I have a new Atlas Classic GP7 with a circuit board that includes an eight-pin socket for a DCC decoder. If I have a decoder with the correct 8 pin socket, can I simple plug this in and run the GP7? I am concerned about the existing rail connections to the motor. In previous installs, I had to manually isolate the motor. Does the the use of the 8-pin connection somehow isolate the decoder from direct AC track voltage? I have an old Digitrx DH83 with wire leads. If I only wire this to an 8-pin male socket and plug it into the existing female socket will I be okay?
Anthony
Most engines built after about 1995-2000 have the motor already isolated. Any engine with a DCC socket is going to have an isolated motor and is "plug and play". You can just plug in a DCC decoder of your choice and you're set to go. If you want, you can remove the lightboard and install a "drop-in" lightboard-shaped decoder.
Most locos nowadays list on the box whether they're "DCC ready" or not. Trouble is that term was used in the past to mean a lot of different things and not all included the wiring as ready for a decoder install. There are several sites around the internet that list various locos and indicate what's required beyond simply plug-and-play. Here's a couple as examples. You can find others with a little searching:
http://www.mrdccu.com/install/hods/index.htm
http://www.mrdccu.com/install/hoss/index.htm
This one is particularly good in the detail it gives you in order to assess yourself whether the wiring is ready for a decoder:
http://www.wiringfordcc.com/locos.htm
http://www.wiringfordcc.com/write_ups.htm
Mike Lehman
Urbana, IL
Anthony,
I have three of the Atlas Classic GP7's, and have installed Digitrax DZ123PS's in all of them, because that's what I had on-hand at the time. They are definitely good runners.
The 8-pin socket in and of itself doesn't isolate anything, it's how the overall electrical characteristics of the loco (including the 8-pin socket) are designed and implemented that makes the difference. But those Classic GP7's are truly "Plug 'n' Play", all you need to do is be sure you have the 8-pin plug oriented properly (the pin with the orange wire on the plug goes to the socket position marked with an arrow on the light board.)
The DZ123PS has been replaced by the DZ125PS since I did mine, and that's still a good choice, as is the DN135PS.
The DH83 is a very old decoder that lacks modern features, and with a 2-amp continuous motor rating it's over-kill for that Classic GP7. Having said that, yes, if you properly solder on an 8-pin plug it will work, although it might be a tight fit in the GP7.
Stevert: Thank you for the information and suggestions. I will be installing a Soundtraxx MC2H104OP. It is a plug and play decoder with an 8-pin male connector.
Athony
Stevert Anthony, I have three of the Atlas Classic GP7's, and have installed Digitrax DZ123PS's in all of them, because that's what I had on-hand at the time. They are definitely good runners. The DZ123PS has been replaced by the DZ125PS since I did mine, and that's still a good choice, as is the DN135PS.
Why did you select the DZ version over the DN version? I just acquired an Atlas GP7 and want to install a non-sound decoder. Looking forward to your comments.
Rich
Alton Junction
richhotrain Stevert Anthony, I have three of the Atlas Classic GP7's, and have installed Digitrax DZ123PS's in all of them, because that's what I had on-hand at the time. They are definitely good runners. The DZ123PS has been replaced by the DZ125PS since I did mine, and that's still a good choice, as is the DN135PS. Sorry to revive an old thread, but I am hoping that Stevert sees this post. Why did you select the DZ version over the DN version? I just acquired an Atlas GP7 and want to install a non-sound decoder. Looking forward to your comments. Rich
Sorry to revive an old thread, but I am hoping that Stevert sees this post.
Answers in his post. Highlighted by me. Steve may be like me - I have a few decoders in a drawer most all of the time so if i want to install one I don't have to wait. Though in my case they are always just plain wire decoders without plugs because I pretty much never plug in to a factory board.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
If I remember right, our dear departed friend Jeffery W. used DZ decoders because of it's size, making it easier to fit into a shell.
Mike.
My You Tube
So, let me ask this.
If you use the DZ decoder in an HO scale locomotive, do you give up some power or is the result the same as a DN decoder or the full size HO scale decoder?
Zero difference in performance. Usually what you lose with the smaller decoder is total motor drive power. The Z version may be good to only 1 amp where an HO one might be 2 amps. Same firmware and features in both. Z scale may have fewer function outputs, but what it has will have all the effects of the same range HO decoder - you won't lose for example Rule 17 lighting just because the Z scale decoder is smaller, but there may be only a total of 4 functions on the Z decoder while the HO has 6.
rrinker Zero difference in performance. Usually what you lose with the smaller decoder is total motor drive power. The Z version may be good to only 1 amp where an HO one might be 2 amps.
Zero difference in performance. Usually what you lose with the smaller decoder is total motor drive power. The Z version may be good to only 1 amp where an HO one might be 2 amps.
richhotrain rrinker Zero difference in performance. Usually what you lose with the smaller decoder is total motor drive power. The Z version may be good to only 1 amp where an HO one might be 2 amps. When you say total motor drive power, do you mean that a DZ decoder will run slower than a DN or DH decoder? Rich
When you say total motor drive power, do you mean that a DZ decoder will run slower than a DN or DH decoder?
Just now saw this. Randy is correct, those are the ones I had handy at that point in time.
As for the "lower motor power", the DZ's usually have a lower max current rating than the DN's or DH's. As Randy mentioned, a max of 1 amp motor current vs. a max of 1.5 or 2 amps in a larger DN* or DH* decoder.
But the Atlas locos have a pretty low current draw, so that lower max never comes into play.
No, the voltage is exactly the same. I mean current, like Steve mentioned. 1 amp or so for the Z scale decoders vs the 1.5 or 2 amp peak for the HO. As long as the motor draws below the decoder current, you can use it, and it will run the same speed compared to putting in the HO version of the decoder.
On some smaller locos you might not have a choice, you may need the Z scale decoder for space reasons - like one of those little EMD Model 40's, or the new Walthers Plymouth switcher - or the BLI Trackmobiles.
Calling a decoder a specific 'scale' decoder is sort of a misnomer, other than board replacement types common to N scale (since there is seldom much room - and different locos have completely different layouts for the boards) there is no real electrical difference that would make one decoder a "Z scale" decoder and another an "HO Scale" decoder - it's all just size.
rrinker No, the voltage is exactly the same. I mean current, like Steve mentioned. 1 amp or so for the Z scale decoders vs the 1.5 or 2 amp peak for the HO. As long as the motor draws below the decoder current, you can use it, and it will run the same speed compared to putting in the HO version of the decoder.
Stevert Just now saw this. Randy is correct, those are the ones I had handy at that point in time. As for the "lower motor power", the DZ's usually have a lower max current rating than the DN's or DH's. As Randy mentioned, a max of 1 amp motor current vs. a max of 1.5 or 2 amps in a larger DN* or DH* decoder. But the Atlas locos have a pretty low current draw, so that lower max never comes into play.
Same question that I asked Randy. My RRampMeter indicates that none of my locos even reach 1 amp, so current consumption seems to become a non-issue. Is this correct?
Yes.
You're overthinking it. Forget they ever called it a "Z scale" decoder just because it's physically small. Electrically it is EXACTLY the same as one called an "HO scale" decoder. It's no different than Tsunami vs Micro Tsunami or Loksound Select vs Loksound Select Micro. Same decoder, different size.
You do need to remember that DC motors don;t have A current draw. There is a free-running current, such as if you hold the motor in your hand and connect power, nothing physically attached - no gears, etc. As you increase the load on the motor, the current draw goes up, until you hit a point where the motor does not have enough power to turn the shaft - this is the stall current. This is what you need to check before selecting a decoder - the decoder must have a current rating equal or greater than the stall current to avoid any chance of overloading it. The rrampmeter may show less than 1 amp while the loco is running around the layout pulling a train but moving freely - the wuestion is what the motor draws if it becomes stalled and can;t turn. You don;t test that with a decoder already installed, you test that under DC before putting in the decoder.
Other than the maximum current the decoder can handle, there is no other difference beisdes physical size. Current capacity does not determine speed, the voltage does. And side by side on the same DCC track, a "z scale" decoer will apply the same voltage to the motor wires as an "ho scale" decoder or an "n scale" decoder or even an "o scale" decoder for a given speed step (assuming you haven't configured speed tables). The same motor tested across all 4 decoders will turn at the same RPM at the same speed step.
OK, thanks, Randy. That helps a lot.
Sometimes it helps (and sometimes it doesn't) to think of it like water.
Say you're doing plumbing and you need a pipe to carry X gallons of water per minute through it. You try it with a 2" pipe, and it works fine - but the pipe is less than half full when you put the water through it. So you try a 1" pipe, and it works fine, but since it's smaller it's about 3/4 full. If you tried substituting a 1/2" pipe, there wouldn't be enough capacity to do the X gals per minute of water.
Similarly, say you have an HO engine who's motor at max draws .8 amps. You could use a 2 amp decoder, but a smaller 1 amp decoder would work too, as your motor draws less than 1 amp. Both decoders take in 14V AC power from the track and convert it to 0-12 volts DC to run the motor, so the top speed etc. should be the same with either decoder.
Thanks, Stix.