I’m seeing bits and pieces of info about it but I still don’t know exactly what it is? More importantly, if I do upgrade to DCC will my existing setup still work with it? I’ll settle for a good link to an article. Thanks.
DCC = digital command control
In layman’s terms, it allows independent control of locomotives with only two wires going to the track. It’s to model trains what radio control is to model airplanes.
For more, see: http://www.dcc.info/
I’ll use my own (many more) words to elaborate on Joe’s excellent, and succinct, reply.
If you have ever waded through, by solder or screwdriver, the dozens of terminals and switches, and miles of wire, in DC (ye olde way) of running a layout, then you will appreciate how marvelous DCC(nu way) is when you first start your own trains on such a layout.
As others had described it elsewhere, in DC you run the layout…fight it is more accurate.
In DCC, you instruct your locomotives to make sounds, turn on/off lights, work with other locomotives in consists, and generally to behave like civilized locomotives should.
It is, if I may be permitted to take a shot at another analogy, the difference between a vacuum tube and the transistor; you can still get vacuum tubes, but it ain’t fun.
A different view.
I assume you know how straight DC works. DCC utilizes track that is powered all the time with AC, and the decoder in the loco (or anything else) receives signals thru the track and converts the AC to measured DC, allowing the loco to move forward, or back, or at any speed independent of any other locos on the track, turn on and off lights, or whatever, unless you program two or more to respond to the same signals, as in a consist. Depending on how you like to run your trains, it can be a great tool. Or, for some people who just love to twiddle with electronic stuff, playing with DCC is an end in itself.
I am still DC. I haven’t seen where it offers me much advantage. And there will be a big conversion cost, so I would have to run a dual power set up for quite awhile I think. Depending on where sound goes from here, I may have to go to DCC to get what I want in that arena, but if the QSI methodology prevails, probably not. I have never had any problems with wiring for DC, I mean it is pretty darned simple; two leads. QSI doesn’t sell DCC systems, so they have developed decoders/sound systems that work with DC or DCC, Soundtrax appears trying to go the same way with the Tsunami if the rumors are true, wheras Digitrax is only going to offer sound that goes with DCC, which they also sell. It will be interesting to see where we go from here, because clearly, like it or not, sound is a BIG selling point. So far DCC isn’t close to being used by the majority of modellers, so it would seem to me that QSI is way ahead of the curve as far as making money goes. I can’t see any drawback to having a system that will work with DC or DCC. And, to me, a control pad like that offered by Atlas and BLI with buttons that match functions rather than having to remember all those CVs is another big plus, UNLESS one is into that sort of thing. If I sound like I am looking down my nose at the electronics whizzes, that is definitely not my intention. Twenty five years ago I would have been righ
Here is a great link to “DCC for Beginners” at Tony’s:
http://www.tonystrains.com/tonystips/dccprimer/index.htm
Should answer most of your questions.
I have the Digitrax Zephyr, myself. Love DCC, and would NEVER go back to DC !!!
Like Virginian, I clean my track only about one or twice a year, and only have two leads to my track. I don’t “memorize” CVs - my lights, horn and bell all work off buttons, marked as such, on either my Zephyr control panel or my remote UT1 throttle. When doing intial setup of a loco, I look up the CVs I need to change, read the value I need (or try a few to see what effect I like), set it and forget it !! Like DC, DCC can be as easy or as difficult as you make it !!!
DCC is more than sound - it is control of the locomotive! You can turn lights on or off (and have full bright on even when stopped, if you wish), have one loco in motion while another on the same track is stopped or going at a different speed, adjust the locos speed to match another loco in a MU train, and much more !!!
Please look over the Tony’s DCC guide for a better idea of what DCC can do for you. Then don’t be afraid to jump in - the water’s fine !!!
For a beginner DCC is probably the most intimidating aspect to model railroading there is, it was for me. Read all you can about it and you will soon realize it is very simple. Go to a club and some shows and talk to the guys that are running the layouts. DCC is for me anyways, the only way to run trains.
Thanks everyone. The advice and the links are a great place to start.
Shaggymojo, If you want to really get into the nitty gritty of DCC, including the best way to wire it (wiring is much simpler in DCC) take a look at Allan Gartner’s site: http://www.wiringfordcc.com/ The only recomendation I disagree with is the light bulb trick. I would rather have the block shut down than still have a couple amps of power going through fine wires when there is a short.
DCC is really thee way to go. Soooooo much more fun than fighting DC!
Ray:
Aw, contraire on the light bulbs!
While we can debate the theory of the light bulb trick all day long, the fact that it’s a low-tech solution, yada, yada … the practical reality is they work very well to control and manage shorts on a DCC layout, and they’re only a dollar each!
A more sophisticated solution like Tony’s Power Shield will cost you $30 per block, which can add up in a hurry on a layout of any size.
To see the light bulbs in action, here’s a video clip:
Any modern DCC system will shut itself down in case of a short.
I’m working my way back into MRR’ing - last time I was involved, DCC was for people who wanted to spend $750 or so to get a system. Actually - it wasn’t even DCC - it was one of its predecessors.
This new stuff (DCC) seems pretty cool. For around $200 you’re in. I think my most recent MRC DC power pack was like $70 or so. Those two numbers aren’t very far apart at all, considering what you get with DCC.
I have to admit, there are definately times where I think DCC looks complicated. I’ll read about how people are still creating blocks, worring about shorts, etc., and it seems at those moments that maybe it’s not much better than DC.
Then, to convince myself otherwise, all I have to do is open up Linn Westcott’s book on wiring your model railroad (my Dad must have bought it ages ago, and I ended up with it).
Wow - doing anything tricky in DC is pretty tough. Once you try to reach any level of sophistication (i.e., running 2 trains at once), things seem to get very complex very quickly. Although I can understand all the wiring, etc. (I’m a mechanical engineer), I’m pretty sure nobody but me would be able to operate a 2-cab control layout. (When I say nobody but me, I mean friends (other than engineering friends who would dig it), wife, niece & nephew, etc.).
Someone’s analogy above about old computers and current computers is a good one. In the past, the tech junkies could use computers. Today, many more people can.
I plan on building a very small shelf layout within the next year or so. I’m pretty sure I’m going to go with DCC. At the bare minimum, I’ll wire it with DCC in mind.
Bottom line for me: more than 1 train running, I want DCC. I tried 2-cab control on a small layout when I was a kid - in the end, only one person (my Dad or me) would run trains at once. Flipping all the electrical switches was simply not fun. So we had this small layout chopped up into a bunch of blocks and just ended up running it as
gb:
That, in a nutshell, is the problem.
Shutting down the layout when you get a short is not only very annoying to other operators when you are trying to have a realistic op session, the power spikes can scramble decoders, and damage equipment.
Worse yet, with modern high-inrush current sound decoders (QSI are the worst of the lot), the DCC system senses the high inrush current going to the sound decoders upon reset and immediately powers the layout back down.
The end result of the short with sound decoder locos on the track can be upon the first short the layout goes down, and WONT COME BACK UP AGAIN until you remove the sound locos from the track.
The light bulbs solve all these issues for a few bucks. They immedately limit any short to a max of about 2 amps (instead of the full current potential of your DCC system) and THEY become the load in the circuit.
The result is you get a short, the bulb lights up, and the DCC system does not shut down. Sound decoder equipped locos are not a problem because the layout never goes down from the short.
In fact, with some clever wiring tricks using the light bulbs, you can make it so only the train causing the short stops and all the other trains on your DCC layout keep running.
I’ve installed the 1156 auto tail light bulbs on my large HO layout and it has made having an op session on the layout with DCC into a dream come true. No longer does the layout shut down … things just keep right on running shorts or not. The bulbs limit the current so nothing gets damaged. And all for $1 a bulb.
It’s hard to imagine a better solution for the money on a DCC layout.
Shaggymojo…DCC is the way to go. It is so much more fun than DC. I was like the Virginian when I got back into MR.3 years ago. I put together a setup for DC,(2 cabs, blocks etc.)Wires all over the place. At my wife’s urging to get modern and help from the LHS I went DCC. It is not complicated. I use a Digitraxx Zephyr system. There is no need to memorize CV’s etc. The instruction book and code sheets for each decoder does it for you. I now run four trains at a time on my 4X8 layout easily. Try it you will like it . [:D]
Joe, (or anyone else): I’m speaking with no DCC experience (other than seeing a layout short time after time on a modular layout at a train show).
What causes the shorts other than:
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Derailing
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Running a train into a turnout not thrown the correct way for the train
Are there any other circumstances that cause shorts?
I’m trying to figure out if I’d need to worry about short protection on a very small layout or if the DCC power pack short protection would be adequate.
CARRfan:
90% of shorts will be caused by the issues you list.
The other reasons include:
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Reversing loops and wyes having the wrong polarity
-
Rail expansion causing gaps to close (most common source of “mystery shorts”)
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Metal tool or object accidentally laid across the rails
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Wiring boo-boo (missing gaps or incorrect wire connection – typically found after a wiring session is over [B)])
All my shorts have been due to the two circumstances you list.
IMHO, my Zephyr’s short protection is all I need on my home layout. It seems to work just fine, and I have yet to see any damage or decoder “scramble” or reset problems due to a short.
Joe’s solution sounds great for a large home or club layout, but IMHO is overkill for a smaller home layout that has usually only one and sometimes two operators. Usually, due to the nature of the short (derailing - on or off a turnout), I have to remove and re-rail the loco anyway !!!
My point exactly! I have heard horror stories of melted engines and fires, etc. I go with the recomendations of the manufacturers. You can do whatever you want… It’s your layout…
It sounds as if there is a “hole” in the design/application of DCC.
That is, shorts shutting down the entire system. It sounds like Joe (or whoever he got the lightbulb trick from if not his own design) figured out a work-around.
In these days of off-the-shelf products, etc., the thought of a work-around sounds crazy sometimes. But if you look at all the nested wire under a huge DC club layout (I’ve seen the wiring under a HUGE club layout - WOW), you realize with DC, everything WAS a workaround! It was all Do-it-yourself.
The light bulb thing seems to me like a trick for those who understand what’s going on with the electronics. If I researched it, (including drawing out a schematic to fully understand it then I might go for it if the need arose.
But since I’ll be running a small operation, it sounds as if I might be able to just use the DCC power pack short protection.
It almost seems as if DCC usage could be broken up into a few different categories:
DCC for sound:
DCC for large layouts
DCC for signaling operation
DCC for computer control
etc.
Then, of course, many of these categories will overlap for some people (maybe me? - I don’t know yet)
Pardon me while I’m thinking out loud and trying to wrap my brain around DCC (and hopefully encouraging others to think about this stuff as well).
What causes decoders to fry and let the smoke out, other than a bad wiring job?
I would agree that for a small layout, the light bulb may be overkill – the short protection of the DCC system is probably enough.
However, upon rare occasions, a short will sometimes fry a decoder. This is very rare, I’ve probably seen two cases of this happening in 12 years of using DCC on my layout and running regular operating sessions, plus several hours of layout staging or equipment testing per month.
More frequently, but also somewhat rare, you will get a scrambled decoder as a result of it being involved in a short. You will need to reset the decoder and reload all your settings. I’ve seen perhaps a dozen or so cases of scrambled decoders from a short in 12 years of using DCC.
With the light bulbs doing short protection, the short never really occurs. As far as everything is concerned when what should be a short occurs, there is a sudden 2 amp load that comes, and then goes once the cause of the would-be-short is removed. But NO short.
Since the installation of the light bulbs on my Siskiyou Line track feeders in 2000, all incidents of scrambled decoders (and even more rare fried decoders) have ceased. I can’t think of one time when we’ve lost a decoder (scrambled or fried) as a result of a short since 2000.
I suspect it’s because of the light bulbs. A true short is a very disruptive incident electronically. And the light bulbs smooth out things so the short is no longer disruptive.
It’s as if a short is a “bridge out” situation on the road, but the light bulbs turn it into a chuckhole. For myself, the extra wiring in not that hard, and the cost certainly isn’t an issue. And the protection the bulbs give is worth every penny, even to the point of saving decoders, in my experience.