Couple of DCC problems

I'm starting to have a couple of problems. I think I've narrowed it down to something going wrong with my system (I use the NCE power cab.)

I have noticed that here lately it seems that everything is sucking down more juice and it's causing light problems. On lights that use to work just fine now act like the resistor value is too high.

And then the big problem. Every time I try to reprogram the speed table on a loco it becomes all or nothing on the speed (SS 0 not moving, SS 1-28 full speed ahead.) And it does it on ALL of my loco's, regardless of the decoder make or model.

What can I do here? I have tried doing a factory reset on the cab, that didn't fix it. And the speed steps work just fine on he decoders after a factory reset on them, but when I change em it's right back to square one.

Ethan

 

I'd ask your question on the NCE Yahoo Group.

 

Ethan:

Have you tried doing a complete system reset. I am talking about your system itself, not individual locomotive decoders. I don't think it can do any harm.

 

Bob, that is what I meant by doing a reset on the cab. I guess I could try it again.

Ethan

 

Ethan,
I think the problem you are describing is a bad rheostat (throttle knob) in the power pack or walk around throttle. If you ever opened up an old DC power supply you would see a metal "wiper" that slides across a coil of very fine wire. This acts as a resistor to current and gradually allows voltage to build up which allows the locomotive to move. It is called a "Rheostat" and it sounds to me that it has went bad on you. Now if you are electronically inclined and experienced with a digital voltmeter then you could do some trouble shooting yourself and look for an above normal (more than 16 V DC) voltage reading on the output of the throttle when you power up a loco. I would bet you have a bad throttle device. Only other possibility I can think of is a short in the wiring somewhere on the layout, but if it happens on reprogramming I would say a bad throttle.
George
FriscoGeorge

 

Ethan,

I installed a Soundtraxx mobile decoder and it ran at only one speed, about 80 mph. Keith disabled back EMF and now it works great. You might try that.

 

I think I will try Rick's idea. How do I disable BEMF?

George, I understand what you are saying. But the cab has three different ways to control speed so I doubt that is the problem. It has two different buttons for speed and a knob, but it has been messed up for a while, and it's something broke physically, but electronically.

 

Ethan,

Are you programming through DecoderPro or through your NCE system? If DecoderPro (HEY this would be a great clinic at the next Frisco Meet. HINT), I can get you the steps. If through your system we can do that too but, either way, we will need to know eaxactly what kind of decoder you are using. There should be documentation with it (I should be able to get that on the website too) that will point to the CV that will need to be changed and what value will disable the BEMF. Sooooo let me know the decoder and we can get started to see if that is the problem. Not a bad idea to discuss this through the website so we can all figure it out and learn.

 

If I understand Ethan's first post correctly, this doesn't sound like a decoder problem to me. If this were just one loco it would likely be a decoder problem.
Ethan, the first thing I would suggest you do is remove all locomotives except one from your layout. I would also remove anything you may have lying on it also. Then see if the locomotive acts correctly. If you still have a problem then isolate sections of you layout to see if you might have an electrical problem in a section of it. If you are not able to break your layout into sections I highly reccomenned you do this sometime in the future.
I have a gut feeling that maybe you are trying to draw more current than your system is able to supply but without knowing a little more information I am not totally sure. I am not real knowledgeable with your system. Do you have a seperate power booster or is your system all in the throttle. A little more info from you would be helpful, and as Richard has suggested going to the NCE Yahoo group is a great way to learn about your system and DCC in General.
Hope this helps.
Bob Wintle

 

Ethan:

After going to the NCE site and looking at your system (Power Cab, is that correct?) I agree with both Bob and Keith's assessment 100%. You have a 2 amp system and according to NCE's explanation, this is how they advertise it. "This 2 Amp system can operate 2 or 3 HO sized trains, or 4 N scale trains". I honestly could say that they are probably referring to non-sound equipped locos and even one with sound, especially if it's QSI, will really sap your system capacity.

It looks NCE makes a 5 amp Smart Booster designed specifically for your system called the SB3a. You will probably also need to purchase a power supply for it but I would follow Bob Wintle's advice first and see if this is indeed your issue.

http://www.ncedcc.com/component/vir...ypage=flypage.tpl&product_id=97&category_id=1
http://www.ncedcc.com/component/vir...etails&product_id=3&flypage=flypage.tpl&pop=0

On both this page and the one for your system there is an "ASK A QUESTION" button and I would highly suggest taking advantage of it. Hope this helps. Please let us all know what you find out.

 

Ethan could check this out quite easily by taking all of his engines off of the layout and trying it with one locomotive, then two, then three, etc.

My understanding is that non-sound decoders hardly draw any amps at all. Am I misinformed?

 

At rest the non sound decoders don't draw much current. Add to that lighting and the motors when running and that is where you begin to add up current draw rather quickly. If you are using incandescent bulbs for lighting rather than LED's the current drawn adds up that much faster.
I am very proud that Ethan has learned as much as he has about DCC and Model Railroading. Keep up the good work Ethan!
Bob Wintle

 

Ok, were to start...............

My power cab isn't really a box like the zephyr. How to describe it. It's kinda like your digi trax stuff, a loconet (NCE doesn't call it that) panel and a throttle with a power supply plugging into the board. Yes it runs 2 amps, and the 2 to 3 is an under statement. I have ran 4 locos all at the same time before (it was a couple years ago, I've had this system since may of 09) all silent, all with as many lights on as possible. No problems at all. I have tried some more trouble shooting with all but one loco off the track. So loco's setting on the track cant be an issue.

I have looked at the smart booster before, I know about it. It's something I want to get but just havent yet and yes you do have to buy a seperate 5 amp power supply.

I am programming with the system. I don't have decoder pro. Yet again another thing I want but don't have.... yet. Thinking about getting it so maybe I can resolve these issues. After watching some videos on youtube I gotta say programming on the power cab is so much easier than a zephyr, and different two. I normally use program on the main. But at the recommendation of some one on a different forum (I know most of the people on here are digitrax so I thought maybe some one would know if it was a common system problem) I took all the loco's (cars are still on the track) off except for one to program and used programming track, but still no luck.

I don't have any sound loco's. I will when the U30B's show up...... if they do.

Here is the list of the decoders I have installed in loco's:

TCS brand:
A4X
A6X
T6X
T1

NCE brand:
D13SR
D14SR
D15SR
N12SR

Sorry for the long post

Ethan

PS I want to thank every body who has taken the time to post on this and help me.

 

Just looked at your system on line. The power supply for your system looks to be what I call a wall wart. When you are having this problem is this item warm to the touch?
Have you taken every car, all tools scenery supplies and in general clutter off the layout. There could be an item barely touching somewhere? have you made any changes to the layout recently? Sometimes something simple you may have done to the layout can cause a problem and can be easily overlooked.
Let us know if your wall wart power supply is hot or not. It should be slightly warm but not hot.
Hope this helps, I am trying to think of everything I can to be of help.
Bob

 

Bob, I'll have to check tool and the power supply, I don't ever recall it being warm. Now that I think about it I did install a new track section. Just a simple straight of flex track. I don't see how that could cause problems but I'll try cutting off the current to that section. Now is it was a short then I would know because the power cab alerts me. It's a little different than what the zephyr does. The track power light dims and so does the back light on the cab and there is a buzzing noise.

And a short doesn't make since. If it doesn't work after I reprogram it, then why does it work after a factory reset.

Ethan

EDIT
I put in a test track with a on off switch a while back. I can't remember if it started acting up after that or not though.

 

Your power supply for a NCE system is not a power supply but a 5 or 10 amp 16 volt ac transformer; you can purchase the PS515, i think it is called from NCE, or do as I did, and get the Magmun Force from Tony's exchange for you NCE system, and it is not a wall wart Like you present 2 amp system.

 

Finally got around to working on the problem a little bit (busy high school schedule. swamped this week, nothing the next....). I unhooked the new section of track, then proceeded to factory reset and then reprogram my SD40-2 which has a A4X decoder in it. The first speed table I wasn't sure if it was working or not. It was running pretty fast so I kicked it down a bit and it works just fine on the new speed settings. Then I put my B30-7 on the track, which has a NCE D14SR in it, and did the reset and the default table is VERY slow, so I reprogrammed it and it's still slow (need to kick the volts up) but as far as I can tell it is all or nothing. Just FYI I am doing this on the programing track mode instead of the program on the main now, and I am setting Acceleration and Deceleration to 0. I have not disabled BEMF, but I may try it. And one more FYI I did not set any torque compression or kick rate settings, they are 0.

Ethan

 

AMEN!
Good old DC rheostats usually work every time unless they get corroded. I tried DCC and found it to finicky for my taste.
George