Brainstorm on going digital

The place for general discussions and requests for help on all matters relating to T gauge.
Post Reply
JoostV
Posts: 14
Joined: Sat Nov 16, 2013 10:23 am

Brainstorm on going digital

Post by JoostV »

Hi all,

Coming from the scale HO having DCC decoders in the locomotives I was wondering if I could somehow go digital on t-gauge.

As there's no space at all I was thinking following:

- Breakdown the track in blocks
- Create the digital bus (2 wires) which in H0 connects the controller to the track
- Put a DCC train decoder between the digital bus and the track (one decoder for each block)
- Limit output of the train decoders to 4.5v

This in theory would allow me to set the speed on each block independently by selecting the decoder address and turn the knob on the controller

Does above theory make any sense. Any obvious pitfall's?
Cheers,
Joost

JoostV
Posts: 14
Joined: Sat Nov 16, 2013 10:23 am

Re: Brainstorm on going digital

Post by JoostV »


User avatar
PolarExcess
Posts: 43
Joined: Fri Dec 06, 2013 3:09 am

Re: Brainstorm on going digital

Post by PolarExcess »

JoostV,

One idea might be to replace the decoder wires with the smallest possible gauge, perhaps kynar. Then install the decoder in the non motorized car directly behind the motorized locomotive and place a flexible diaphragm between the two cars to hide the wires. Refer to attached picture.

Others feel free to chime in and keep this brain storm going.
1.png
1.png (46.42 KiB) Viewed 20833 times

Slarge
Posts: 30
Joined: Thu Nov 14, 2013 8:22 am

Re: Brainstorm on going digital

Post by Slarge »

If you ran "trains" rather than locos (as per the larger scales) I see no problem with the above idea.
If you think about the concept of multiple units as used so far this makes perfect sense. Take the extended HST for example, There are 3 powered units, now I don't know much about DCC I will admit, I presume the decoder would need to be linked to each motor, so taking the above idea there would need to be a wired connection from one end of the train to the other, I would want some kind of micro pin connector to allow the train to be broken down and stored, this connection could also be used for "close coupling" (but what about freight wagons?).
The decoder could be in any of the 6 unpowered cars but the wires would need to pass the central motor at some point. (that leaves 5 empty cars, go crazy, add sound!).
Intresting concept, I look forward to more musings/thoughts.
Shame you can't yet "print" your own decoder, the science/tech isn't that far off the horizon (light years away in consumer terms though).

JoostV
Posts: 14
Joined: Sat Nov 16, 2013 10:23 am

Re: Brainstorm on going digital

Post by JoostV »

And how about my initial idea to put the decoder on the track, thus creating block's (like analog block system)?
Cheers,
Joost

User avatar
PolarExcess
Posts: 43
Joined: Fri Dec 06, 2013 3:09 am

Re: Brainstorm on going digital

Post by PolarExcess »

Slarge & JoostV,

I have some addt'l thoughts. More later, probably this wkend.






Sent from my iPhone using Tapatalk

User avatar
nscaler69
Posts: 10
Joined: Wed Nov 20, 2013 2:12 am
Location: Adelaide, Australia

Re: Brainstorm on going digital

Post by nscaler69 »

JoostV wrote:And how about my initial idea to put the decoder on the track, thus creating block's (like analog block system)?
Cheers,
Joost
You mean something like using this; http://www.ontracks.co.uk/index.php?pag ... dID=165499 interestingly this Busch HOf stuff uses 3 volt power and locos has magnetic wheels.

User avatar
PolarExcess
Posts: 43
Joined: Fri Dec 06, 2013 3:09 am

Re: Brainstorm on going digital

Post by PolarExcess »

Correct, a decoder would have to be connected to each motor. Though, it is possible to connect a single decoder to 2 motors.

If you ran a T-Gauge steam locomotive, the decoder might fit in the trailing tender.

Slarge, you raise several valid concerns, such as the micro pin connector, etc. My first step would to attempt decoder implementation on the simplest possible scale, such as using only two cars, a motored locomotive and an hollow passenger car to store the decoder. If a proof of concept was achieved, then I'd tackle the multiple unit wiring issues. Sound would be icing on the cake.

One thing to keep in mind is that DCC operates on constant voltage and it is the decoder that instructs the motor on how fast to turn, based upon your command. Therefore transition to a DCC track prevents simultaneous operation of DC (conventional) locomotives, unless they run at full speed.

Input track voltage might be another obstacle. Does the track transformer have enough current to power the decoder? Does the decoder accept AC/DC current or both?

I'm interested in reading additional input on this interesting topic.

Slarge wrote:If you ran "trains" rather than locos (as per the larger scales) I see no problem with the above idea.
If you think about the concept of multiple units as used so far this makes perfect sense. Take the extended HST for example, There are 3 powered units, now I don't know much about DCC I will admit, I presume the decoder would need to be linked to each motor, so taking the above idea there would need to be a wired connection from one end of the train to the other, I would want some kind of micro pin connector to allow the train to be broken down and stored, this connection could also be used for "close coupling" (but what about freight wagons?).
The decoder could be in any of the 6 unpowered cars but the wires would need to pass the central motor at some point. (that leaves 5 empty cars, go crazy, add sound!).
Intresting concept, I look forward to more musings/thoughts.
Shame you can't yet "print" your own decoder, the science/tech isn't that far off the horizon (light years away in consumer terms though).

User avatar
PolarExcess
Posts: 43
Joined: Fri Dec 06, 2013 3:09 am

Re: Brainstorm on going digital

Post by PolarExcess »

With this block method, could you run multiple independent units on the same track?

What would this block method offer over tradition T-Gauge transformer control?

I like the brainstorming. Thanks for starting it.
JoostV wrote:Hi all,

Coming from the scale HO having DCC decoders in the locomotives I was wondering if I could somehow go digital on t-gauge.

As there's no space at all I was thinking following:

- Breakdown the track in blocks
- Create the digital bus (2 wires) which in H0 connects the controller to the track
- Put a DCC train decoder between the digital bus and the track (one decoder for each block)
- Limit output of the train decoders to 4.5v

This in theory would allow me to set the speed on each block independently by selecting the decoder address and turn the knob on the controller

Does above theory make any sense. Any obvious pitfall's?
Cheers,
Joost

User avatar
dkightley
Posts: 1272
Joined: Wed Nov 13, 2013 9:43 pm
Location: Nottingham, UK

Re: Brainstorm on going digital

Post by dkightley »

With this block method, could you run multiple independent units on the same track?
No.
What would this block method offer over tradition T-Gauge transformer control?
In train control terms it would depend on the size of the layout. With only two or three "blocks", it would be cheaper to use one of the existing PWM controllers for each section of track....but once you get above a certain number of blocks, the cost of a single digital unit and a number of decoders will be less.

One basic obstacle to bear in mind, though...is what happens when a powered unit crosses the join between one block and the next? With one axle connected to block A and the rest connected to block B, there would be a direct short between decoder outputs through the internal power connection in the unit. Would this cause havoc to the decoder circuitry? And what about where the second block is set to run in the opposite direction? The least likely thing would be a train oscillating furiously back and forth over the gap!

Robins Run has two separate loops powered by separate controllers. There are two cross-over sections, each of which can be connected to either loop....so accidental shorting of the controllers is reduced to a low risk....but not prevented. Where you deliberately run from one block to the next block under power is a different thing!!

And I do like the idea of locating the decoder in a non-powered car. And the bogies on the non-powered cars could also be converted to pick up power....increasing the power pickup reliability!
Doug Kightley
Webmaster here and volunteer at the National Tramway Museum http://www.tramway.co.uk

User avatar
PolarExcess
Posts: 43
Joined: Fri Dec 06, 2013 3:09 am

Re: Brainstorm on going digital

Post by PolarExcess »

I too am a fan of the decoder in the trailing car(s). Rationale: it's risky, cutting edge AND no one has done it before, or in the very least posted a youtube video of it. I run O Scale (3 Rail) locos via DCC & DCS and love the results.

Still waiting on my T-Gauge starter set to ship from tgauge.com to the USA. Might be 2014 before I get them; therefore I patiently wait.


Sent from my rotary phone.

JoostV
Posts: 14
Joined: Sat Nov 16, 2013 10:23 am

Re: Brainstorm on going digital

Post by JoostV »

Hi all,

To be honest, it's not about cost, but about the challenge- being able to control the layout from my computer. On my old H0 track I had custom software running on a windows PC and access to it from my tablet (remote desktop). Yes it had a custom UI to allow finger movement to select loco's, set switches etc. Would be interesting to go there again :)

Sure.. a long way to go.. Still have issues coupling my HST. Everything is soooo small :)

Btw I also started a topic on the dutch beneluxspoor forum as there's a lot of digital knowledge there as well... Will share the results :)

Slarge
Posts: 30
Joined: Thu Nov 14, 2013 8:22 am

Re: Brainstorm on going digital

Post by Slarge »

JoostV
So in very simplistic terms am I correct in thinking you are looking to use your computer to control the train by way of a DCC decoder... In essence the decoder is translating the commands from the computer and the track is acting as the wired connection to the motor?
Thus creating a digital controller rather than traditional DCC?
If so I can see how a single loop would work, but for blocks my concerns would be the same as dkightley's.

mattd10
Posts: 206
Joined: Wed Nov 13, 2013 10:12 pm
Location: West Sussex, UK
Contact:

Re: Brainstorm on going digital

Post by mattd10 »

Im finding all this fascinating reading. Ive never done dcc in the larger scales but I think it'd be great for T!

I remember I posted a link to the smallest decoder I could find on the old forum....it was just small enough to squeeze into a trailing coach if I remember rightly! I'll try and find it again if I can.

Im sure theres a video on youtube of a 103 unit with a decoder fitted externally as a proof of concept...I'll see if I can find that too!

Sent from mobile device

JoostV
Posts: 14
Joined: Sat Nov 16, 2013 10:23 am

Re: Brainstorm on going digital

Post by JoostV »

@Slarge

Exactly :) :)

Cheers,
Joost

mattd10
Posts: 206
Joined: Wed Nov 13, 2013 10:12 pm
Location: West Sussex, UK
Contact:

Re: Brainstorm on going digital

Post by mattd10 »

http://www.youtube.com/watch?v=9q4OmmoO85I

Video

http://www.digitrains.co.uk/ecommerce/l ... coder.aspx
http://www.digitrains.co.uk/ecommerce/l ... coder.aspx

at 6.9x6.1x1.7mm this thing is TINY! :shock: But you'd still struggle to squeeze one in an empty coach...even on a slant! Definitely do-able though!

Post Reply