep said capacitor topped up is probably the best answer. It would take a long time before enough track got dirty that the cap never got to recharge, yet you wouldn't have to keep stopping for a charge - although that could be part of a prototype operation, particularly with steam locos - FORCED 'water' stops to recharge the power supply! Diesels, on the other hand, typically go a long time between fuelings - over on the Trainboard forums there is an ongoing series of 'classes' by a real locomotive engineer who indicates on his line they typically refuel their SD45's only twice a week - and an SD45 isn't exactly the most fuel-efficient loco around! And they have plenty of grades to haul, it's not an easy flatland trip they make on a daily basis.

One thing to keep in mind with direct radio control to the loco - better not use any of that old metal screening or chicken wire-type scenery! Steel stud benchwork might also cause radio reception issues.

--Randy

[Anonymous]

The idea is practical, but.

In the late 80's or early 90"s Bachmann sold a large scale ten wheeler that was battery operated and radio controlled. The battery was a 7.2 volt ni-cad and the transmitter transmitted in the same frequency that was used by model airplanes. On an outdoor layout it worked well enough when the transmitter was in sight of the loco. Behind a hill or in a tunnel was a different story. But remember, I was using this loco in the early ninety's. Much has improved since then.

The 7.2 ni-cd batteries did not last that long and they needed four to five hours to recharge.

I eventually heard that some large scalers were moving to 12v gel cells so I gave that a shot. It certainly increased the loco power ( I reduce the voltage from 12v to something over 8 ) and more importantly the battery life.

I read that one person had a section of track on his layout that was powered by a battery charger and when the loco needed to be charged he would stop it on that section of track.

My personnel belief is that the day will come when we will not be operating our trains from track power. With electronics getting smaller and smaller all the time and the advances in battery technology that form of power and control is the most feasible.

Just my opinion

Joe

[jeffshultz]

I'd rather that the sound decoder people worked out a way to stick a big enough capacitor on the decoder that it ignored the frogs and other temporary dead spots on the track instead of fuzzing out.

That said... do you think a dummy SD45 or SD45T-2 would be big enough?

[grayfox1119]

There will be plenty of room. If you look at what size computers once were, the size of a room, and full of vacuum tubes, then mid size PDP computers, then PC's, then hand helds...you get the point. We now have imbeded chips, and small powerful button batteries. So the answer is......yes, we will have trains not run on track power, and there will sound chips small enough that they will fit just fine in the locos, as well as the power sources. Even motors are now mcro sized and very powerful.

[cacole]

I run all of my G-scale equipment with the CVP AirWire900 battery-powered Wireless DCC system and can tell you that there is no way you would ever get an AirWire900 receiver/decoder into anything smaller than an HO scale box car, not including the batteries. The receiver/decoder measures 1.43 x 4.23 inches without any wires connected to it. There is a 6-screw terminal strip on one end for the input voltage and motor outputs, which adds to its overall length. A smaller 8-screw terminal strip on one side is for Auxiliary DCC outputs, lights, and a smoke generator.

And then there is a 3" long antenna to contend with, which would preclude running through any tunnels or bridges.

The AirWire900 receiver/decoder has a 10 Amp capacity for G-scale use, and that is one of the things that is keeping it large. Not to mention that an AirWire900 receiver/decoder costs much more than any other DCC decoder. And you also need an AirWire900 transmitter for each operator.

You can learn all about the AirWire900 by going to the CVP web site and clicking on the AirWire900 tab at the top of the page: http://www.cvpusa.com

As a member of an HO scale club with over 200 DCC equipped locomotives, I can say that trying to use the AirWire900 is a very expensive, high-tech solution to a non-problem. Just keep your track and wheels clean, and you should have no contact problems.

[olequa]

Recharging the onboard battery would not be a problem. AC or DC could be applied to the tracks such that the battery could be constantly recharged. There would have to be engine length dead sections to prevent shorts at reverse loops, but that wouldn't matter with respect to running.

[Anonymous]

I have not seen the "consumer package" for rechargeable Lithium batteries at this point, except for cell phones and digital cameras in their own specialized packages. Nickle Metal Hydride batteries have a unique charging cycle that involves spikes of energy which helps to break up the oxididation within the cells making up the battery package. This charging method eliminates for the most part the "memory" problem with Nickle cadmium cells.
I am not sure how the model aircraft hobbists are powering their motors but I believe they put together packages of AAA or AA to provide the needed voltage for short duration climb and flight. A number of these aircraft are flown as gliders using their motors only to haul them to a sufficient altitude to provide long term flight using wind currents and thermals for lift. The primary concern here as with all aircraft is weight, thus the smaller the battery package the better.
The RC cars have used high performance 7.2 and 9.6 volt battery packs for a number of years. These tend to be both bulky and heavy, which would make available battery packs difficult to "hide" in an HO engine, and add significant weight to be lugged by the motive power.
One possible way to address this idea is not a full time power source, but as a backup for those power interuptions caused intermittently by dirty track and frogs in turnouts, etc.. This might also allow for a continuous battery refresh when there is good power to the loco so equipped.
Just a few thoughts to be added to the mix.

Will

[Don Gibson]

BATTERY technology has woefully lagged on the electrical scene. Lithium, and Siver Oxide's have vied with Alkaline ; and Ni Cad with Lead Acid, but the combination of size vs. storage vs.cost is still pretty archaic.

AT A SHOW, There was an engineer showing his HO train running on a single rechargable 9v NiCad . He had an engine that pulled 0.2a and a couple of cars. . His ' Enginering service' was pulling a rear gear assembly out and substitute the 9v nicad - thereby powering the front 4 wheels.

He changed the battery about every 3/4hr. His 'Thrust' was for the Garden Railroad market , where the RF control makes sense, and interior space is more generous; and he was using an Aristo hand held RF controller. Anyone else see this?

SOUND's like a forerunner of the CVP 'Air wire'.

[DigitalGriffin]

Get a series of Lenz Gold decoders with their new power backup module if you are worried about dropouts.

[ereimer]

if you look at the tiny radio control cars that were a big hit the last couple of christmas's and the small battery powered r/c helicopters now available it doesn't take a huge leap of imagination to see radio control coming to HO model trains in the next few years . the problem i see with r/c and trains is getting enough frequencies to run a decent sized layout unless there is also some kind of encoding / decoding of signals going on like DCC . hmm i guess i just solved that problem !

[dehusman]

Its entirely possible since it was done about 20-25 years ago (there was a series of articles in RMC about it) using an A-B set of F units. You could set the engine on a tble and run it back and forth with no track. With better batteries and smaller electronics it would take less volume to contain the system, but still might need a "dummy" unit as a rolling battery pack.

Dave H.

[Anonymous]

I'm not seeing a huge benefit. I think that decoders that can hold up their power supply long enough to get over a frog, or a dirty spot, solve most of the issues. Then you use the space you save by not having batteries to put in better speakers. You are going to keep power on the track to charge the batteries, so why not just use it to run? (Of course I could be wrong....)
The RF interference problems could be an issue. Flying modellers go to a lot of trouble to make sure they don't step on each other. The other thing would be interference in the layout room. There are already some issues with wireless throttles that I read about now and then, wireless control would have the same problems, maybe more since the receiver would be right next to a motor. The encoding/decoding thing doesn't totally work, since you'd have multiple transmitters on the same frequency. DCC works because there is only one transmitter on the track, so to speak.

[bikerraypa]

QUOTE: Originally posted by Rotorranch



However, an alternative may be lithium, ( Lipo ) batteries, although these are rather more expensive, and I'm not sure if they are rechageable.

Rotor

LiPo batteries are rechargeable but can be quite finicky (I fly RC as well as doing MRR). Although they are a bit more complicated to recharge, the savings in weight over NiCd or NiMH batteries is tremendous, as is the lasting power. Unlike NiCd or NiMH batteries, LiPo's don't really "slow down". They deliver power from start to finish, hence the advantage in RC flight. LiPo technology, combined with some of the amazing things being done with brushless electric motors, will probably make RC/MRR practical sooner than most of us think.

RC flight has gotten to the point where LiPo batteries are as common as the sub-C NiMH batteries, and even large-scale planes get more power and more time from brushless motors and LiPo batteries than they were getting from glow engines!

Battery guru Red Scholefield has an awesome website at http://www.rcbatteryclinic.com/ if you want to do more battery reading, or visit the Batteries forum at WattFlyer http://www.wattflyer.com/forums/


Ray out

[BRAKIE]

Think outside of the current battries..I have a defibrillator implant that runs off a 7 year battery..So..
I think that as electronics get smaller DCC and DC will seem like playing video games on the old home game machines of the 80s..I fully beliee that long life batteries will be the power source...

[gvdobler]

Speaking from a radio control airplane background. Running the contrrol part of the train might be practical via remote control, but powering the loco's drive motors would seem like a lot of trouble.

I do power things like the retractable landing gear on a separate battery so there is no chance of a voltage drop to the control radio receiver.

I keep 5 or 6 airplanes flyable at any given time, and I can tell you keeping up with the battery maintenance is a lot of checking, cycling, charging and such and trying to do the same for very many on a model railroad would be a lot of work.

[grayfox1119]

When the batteries become small enough, and long duty cyles are the norm, they will be in our trains for sure. It is only a matter of time, and sooner rather than later. Just look at the video cameras 20 years ago. Remember those two big boxes you had to carry around? Now you can fit the camera, the playback, etc all in one unit in the palm of your hand. Batteries are becoming more efficient and long cycled between charging, as well as smaller every 18 months on average. As for charging, the locos will be charged by parking them on railyard siding tracks to recharge while idle.

[rolleiman]

I'll stick with the current system.. Interesting idea though.. Just let the rail tops blacken as not having to clean the track is the only advantage I could see to this.. Of course, with your idea, it's no longer DCC but RC..

Jeff