DCC starting out - I'm not a techy but so far its been worth it!

[Ron Ron Ron]

2 hours ago, Pete the Elaner said:

.....The video's presenter was just trying to justify his statement that the higher voltage of DCC copes with rail resistance better than low voltage for DC, especially for slow running.

 

He could have done that simply and fairly quickly, in plain language.

 

I bet he's an engineer ............... (Not a Scooby about how the end user will use or interact with the finished product).

 

 

 

 

...

[rockershovel]

2 hours ago, Ron Ron Ron said:

 

He could have done that simply and fairly quickly, in plain language.

 

I bet he's an engineer ............... (Not a Scooby about how the end user will use or interact with the finished product).

 

 

 

 

...

 

Well, I’m an engineer, and that’s a classic example of the sort of thing I mentioned before. It’s all technically correct, I don’t doubt, but it could have conveyed it’s essential points in less than half the length, and given all the detail necessary for its target audience in 8-10 minutes. 

 

Engineers do this, all the time. It’s the difference between a Procedure and a Method Statement. 

 

[boxbrownie]

16 hours ago, Pete the Elaner said:

It echos how I feel with this forum sometimes.

You can often make a simple statement & can almost feel the trolls hovering over their keyboards, waiting to distort something out of context...

At that point I just bail......life is too short

[grriff]

I would sum up the pros and cons of DC and DCC as follows:

DC pros

For a layout with only one loco on the track - cheap and simple.

DC cons

For a layout with more than one loco on the track - requires ability to isolate locos.

For a layout running more than one loco - requires more complex wiring and multiple controllers.

 

DCC pros

Individual control of locos, so no complex wiring.

Many controllable functions available, such as lights and sound.

Improved slow running, compared to a DC resistance controller.

Can operate accessories using DCC.

 

DCC cons

Comparatively expensive. DCC decoders, for each loco, typically cost around £20 each. Controllers may be several £100. Sound can add £100 to the cost of a loco.

Some technical 'involvement' required. At a minimum, a new loco's address will need to be changed from the default value of 3. To get the best out of DCC more technical involvement is required.

You will need to buy and fit DCC decoders to your existing DC locos. This can be difficult - may require soldering and space for the decoder might be a problem. Older locos may not be convertible. Some new locos may not have DCC decoders fitted. Check that the retailer will do this for you, if required.

Operating accessories using DCC requires more technical knowledge, expense and wiring.

 

The big question revolves round the technical involvement required by DCC. If you have trouble setting up a video recorder or using a smartphone, DCC is unlikely to be your 'cup-of-tea'. My advice would be to visit a shop specialising in DCC and ask them to demonstrate how they would change the address of a loco for each system they sell. Could you do this? Ask to look at a copy of each manual. Does it look as though you could understand it? Will the shop provide telephone assistance if you get stuck? How expensive is the system they are demonstrating? It may not be the 'basic' system they will sell to you.

 

Incidentally, does the information given in the video about DC voltages apply to modern DC controllers? I thought they provided pulsed DC (PWM - pulsed width modulation) in the same way that DCC does. (PWM provides a constant 12v and controls speed by sending pulses, 'square waves',  to the loco. The longer the pulse the higher the speed). The difference being that DCC also uses PWM to send information to the DCC decoder in the locomotive. Certainly DCC should be better for slow running than an old DC resistance controller but I've no experience with a modern DC PWM controller.

 

[RAF96]

When at the DCC controller decision stage in the shop, be aware that a simple DCC controller may suffice for now but once you get your teeth into DCC you may want something more capable. You may be surprised at how short that teething interval is.

[rockershovel]

You might try reading this     https://dccwiki.com/DCC_Power     which allows you to skip the “how and why it works” and go straight to “how does it operate” - which isn’t the same thing at all, and is probably what the OP is actually asking. 

 

I freely admit that electrical engineering baffles me. I’ve never understood, for example, why an AC motor doesn’t simply seize up from receiving current in both directions, or how it goes in any specific direction. However I long ago concluded that provided I knew what to expect when I operated the lever, and what it’s operating parameters were, that was of no importance. 

 

This is why why I gave up on the MERG group at the club, they were telling me nothing I could use. I also noticed that when the NCE controller was sorted out, a whole constituency of people took an interest, but were only really interested in making the loco run, and operating the whistle. Once they could do THAT, the rest of the subject completely passed them by, especially the ones most interested in operating locos on existing layouts. As one of them pointed out, DCC accessories are of no interest if you already have rod, or cable operated points (or in one case, a stick with a rubber on the end, with which to flick the levers across... ). 

 

 

[Crosland]

4 hours ago, grriff said:

DCC cons

 Sound can add £100 to the cost of a loco.

 

Sound is nice, but not neccessary, so it's unfair to list it as a con for DCC, unless you know of a much cheaper sound option for DC to compare it against.

 

It's important to compare like-for-like.

[Crosland]

2 hours ago, rockershovel said:

You might try reading this     https://dccwiki.com/DCC_Power     which allows you to skip the “how and why it works” and go straight to “how does it operate” - which isn’t the same thing at all, and is probably what the OP is actually asking. 

 

Sorry, but if you want simplicity. most peoples eyes will glaze over by the end of the second paragraph

 

As an engineer who designs DCC systems, it's actually a very muddled description of DCC, whether looking for simplicity or technical detail. IMHO, DCC Wiki has never been the place to go for this kind of information.

[Ron Ron Ron]

4 hours ago, grriff said:

DCC cons

.....Sound can add £100 to the cost of a loco.

 

32 minutes ago, Crosland said:

 

Sound is nice, but not neccessary, so it's unfair to list it as a con for DCC, unless you know of a much cheaper sound option for DC to compare it against.

 

It's important to compare like-for-like.

 

Agreeing with Andrew here.

It can't be a "Con" if it isn't directly comparable with non-sound DC.

 

Anyway, sound can be added from around £18 - £25 extra, up to over £100 extra.

It depends on what sound decoders you are buying.

Hornby TTS decoders can be had for as little as £34

 

 

.

[rockershovel]

36 minutes ago, Crosland said:

 

Sorry, but if you want simplicity. most peoples eyes will glaze over by the end of the second paragraph

 

As an engineer who designs DCC systems, it's actually a very muddled description of DCC, whether looking for simplicity or technical detail. IMHO, DCC Wiki has never been the place to go for this kind of information.

 

.... well, fair do’s. I certainly couldn’t understand it, but I’ve never understood electrical engineering or design. 

 

I was recommended the Gaugemaster Prodigy by Digitrains, although in the event I discovered (once the unit at the club test track was revived) that I actually preferred the NCE unit, mostly because the chassis and keypad appear to be the same, or closely related to the survey instruments which I know very well. It’s much more ergonomic to hold than the Gaugemaster. 

 

I was surprised to learn (from Digitrains) that Lionel had a two-channel version of DCC as early as the 1940s. I did vaguely recall that Hornby had a system of the sort in about 1980. 

 

 

 

 

 

[Ron Ron Ron]

3 minutes ago, rockershovel said:

.....I was surprised to learn (from Digitrains) that Lionel had a two-channel version of DCC as early as the 1940s. I did vaguely recall that Hornby had a system of the sort in about 1980. 

 

The early Lionel systems were not Digital at all, so not a version of DCC.

It comes under the general description of "Command Control", of which DCC (Digital Command Control) is the latter day, long standing, dominant and standardised manifestation.

 

There must have been nearly 2 dozen different attempts at Command Control systems, from around that late 40's, early 50's era (particularly in the 70's and 80's) ... until DCC first arrived on the scene in the early 1990's.

The DCC Wiki site lists most, if not all of them, on a history page.

 

Hornby's Zero 1 system (introduced around 1980 'ish)  was a relative late comer, but is supposed to have been the first truly all-digital Command Control system. Albeit very crude by later standards.

 

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[Ron Ron Ron]

5 hours ago, grriff said:

.....Incidentally, does the information given in the video about DC voltages apply to modern DC controllers? I thought they provided pulsed DC (PWM - pulsed width modulation) in the same way that DCC does. (PWM provides a constant 12v and controls speed by sending pulses, 'square waves',  to the loco. The longer the pulse the higher the speed). The difference being that DCC also uses PWM to send information to the DCC decoder in the locomotive. Certainly DCC should be better for slow running than an old DC resistance controller but I've no experience with a modern DC PWM controller.

 

 

I'm no techie grriff, but I don't think it works that way.

I'm sure Andrew, Nigel or one of our other esteemed DCC technical experts will correct me if I'm wrong.

 

My understanding is that the DCC signal provides a constant Voltage and the encoded DCC Command pulses are just data that contain speed commands (along with other commands), as a digital coded instruction to the decoder (i.e. the "DCC Controller"), telling it what speed control it should apply from its own motor outputs.

The "controller" function of the decoder uses these instructions to control the switching of the motor voltage, to generate the pulsed DC from the motor drive element of the decoder,   i.e. the pulsed DC supplied to the motor is sent from the decoder itself, it don't come from the DCC system.

In other words, the DCC system sends out the Commands (instructions) and the decoder controls the loco.

 

 

p.s. There's no need to know how it works. It just does.

.

[rockershovel]

.... which leads to a whole ‘nother issue, controlling trains (or any other function of your choice) from tablets or smartphones. There must be some crucial difference between functions controlled from a single, unified power supply and controller, and functions controlled by a third-Party controller, completely unconnected to the power supply? 

 

Clarke’s Third Law applies, I think...

 

 

 

[Pete the Elaner]

12 minutes ago, rockershovel said:

.... which leads to a whole ‘nother issue, controlling trains (or any other function of your choice) from tablets or smartphones. There must be some crucial difference between functions controlled from a single, unified power supply and controller, and functions controlled by a third-Party controller, completely unconnected to the power supply? 

 

Clarke’s Third Law applies, I think...

 

 

 

A DCC controller can be broken down into 3 discrete components. Some combine 2 of these into 1 device, others combine all 3 into the same device.

 

Throttle - The operator's device

Command station - 1 & only 1 of these per system. Takes the input from the throttle(s) & sends commands to the layout.

Booster - takes the low voltage signal from the command station & sends it at 'layout level' to the layout.

 

The smartphone is just another throttle.

So the only difference between a throttle on a smartphone & a dedicated one is the way features/functions are displayed & accessed.

Some may prefer the feel of a smartphone app. I prefer my 'proper' throttle to any smartphone app I have tried but, being software based, I could find a free one tomorrow which changes my mind.

[Crosland]

55 minutes ago, Ron Ron Ron said:

My understanding is that the DCC signal provides a constant Voltage and the encoded DCC Command pulses are just data that contain speed commands (along with other commands), as a digital coded instruction to the decoder (i.e. the "DCC Controller"), telling it what speed control it should apply from its own motor outputs.

The "controller" function of the decoder uses these instructions to control the switching of the motor voltage, to generate the pulsed DC from the motor drive element of the decoder,   i.e. the pulsed DC supplied to the motor is sent from the decoder itself, it don't come from the DCC system.

In other words, the DCC system sends out the Commands (instructions) and the decoder controls the loco.

 

Yes, that's it. It's like having a top-spec, adjustable (inertia, braking, feedback control, ...), DC PWM controller in every loco.

[Ron Ron Ron]

6 minutes ago, Crosland said:

Yes, that's it. It's like having a top-spec, adjustable (inertia, braking, feedback control, ...), DC PWM controller in every loco.

 

Indeed.

The very essence of DCC, compared with DC, is that the "controller" has been moved from the track side and placed inside the loco itself.

Every loco has its own controller onboard (as per the prototype- steam, electric or diesel) and we control the controller, in other words drive the trains, by remote control using the DCC system.

 

 

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[rockershovel]

26 minutes ago, Pete the Elaner said:

A DCC controller can be broken down into 3 discrete components. Some combine 2 of these into 1 device, others combine all 3 into the same device.

 

Throttle - The operator's device

Command station - 1 & only 1 of these per system. Takes the input from the throttle(s) & sends commands to the layout.

Booster - takes the low voltage signal from the command station & sends it at 'layout level' to the layout.

 

The smartphone is just another throttle.

So the only difference between a throttle on a smartphone & a dedicated one is the way features/functions are displayed & accessed.

Some may prefer the feel of a smartphone app. I prefer my 'proper' throttle to any smartphone app I have tried but, being software based, I could find a free one tomorrow which changes my mind.

 

But MORE mutually incompatible hardware, no? 

 

The most useful thing I could have learned when I first became involved with DCC, was that none of this stuff was interconnected, because the plugs and wiring aren’t interchangeable. 

[Ron Ron Ron]

37 minutes ago, rockershovel said:

 

But MORE mutually incompatible hardware, no? 

 

The most useful thing I could have learned when I first became involved with DCC, was that none of this stuff was interconnected, because the plugs and wiring aren’t interchangeable. 

 

The difference with using a smart device (phone or tablet) is that at the receiving end, there's some form of interface with the DCC system, either within or attached to the DCC system, or in some computer software that's connected to and works with the DCC system.

That's where the compatibility is created.

 

A crude simplistic analogy....

You are standing on one side of a road and a Chinese person is standing on the other side of the road.

You want to talk to the Chinese person and you call across, but he doesn't speak English and doesn't understand. - incompatibility.

Now an interpreter, who speaks both languages, joins the Chinese person.

You can now speak to the Chinese person with the interpreter providing an interface and the Chinese person understands.

The Chinese person can also speak to you (via the interpreter) and you can fully understand what he's saying.

 

DCC throttles and other input devices are limited to use with their own manufacturers systems, or with compatible brands.

Any throttle would work with any make, if there was a suitable interface able to translate.

However, it's generally not practical and not commercially attractive to provide these interfaces just so you go and buy a rival company's accessories.

WiFi and computer technologies provide a way around this and a means to use third party devices, like smartphones and tablets, as throttles.

 

 

 

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Edited November 16, 2019 by Ron Ron Ron

[Ron Ron Ron]

1 hour ago, Pete the Elaner said:

.....Some may prefer the feel of a smartphone app. I prefer my 'proper' throttle to any smartphone app I have tried but, being software based, I could find a free one tomorrow which changes my mind.

 

I have both the "'proper' throttle" and the smartphone app....on the same handset !

 

  

Edited November 16, 2019 by Ron Ron Ron

[boxbrownie]

My DCC throttle/controller/booster ad infinitum is all one unit, just as simple as the old DC controller ie H&M Duette......I do not want a lot of separate components with trailing wires everywhere.

 

It can be done differently of course, but it’s not what I wanted. Same as control over the points all in the same unit and no extra wires trailing under or over the layout, it’s me.....I just like a simple (if expensive ) life.

[rockershovel]

.... so, to continue the (somewhat laboured) analogy of the Chinese DCC operator....

 

....looking at my existing Gaugemaster unit, with everything operated from the one handset, the person I wish to communicate with ISN’T Chinese, but English and is already standing next to me. This is just as well, because neither of us have the ability to summon a Chinese interpreter in any case. .. is that it? 

 

 

I showed the NEC cab controller to an electrical engineer who knows nothing of DCC, but does know about manufacturing robots. He immediately identified it as a proprietary chassis and keypad, with numerous variants. This didn’t surprise me, it’s obvious from its more “developed” appearance compared to the Gaugemaster unit, which he was unable to identify. 

 

 

Survey equipment has ling since gone down the path of remote operation, by servo, controlled by remote keypads and handsets linked by Bluetooth, wireless or IR. There was an attempt by suppliers to restrict inter-compatibility for commercial reasons, and retaining control of functionality but the over-arching presence of Microsoft, USB cables and third-Party software developers meant that by now, although keypads are instrument-specific, data transfer and processing is pretty much universally interchangeable. 

 

This doesn't mean that all programmes have the same features, of course. Depending on the task, you might go to one specific supplier; you might also have QA reasons to standardise, to comply with manufacturers recommendations. 

 

 

 

[WIMorrison]

Either I have lost the plot or this thread has started to go way of course, my view is that it is the latter.,

[Ron Ron Ron]

5 minutes ago, WIMorrison said:

Either I have lost the plot or this thread has started to go way of course, my view is that it is the latter.,

Agreed.

The OP asked a simple question and later a few supplementary questions.

Without re-reading the whole thread, I think those questions were mostly answered.

Now it’s become a rambling thread, with no particular point, which shouldn’t really be in this section at all.

 

 

[boxbrownie]

Get it locked then........

[halsey]

On 11/11/2019 at 12:54, boxbrownie said:

I'd be interested to know just how firm the foam is, I'd like to cover my baseboard all over with a layer as well for exactly the same reason, wiring for lighting etc......my board has to be sectional and I am worried the rail at the joints will not be firm enough on the foam to be in total alignment, I wonder if cork might be better in my situation?

Sorry missed this question - the (10mm) I bought foam is very firm unless you lean elbows on it - I have covered with 2mm cork and that makes it feel less vulnerable