feedback controller and DCC

Hello,
I'm about to take delivery of my first DCC equiped loco. However, as I've not yet gone down the route of DCC I intend to run in off DC. I'm currently using a Pentroller
which uses feedback -- is this likely to fry the decoder? Would I be better off with a non feedback controller?
Many thanks,
Ashley.
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"Ashley Sanders" wrote

Try reading the instructions of the loco when it arrives! Some decoders facilitate use with conventional DC others don't.
John.
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I have a Lenz Set 100 and Mackay Models (who distribute Lenz) in the UK state that if you use a feedback controller you will fry the decoder (or words to that effect). If you wish to use the locomotive on feedback DC then remove the decoder and replace the link in the circuit board. However, if it is one of these continental DCC fitted jobs, this may not be possible. Bachmann, Hornby and Heljan (and others who produce foreign outline models) produce 'DCC ready' models. This simply means that the loco comes with a an internal circuit board with a link in a socket. You simply, remove the body, the link and plug the decoder in (the right way round and fitted with an eight pin etc plug). So I hope this info will be useful....take the plunge and go DCC you will not regret it! regards, Steve
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AIUI, "feedback" controllers ensure that the 'train's' speed is constant up hill and down. If so, what's the point?
I'd much rather have my train(s) operate as they do now. Slowing down for the up hill grades, and requiring me and my fellow operators to give them more 'throttle', and speeding up on the down hill grade requiring the operators to ease off on the 'throttle' in order to maintain a safe and realistic speed.
After all, isn't that what 'operation' is all about? If not, you may as well have a computer run your trains.
-- Cheers Roger T.
Home of the Great Eastern Railway http://www.highspeedplus.com/~rogertra /
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"Roger T." wrote

up
That's one angle, but I believe that a feedback controller will also give a little surge in power if it detects any hesitation in the motor thus potentially avoiding a stall.
Personally I'm happy with a non-feedback pure DC controller, but at some stage I'm going to have to take the DCC plunge.
John.
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On Mon, 05 Jul 2004 10:13:22 +0100, Ashley Sanders

You will be better off spending your money on a dcc controller, eg a Lenz Compact, rather than another DC controller, or stick to Plain old DC trains. Your Pentroller will not harm your decoder but may not run it very well as the feedback cannot work through a decoder. Keith Make friends in the hobby. Visit <http://www.grovenor.dsl.pipex.com/ Garratt photos for the big steam lovers.
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Keith Norgrove wrote:

Keith,
I agree with that. But, I'm not yet ready for going down the DCC route, though I will in the next couple of years.

I didn't have a choice in this case as the loco only comes DCC equipped.

Thanks for that and to all the others who replied.
Regards,
Ashley.
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Ashley Sanders wrote:

I disagree, DCC locks you into individual loco control rather than prototypical route control.

Run it on DC anyway. A feedback controller should just put out a voltage proportional to the knob position with a decoder fitted loco. A problem could possibly arise of the decoder can't cope with PWM DC output, but there shouldn't be a problem.

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Gregory Procter wrote:

Well I don't want to be locked into any way of working.
I don't see anything wrong with individual loco control.
There is no reason why DCC and "prototypical route control" cannot co-exist.
Ashley.
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Ashley Sanders wrote:

There's nothing wrong with it as such, but if you want to operate anything more intensive than a GWR single loco in steam branchline or a Big Boy hauling a train of fruit wagons across the desert you need block control of a layout.

True, but you will find that either you have to write your own computer program or you are stuck with whatever restricted non-prototypical facilities your DCC system allows.
Regards, Greg.P.
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"Gregory Procter"

What are you talking about? How many trains/locos can you operate at one time? Me? It's one at a time.
I may have up to four (Or more sometimes) trains/locos runing on my GER at any one time, but each train/loco is under the control of one operator.
For example, an operator brings a westbound through freight train to a stand on the Main Track at Granville Jct. The "switcher" operator pulls off the van (caboose), sets it onto the rear of the cut of westbound cars sitting on the Siding (Loop), goes back onto the train, pulls off the interchange (exchange) cars from the rear of the freight and sets them aside on Yard Track number one. He then goes goes onto the Siding (Passing Loop), grabs the departing westbound cut of interchange cars he'd set there earlier but now woth the van attached, and sets them onto the rear of the westbound through freight on the Main. Once this is done, he heads back into the yard to classify the cut of cars he's just lifted from the through freight and set out onto Track One.
While all of this is going on, the engineer of the through freight's 4-8-2 has uncoupled his loco and headed over to the the inbound lead at the roundhouse. As he's heading over to the roundhouse, the engineer of the 2-8-2, has, once the 4-8-2 is in the clear, come off the siding and backed onto the through freight ready to take it on westward.
The 2-8-2 was sitting on the other end of the Siding from which the yard switcher picked up the freight cars to be tagged onto the through freight.
This little operation all takes place at the same time, with up to three engines moving at once, with at least two of them on the same track at one time (the Siding), each loco under the control of its own engineer and without a single block toggle switch being thrown.
And oh yes, there's one or two other trains and or locos running elsewhere on the layout at the same time all the above is happening. None of these movements requires electrical block switches, nor do they require any "programming" other than the intitial "programming" of each locos operating attributes.
If I wanted to go further, I could also have the headlights working (I don't, because in steam days locos run with headlights "off"), I could have the bells ring when appropriate, and sound all the prototypical whistle signals involved in the above movements. All with no "programming".

Again, what are you talking about? DCC, computer programs? What are you going on about? There's "computer program" for DCC.
Do you have DCC installed? I think not, as you don't seem to have a clue what it's all about. Really.
The only "programming" is setting up the locos individual address and, if you wish, acceleration and deceleration tables, that's it.
Of course, you can "consist" locos. i.e. have them coupled together and controlled by from one cab, but again, that's not "computer programming".
Read the above description of an switching movement that takes place four times per "day" on my GER. twice each day, east and westbound.
Don't like North American? Then substitute the above for a UK passenger train dropping say a restaurant car and a couple of carriages, adding three extra carriages all while exchanging locos.
-- Cheers Roger T.
Home of the Great Eastern Railway http://www.highspeedplus.com/~rogertra /
-- Cheers Roger T.
Home of the Great Eastern Railway http://www.highspeedplus.com/~rogertra /
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"Roger T." wrote:

Double track mainline with through trains and suburban trains originating and terminating. Goods yard and loco depot with bankers for the incline. Mainline and staging yard for 19-20 trains automatically operated.
There can be as many as 5 train operations taking place at at any instant, but I drive only one at a time when I'm operating alone. Further operators can take over tasks from the computer.

Well, that's much like my layout operation.

Same here. Well, the limit is two independently operated locos on one siding, one at each end of the ladder.

I've almost eliminated block switches from my layout - the remaining ones relate to non prototypical electrical blocks to allow double heading locos to couple together. Block power is controlled by turnouts and signals. Cabs are logically linked by computer.

I operate headlights by raising the PWM voltage of traction current from 12 volts peak to 15 volts peak. Whistles will be from beneath baseboard speakers (someday)

Sure, but the computer programs lock you in to the operating proceedures of the writer, not your prototype.

Actually, yes. I have had DCC available since 1995. It works ok on my exhibition shunting layout and as a separate cab on my analogue layout.

Sure, but you're locked into the stupid terminology of "consisting".

When did the (UK) GER ever use the term "consisting"?

No problem in analogue.
Regards, Greg.P.
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"Gregory Procter"

but I

take
Bingo. You don't "operate". You run a manual train while the computer controls the rest. That, in my book, is not "operation". Operation uses humans to drive all the trains and engine movement.

at
[Snip descrition of one operation on my GER]

But can you attach and detach vehicles to your trains without the use of isolation blocks? I can. Can ypu have two, or more, engines running in one electrical in each direction? I can. And that happens on the prototype everyday.

one
siding,
But with you, are the locos both on exactly the same piece of track, between switches/points/turnouts and able to run opposed to each other, as they can on the prototype?

elsewhere
relate
couple
logically
Ah, ha. YOU use a computer to run trains. That's NOT operation (Well, except for perhaps use in automatic stageing yards) . That's automation. Not the same thing. On my layout, all trains are run by humans.

have
12
speakers
My locos could, if I wanted them to, have the sounds originating from the locos themselves. The headlights could be turned on, off or dimmed manually, etc., etc. just by using a DCC controlled on-board sound system. Something I've chosen not to do.

computer
you
of the

Sorry, my comment above should have read "There's _NO_ "computer program" for DCC.

clue
exhibition
programming".
"Consisting" is not stupid terminology. In North America, locos coupled together and operated from one cab are a "consist" and are refered to in the rule books as a "locomotive". As DCC was developed in the U.S. of A, as was the computer you're working on, your stuck with North American terminology, just as you are with your computer. :-)

four
Oh? Who mentioned the UK GER?

three
Yes it is. You cannot operate two locos, independently, on the same track, in opposing directions, with going to all sorts of electrical block trickery.
Cheers Roger T.
Home of the Great Eastern Railway http://www.highspeedplus.com/~rogertra /
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more intensive than a GWR single loco in steam branchline or a Big Boy hauling a train of fruit wagons across the desert you need block control of a layout.
Thats exactly the sort of reason why DCC was invented! So that you can easily operate trains without having to have blocks. Tell me what is prototypical about having blocks on a model railway, apart from the obvious signalling purposes. Even then there were so many exceptions it's not funny (station limits and banking locos for a start).

Absolute garbage. There are prewritten computer programs for both DC and DCC route control and signalling for a model railway. There is no need to write your own. As for non-prototypical, I might point out that DC is not particularly prototypical and to make it even vaguely prototypical you need to farnarkle around with blocks and power sections and isolation regions and if you really want prototypical operation for route control, then you'd include relays for interlocking and more electronics to make sure that nothing moves when it's not supposed to. Because I wanted to do all this without the electronics was the reason I went DCC in the first place!
I don't care that you think DCC is a waste of time Mr Procter, but if you're going to talk it down, at least be accurate and pick on it's true faults which at this stage is mainly the up front cost of the kit and the requirement for a decoder to be fitted in every loco you intend to run. In terms of "prototypical operation" either from a route control point of view or from the point of view of driving individual trains (something you think doesn't happen on the real thing based on your comments in this thread), DCC is a large improvement on increasing and decreasing power in sections of track.
To each their own, but I've seen fantastic layouts that are let down by complications in electronics in trying to achieve prototypical operation where DCC would be a major advantage in operation, the main inhibitor being the cost of conversion.
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Michael Walker wrote:

What more reason do you need to install signal blocks other than that the prototype uses them??? More to the point, signal blocks enable you to run multiple trains on the same main line, just like the prototype does. I know that with DCC you can run multiple trains on the same track in the manner that multiple cars/trucks can be driven on a motorway, but that's exactly where my analogy of slot cars comes in!

Well, you should be able to understand the reasons for those exceptions and deal with them/reproduce them in model form.

I'm not aware of any that operate as my prototype does and still allow for the compromises of model railway operation.

It's not the invisible bits I'm concerned about, it is the compromises the program forces me to make.

The only non-prototypical factor I need to farnarkle (lovely word!) around is uncouplers - they exist both in DC and DCC to the same degree and cause exactly the same compromises.

Sure, on this layout I've moved on from that point to including as much of the interlocking as possible in software form.

DCC doesn't provide any interlocking. The whole point of DCC is to provide a control system that ignores signalling.

I'm pleased about that! It's my personal opinion, which I sometimes feel the urge to mention when beginners start raving to beginners that it is the best thing since slot cars. :-)

I'm telling you that like all electronic equipment, it is great if you want to achieve results that are within it's limitations, but if you want to move beyond it's limitations then you're stuffed.

Come back to earth! Yes, I drive individual trains and it's great to be able to drive individual trains without the hastles of cabs, blocks and signals.
Once one starts to build a prototypical layout the signals and their operation become an important part of the system. Perhaps you are never going to go that far with model railways and that's your perogative. If you can't see a signal from your driving position then how are you going to correctly drive your train?
Once you start dividing up your layout into signal blocks, you've divided your layout into electrical blocks. You need detection for each block so you need to put in feeds and detectors. An on/off switch in the feed is much simpler and cheaper than a decoder in a loco.

I've rejected DCC for the reason that the advantages do not outweigh the disadvantages as well as the cost factor. Had it not been for the cost factor I would long ago have converted fully to DCC but I would now be faced with working around those disadvantages by adding yet another layer of expensive technology.
Regards, Greg.P.
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Only if you don't have any friends. Once a month I have four people come an operate on my layout. We drive a train each from one end to the other, dooing what is necessary with respect to shunting, meeting other trains, etc, on the way. At the end of the journey we are then rostered onto another train.
When I am by myself I run one train at a time, often running a train to in intermediate station, then moving to the other end of the layout and driving another train towards the first. That's fine for me, as my operations and preferences are "driver centric".
This argument is nothing more that the "signalman centric" oprtation versus the "driver centric" operation. Some people prefer one, others prefer the other. Some layouts are designed to support one form of operation, some the other.
Neither one is the only possible solution, and without knowing what a layout owner's preferences are, nobody can make pronouncements that DCC is the best way forward, or the DCC will not allow operation on his (undefined) layout.
John Dennis
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John Dennis wrote:

Hey, how did you guess? ;-) I don't have friends on call anytime I feel like operating.

Sure, I quite agree with you at the basic level. Your form of operation would be quite suited to a New Zealand layout, but even though I live in NZ.
I'm more taken with European operation. The section of line I've chosen to model was from it's earliest years always a bottleneck, with improvements and technology constantly being added to increase it's capacity. Each train runs from signal to signal, with a train ahead and one behind and the signals maintaining safety. If I had sufficient friends to drive each train individually then there wouldn't be enough room in front of the layout for them all to stand! If this was modern image rather than 1930 the trains would be moving too fast for the operators to stay with their trains.

Now you've identified the moment when I blundered in! I commented on/disagreed with a recommendation to a beginner that he should go for DCC from the beginning.
Regards, Greg.P.

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"Gregory Procter" wrote

Now I was always under the impression that the driver of the loco/unit operated the train and obeyed the signals (TPWS, ATC &/or AWS allowing). In that respect DCC allows for prototypical operation.
John.
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In
Agreed. DCC allows you the most prototypical loco control currently available. You're not limited by artificial electrical blocks etc. SPAD and you're in deep do do. Just like the prototype.
-- Cheers Roger T.
Home of the Great Eastern Railway http://www.highspeedplus.com/~rogertra /
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"Roger T." wrote:

No-one is limited to artificial electrical blocks unless they are limited in other ways. The prototype operates it's trains by blocks and signals. If you want to be able to over-run signals with analogue control, just make your electrical blocks longer!
Regards, Greg.P.
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