I have just recently upgraded from DC operation to DCC (Digitrax Zephyr Xtra). The main thing that I notice is that my locos all run about half the speed on DCC at full throttle than they did on DC at full throttle. I have checked my speed setting on my Zephyr and it is set to SP99. At full speed, my trains would not stay on the track on DC, now they can run all day at top speed and seem almost slow.
Am I missing something? Will gladly provide more details if needed.
Thanks in advance.
If it's truly half, check the voltage on your track. Use the AC mode, it's cloe enough. It should be around 12 volts. Or measure from Rail A to Ground and Rail B to ground - they should be the same. If they are not, which I suspect is the issue, first select address 00 and make sure to set the speed to stop and the direction to brake. Repeat the measurement, if it still differs, there's a problem with the Zephyr and it needs repair.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Are you comparing the same loco on DC to its performance when a decoder has been installed and it is on DCC?
What decoders have been installed?
What are you using as the DC power pack? What is its track voltage? It may be that your DC pack has a higher voltage and therefore runs the locomotives fast. I suspect you will find that the locos top speed is now more prototypical.
Simon Modelling CB&Q and Wabash See my slowly evolving layout on my picturetrail site http://www.picturetrail.com/simontrains and our videos at http://www.youtube.com/user/MrCrispybake?feature=mhum
Many DC powerpacks output over 12 volts, so you can check the voltage out of the old one under load(with a loco running) and compare with the DCC. I had about 18 volts DC and went to 13 volts with DCC, so I turned up the voltage on my Digitrax to 16--no problems in years. Also, if your locos went from having none to using a DCC decoder that will cause a slow down too since the decoder itself uses up some energy.
BTW, it's interesting how some locos today can't get up to prototype speeds, like this months MRR pointed out about the new Zephyr. I am in the process of remotoring a P42 so it can get up to speed.
Richard
Have you tried calculating what the actual sMPH of your locomotive is on DCC? It might just be that you are so used to "bullet train" mode on DC that anything is going to seem slow.
Your locomotive may be operating at prototype speed. Hard numbers would actually confirm that or not.
Tom
https://tstage9.wixsite.com/nyc-modeling
Time...It marches on...without ever turning around to see if anyone is even keeping in step.
Use the below link to do real world measurements. Compare between DC and DCC.
http://home.cogeco.ca/~trains/rroperat.htm
Rich
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.
Yup it's one of the first things I noticed when I went to DCC. Now with a little understanding (just a bit) I think I figured it out. The first thing is in the Decoder, takes a bit of current to keep it happy even though you may run it on analog. The most important of all and I mean no insult to you is that when we were younger in model trains they should have warp speed and probably my fastest runner was doing 200 mph if measured ho scale speed! Hate to think of a prototypical steam loco going that fast and wrecking. The wreck of old '97 (90mph) would look like a simple derailment by comparison! No I kind of like it slower now that I'm matured and older, birthday yesterday 68. I really enjoy being able to just crawl at 3 mph, barely moving, which couldn't be done with them old pancake motors of yesterday. If I want warp speed I'd probably go back to DC or slot cars. Not today enjoying the modern DCC stuff more than I ever did, it's all good from the cheapo Bachmann EZ DCC up to the best system money can buy. Jim
I got out my volt meter and tested a bunch of things. Track voltage on my DCC is about 7 volts. On prior DC it was about 17 volts. You mentioned that you turned up the voltage on your Digitrax to 16. How do you do that? I have read my manuals but no where does it describe how to change the track voltage. Only thing that it says is that you should have the output voltage (to track) about 0.5 volts less than the input voltage (14 volts in my case).
Calculated the prototype speed. At full throttle it is 63mph. I would be willing to bet that the full throttle speed of most modern diesels is faster than that. I want to enjoy a little risk in my life (I live on the edge, don't ya know).
I enjoyed the calculator. Got out my measuring tape and stopwatch. Top end is 63mph (yawn).
I am only 56 1/2 so I am looking for a little more excitement. Calculated my prototypical speed at full throttle to be 63mph. I am warming up, though, to having the precise control at slow speeds, but I need some mainline excitement too.
Zephyr's track voltage?
Use and AC meter, measure between Rail A and Rail B. Measurement will be approximate but close enough. If using a DC meter, measure the voltage between Rail A and Ground. Measure the voltage between Rail B and ground. Add the two measurements together to get the actual track voltage. 7 volts is too low. Zephyr should be putting out between 13.8 and 14 volts to the track if you are using the Digitrax power supply.
Voltage is not adjustable on a Zephyr. It's adjustable on the Empire Builder (DB150) and Chief (DCS100) sets. DCC will normally run slower then DC powered track. The reasons have already been pointed out. What the heck, DCC is supposed to be a more prototypical way of running trains. Top speed goes with that.
Martin Myers
57 1/2
Old Red Caboose I got out my volt meter and tested a bunch of things. Track voltage on my DCC is about 7 volts. On prior DC it was about 17 volts.
I got out my volt meter and tested a bunch of things. Track voltage on my DCC is about 7 volts. On prior DC it was about 17 volts.
Doesn't the Zephyr have an N - HO switch on it for operating it in either mode? If so, would the output voltage be less for N?
63 MPH might be slightly slow for a modern diesel locomotive but I don't think a prototype would commonly go more than 80 MPH pulling a load - unless you are out west somewhere on a long straight section of track.
And, just for comparison, you might try running one of your non-DCC locomotives on full-throttle DC to see what sMPH you were running them at before converting them to DCC. Your thrill rides might have easily been in the 120-150 MPH range. At that speed, even 70 MPH would feel like a death crawl.
No, no voltage selector on Zephyr, it's fixed at approximately 12.5 volts so it's good for all scales (well, G perhaps not...but then the power is a bit low for G scale anyway)
DB150 and DCS100 have switches to set N (12V), HO (15V) and O/G(18V), assuming you are using an appropriate power supply - a 15V power supply cannot make 18V on the output.
ANd if that is 7V rail A to ground, and rail B to ground is the same, it;s OK. But it it's 7V AC across the rails, then half of the track driver H bridge is blown and the unit needs a Florida vacation. If it's 7V DC across the rails - you have address 00 selected and set for a non-zero speed.
Another thought I got about warp speeds. Years ago when a loco derailed and hit the floor, even if part of the shell broke, it still ran, maybe the light didn't work anymore, not much inside on whatever light board they might have. Most of my old stuff from the 60's-70's didn't even have a light board. $10-20 dollar loco's. Now today with my most expensive loco at $400.00 on down to yea even my $50.00 loco's I wouldn't like it if it just derailed and rolled over let alone falling on the floor. What with the electronics on the light boards and decoders, which seem fragile on the inside and the tight fit with just a piece of cellophane kapton tape keeping it from shorting out. I imagine a jolt from falling would destroy it soon as you put it back on the track with the power on if the decoder shorted out it would be toast. And of course the fragile detail parts loco's have today on the outside. Well for me they're just to nice to abuse intentionally in such a way. I'll stay within the scale speeds for me. Jim
Seven volts is way too low, so your problem is in your power supply.
Once you fix the voltage problem, reconsider your desire to run trains at warp speeds so that they nearly leave the tracks. It simply isn't prototypical.
If you really want to run trains at warp speeds, get an 18 volt AC transformer and some O gauge or S gauge stuff. Nothing wrong with it, but your desire is to "play with toy trains", not to model prototypical operations which is what "model railroading" is all about.
Alton Junction
I came accross this thread trying to figure out what is happening to the speed of my locomtives as well.
I did want to comment on the high speed running of your layout;
There is nothing wrong with running your trains at high speed so long (and this is just preference/opinion) the railroad you are attempting to mimic operates at those speeds as well.
In my case I model the NEC future as best I can within my means. As such, I require max speeds ranging from 125 - 150 MPH. My computer carries out my operating sessions and adjusts the trains' speeds based on its scale location along the corridor so there will be station approaches where the train is at a crawl and other stretches where the train is at "warp speed". I like the dynamic! The computer also calculates/estimates the speeds so I've been able to get fairly accurate readings.
None of my equipment with the exception of my Atlas AEM7s have come close to operating at their prototypical max speeds under DCC (110 MPH at one time). This was not an issue for DC as others have noted.
Some have suggested it is the decoder and that's what I suspect as well at this point. My AEM7AC's are the fastest running locos out of all of them including the Acela (go figure!). The AEM7ACs are currently using Digitrax DN136 decoders which I noticed, have a lower current rating than the TCS decoders in my HHP-8s (the slowest running except for one which tops out at 90 MPH on a good day).
~Kyle
The Mary Lindsay Railroad - Featuring Amtrak Model Trains Your HO Rail Journey Starts Here.........
www.marylindsayrr.vze.com (Last Update: 5/31/12)
It's not the current rating, but more likely the BEMF implementation. Try completely turning off the BEMF and seeing if the HHP-8's go faster.
For the Zephyr Xtra, the output voltage is based on the power supply input voltage, the supplied system keeps it at about 12.5 volts, so less voltage gets to the motor than a typical DC power pack - which often put well voer 12 volts to the rails, especially under a light load of just 1 or 2 locos. 12.5V DCC on the rails will result in under 11V peak to the motor under the best of conditions, due to junction drops at the drive transistors, among other things. A slightly higher voltage power supply (do not exceed the maximum marked on the unit) will put a slightly higher voltage on the rails. The bigger systems like the DB150 and DCS100 put 15V DCC on the rails in the HO setting, which results in more than 12V to the motor at full throttle, just like DC.
When I switched from a Digitrax Super Chief DCC system to a NCE Power Pro system, there was a noticeable increase in engine speed. Both systems were using the same power supply.
The NCE system applies 13.2 Volts to the track.
SouthPenn When I switched from a Digitrax Super Chief DCC system to a NCE Power Pro system, there was a noticeable increase in engine speed. Both systems were using the same power supply. The NCE system applies 13.2 Volts to the track.
Ignore this. thought I had something but testing proved I didn't. #7 function key can slow down or speed up my BLI T-1's but after checking other locos it doesn't affect them at all.
If you had the DCS100 set to N scale, it only puts 12V on the rail. The HO setting puts out 15V. Unless of course you were only using a care battery eliminator power supply - usually 13.8V DC. Digitrax boosters work on AC or DC< as such there is a rectifier bridge directly inside the power input terminals. With a DC power supply that will drop you 2 diode drops right off the bat, about 1.4V, so with a 13.8V input you'd be down to 12.4V. Add in the drive circuitry and you probbaly have less than 12V to the rails no matter what the setting of the scale toggle. There's a reason the instructions specify a 15V AC power supply for all but the O/G scale setting (which is about 20V to the rails - not going to get 20V out with a 15V input)