Idiots guide to DCC.......

[dunnyrail]

For what it is worth @Fitz Orchard I also think you did a good job, there clearly is a view that @Software Tools has and is known for upsetting views elsewhere. I tend to ignore such comments these days unless I can see that they are entirely wrong or too elitist. Penanticism can be rather a nasty affliction, guilty of it myself at times but I keep it to things that I know are clearly off the wall.

 

[stevedenver]

Fwiw, Fritz, your post was exactly how i too understand things.
And, helpful.

Folks criticize but forget to add anything truly useful. Definitions are not illustrative, speaking for myself.

 

[Software Tools]

there clearly is a view that Software Tools has and is known for upsetting views elsewhere

The simple fact is that electricity is potentially deadly, and may kill you in flash if you get it wrong. Propagating explanations about electricity which are misleading remains extremely naive, no matter what the intent was.

As previously stated it is not hard to find simple, and correct, explanations regarding the nature of electricity.

 

[dunnyrail]

The simple fact is that electricity is potentially deadly, and may kill you in flash if you get it wrong. Propagating explanations about electricity which are misleading remains extremely naive, no matter what the intent was.

As previously stated it is not hard to find simple, and correct, explanations regarding the nature of electricity.

Agree in part, but we are talking low voltage power to track and accesories, even the most electrically inept modeller should understand the difference between the mains from the house and the low power passing to the train set. Perhaps this could be mentioned in the guide to assist/save any possible doubt?

 

[stevedenver]

Most useful, indeed.

 

[Paul M]

Agree in part, but we are talking low voltage power to track and accesories, even the most electrically inept modeller should understand the difference between the mains from the house and the low power passing to the train set. Perhaps this could be mentioned in the guide to assist/save any possible doubt?

Unfortunately the instruction about "disconnecting from the mains" is often the one ignored.

 

[dunnyrail]

Unfortunately the instruction about "disconnecting from the mains" is often the one ignored.

Well yes I guess there is no accounting for idiots.

 

[Paul M]

Well yes I guess there is no accounting for idiots.

Until they pay their account in full, obviously

 

[Mobi]

While I personally don't use DCC I found this thread interesting to understand the concept.

I got following image from internet which explains the pulse wave of DCC.


The pulse waves are fed thru tracks and go to every loco. But the address ensures only the intended recipient loco acts on this message.

DCC is similar to AC but AC follows sine wave (50 or 60 times per second) where as DCC creates square waves (thousands of times per second). While DCC is AC like it is actually DC because loco motors are DC motors.

As a side point, locomotives use brushed DC (BDC) motors. Technically brushless DC motors (BLDC) are superior but DCC can't handle BLDC due to some complex electronic signal management issues (as I understood from ChatGPT).

Batteries or analog DC can handle BLDC via simple electronic speed controller (ESC). Usually for same size, BLDC motors are more efficient and delivers more torque compared to BDC, thus it will run longer with same battery compared to BDC motor.

Has anyone here used BLDC in G scale locomotives?

 

[PhilP]

While DCC is AC like it is actually DC because loco motors are DC motors.

NO!

The DCC waveform is alternating current, end-of.

As the DCC waveform / track-voltage enters the decoder, it 'sniffs' off the DCC signals, and then passes track-voltage through a bridge-rectifier, voltage regulation and conditioning to give DC voltages for powering the chips on the decoder, and to be fed to the speed controller circuitry on the decoder.
Nine times out of ten ALL the output voltages to the motor(s), lights, etc. are PWM DC.
The 'sniffed' signal is used to decide if incoming DCC data is addressed to this particular decoder. If it is, the information is used to instruct the decoder to 'do something'. If not, it is ignored.

PhilP.

 

[Software Tools]

Technically brushless DC motors (BLDC) are superior but DCC can't handle BLDC due to some complex electronic signal management issues (as I understood from ChatGPT).

Again... undirected AI tools are not a reliable source of information.

 

[Paul M]

Again... undirected AI tools are not a reliable source of information.

True, look at it as if you're learning the true facts behind the bike sheds at school.

 

[dunnyrail]

NO!

The DCC waveform is alternating current, end-of.

As the DCC waveform / track-voltage enters the decoder, it 'sniffs' off the DCC signals, and then passes track-voltage through a bridge-rectifier, voltage regulation and conditioning to give DC voltages for powering the chips on the decoder, and to be fed to the speed controller circuitry on the decoder.
Nine times out of ten ALL the output voltages to the motor(s), lights, etc. are PWM DC.
The 'sniffed' signal is used to decide if incoming DCC data is addressed to this particular decoder. If it is, the information is used to instruct the decoder to 'do something'. If not, it is ignored.

PhilP.

Aha a quick question to someone who may know, would Dc power from DCC chip be OK for a Portescap motor?

 

[PhilP]

Aha a quick question to someone who may know, would Dc power from DCC chip be OK for a Portescap motor?

You will most likely be fine..

Older Portescap motors tend to get hot if run from PWM. - Reducing the PWM frequency can help, but then you can hear it.

There are 1000's of older O gauge, and 100's of older gauge 1 models with these motors and running under DCC.

You best bet is to try running with the body off, and checking the motor every few minutes..
If it is slightly warm (it is using energy, and doing work) it should be fine. - If it is appreciably hot, then you need to look at a different solution.

PhilP.

 

[Hal Farsed]

Fascinating. As I am an idiot when it comes to DCC, I feel I am qualified to ask the following: If say, I was to purchase an MTS fitted loco, would it be a simple if expensive matter to buy a Tx4.2 and FRx24-5A from Fosworks, remove track pick ups and install batteries on a dead rail layout? If this is cobblers, please read second sentence again. .
Sorry chaps just realised I brought this up a while ago and it was comprehensively covered. Time for a lie down I think!

 

[PhilP]

It's complicated....

The Fosworks system is really geared up to talk to the Fosworks supplied ESU decoder..

Assuming it uses DCC address 3 between the PWM output of the receiver/ESC, then basic functions should probably work.
Anything fancy, then no, as the decoders are from different manufacturers.

@andyspencer Anything to add?

PhilP.

 

[dunnyrail]

It's complicated....

The Fosworks system is really geared up to talk to the Fosworks supplied ESU decoder..

Assuming it uses DCC address 3 between the PWM output of the receiver/ESC, then basic functions should probably work.
Anything fancy, then no, as the decoders are from different manufacturers.

@andyspencer Anything to add?

PhilP.

Erm I have coupled the Fosworks DCC to a Massoth decoder, my expectation and understanding is that Fosworks will couple to most G scale decoders. Only caveat is that as supplied the CV1 needs to be at default 3. However Steve can change this on supply but this is only really necessary if you need to have your loco to a revised CV1. Tis much easier to change CV1 on your decoder rather than having a revised Fosworks DCC interface CV1 revised.

 

[Rhinochugger]

I don't think there i such a thing as an idiot's guide to DCC ............................. as an idiot, I have decided the sensible thing was to stay away from DCC.

I can understand DC, where you have two cables, a black one and a red one ............................... or, in certain instances, two green ones*

* Apologies for an 'in joke'.

 

[maxi-model]

t's complicated....

The Fosworks system is really geared up to talk to the Fosworks supplied ESU decoder..

Assuming it uses DCC address 3 between the PWM output of the receiver/ESC, then basic functions should probably work.
Anything fancy, then no, as the decoders are from different manufacturers.

@andyspencer Anything to add?

PhilP.

I have 3 x ESU DCC (V3.5 & V4) sound decoder/ESC fitted, battery powered locos, using the Fosworks Omni Tx-4.3 transmitter and FRx24-5a recievers. I'm in need of 3 more to be done (this time using ESU V5 max cards). These conversions were done by a now former Fosworks agent. All 3 are installed in Bachmann Fn3 locos. The irst 2, respectively V3.5 & V4, are a 2 Truck Shay and a Heisler, both are pre' "DCC Ready" products, but the Shay had a factory DCC wiring diagram provided. Don't ask how it was done, I do not wish to destroy the magic contained therein The latter is a 2-6-6-2 Mallet, which has Bachmann's later standardized DCC Plug n' Play (PnP) adapter board, that is a much "simpler" installation proposition. See picture below. I hope these extra V5 units can be supplied as ready programmed and wired assemblies to install done by Fosworks. That is if I send them the PnP cards the locos are supplied with. I went this route, when converting some of my roster to battery/rc operation, as the ESU cards offered a prototypical loco specific sound library. That, while there is higher cost compared to a simpler DC/MyLocoSound alternative, is part offset as the ESU card provides the ESC function in its price. Ok, it's still a hike.

Quick break down of the Mallet install. First all the bits, speaker, batteries, wiring harness, Tx & Rx and the ESU card to go in. Everything stripped down, had to cut down the main PCB board mounting height to do this installation. ESU V4 and its carrier card sits atop and wired to the Bachmann PnP (supplied as ready wired to attach DCC card of your choice) adapter board which in turn is plugged into the standard main PCB in the loco. Everything packs away and stows "under the hood", batteries and Rx in the ssddle tanks in this installation. Pictures of completed Shay, Heisler too.
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