Trains.com

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Newbie to DCC question

2829 views
15 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    January 2007
  • 327 posts
Posted by locoworks on Friday, August 13, 2010 2:41 PM

ahh, by 'again' you mean for the first time  Sign - Oops  i couldn't see it clearly on my little screen and didn't realise i could make it bigger..  that looks a bit OTT for what is required.

  • Member since
    September 2007
  • From: Charlotte, NC
  • 6,099 posts
Posted by Phoebe Vet on Friday, August 13, 2010 5:26 AM

Look at the diagram again.  He has two cabs connected to 8 segments with Atlas switches.

I don't believe that he intends to have both systems wired at once.  I believe that he left the plugs out of the diagram.  I base that belief on his statements.

Dave

Lackawanna Route of the Phoebe Snow

  • Member since
    January 2007
  • 327 posts
Posted by locoworks on Friday, August 13, 2010 2:56 AM

Phoebe Vet

I don't understand your point.

What I said is if he only uses two pins on the DCC plug, the bank of switches would all be just on or off.

I am not the one who suggested switches between DC & DCC systems, a system that I don't recommend.  I only commented on the wiring of the DCC plug.

i did also suggest the switch method, but the OP was on about a small double track loop with 2 controllers. i assumed 1 per loop, no mention was made of some elaborate layout with 'cab' control to be switching sections off or between controllers.  it sounded like just 2 pairs of feeds to the layout, one for each loop. putting the feeds through a 4 pole switch would never allow the DC and DCC to ever meet, but would only allow two feeds for DC ( 3 if you wired it common return ), i guess you could always split the circuits up into sections after the feeds with isolation sections for DC?

  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Thursday, August 12, 2010 9:29 PM

 Witht he diagram you put in, if you forget to disconnect one of the systems it will NOT work and will fry something. The top terminals across all the Selectors are wired together, so with both systems hooked up, there is a direct path between one side of the MRC dual pack and the DCC system.

 I'd go with the single 4 pin plug. Make the two middle ones the common side. Leftmost pin tot he top of the Selectors, rightmost pin to the bottom terminal of the Selectors. That way only one system could be pluggedin, and even if you somehow flipped the plug from the DCC system (most plugs are keys in some way - a hard drive molex connector from a PC would be great for this) it would just mean you'd have to set all the Selectors down instead of up.

 Do not go with any system that could allow both the DCC and DC to be connected at the same time. Relying on "I'm careful to make sure no locos bridge the gaps" is a sure-fire way to destroy the DCC system.

                                           --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

  • Member since
    September 2007
  • From: Charlotte, NC
  • 6,099 posts
Posted by Phoebe Vet on Thursday, August 12, 2010 7:46 PM

I don't understand your point.

What I said is if he only uses two pins on the DCC plug, the bank of switches would all be just on or off.

I am not the one who suggested switches between DC & DCC systems, a system that I don't recommend.  I only commented on the wiring of the DCC plug.

Dave

Lackawanna Route of the Phoebe Snow

  • Member since
    July 2008
  • 1,206 posts
Posted by mfm37 on Thursday, August 12, 2010 7:29 PM

 The other direction on each switch would then be "off", allowing him to be able to park unused locos on dead track until needed.

 

 

Unless one of those switches gets moved by mistake. The "air switch" method described is the safer choice.

  • Member since
    September 2007
  • From: Charlotte, NC
  • 6,099 posts
Posted by Phoebe Vet on Thursday, August 12, 2010 6:24 PM

He can do that if he wants to, but it's not necessary.  All he has to do is hook the DCC to poles one and two and throw all the switches to the same side, which turns on all the blocks.  The other direction on each switch would then be "off", allowing him to be able to park unused locos on dead track until needed.

Dave

Lackawanna Route of the Phoebe Snow

  • Member since
    January 2007
  • 327 posts
Posted by locoworks on Thursday, August 12, 2010 5:48 PM

have a 4 pole connector, two poles for each loop.  in DC mode you run one controller output to one pair of poles ( 1&2 ) and the other controller output to the other pair of poles (3&4 ).  in DCC mode you run one side of the output to poles 1 and 3 by daisychaining them, and the other side of the output to poles 2 and 4.   sorted.  you could even wire both systems through a 4PDT switch with the centre contacts going to the loops so you didn't have to bother plgging and unplugging between DC and DCC.

  • Member since
    September 2007
  • From: Charlotte, NC
  • 6,099 posts
Posted by Phoebe Vet on Thursday, August 12, 2010 4:59 PM

Zandoz

The plan is that DC & DCC should never be connected at the same time.  I had planned on separate plugs...a 2 wire for DCC, and a 4 wire for the double DC connections, but I see no reason I could not use a single 4 wire plug on the facia, but only use 2 of the wires for DCC.  The more fool proof the better.

Sounds like a good plan.

Dave

Lackawanna Route of the Phoebe Snow

  • Member since
    January 2005
  • From: Alexandria KY
  • 470 posts
Posted by Zandoz on Thursday, August 12, 2010 2:31 PM

The plan is that DC & DCC should never be connected at the same time.  I had planned on separate plugs...a 2 wire for DCC, and a 4 wire for the double DC connections, but I see no reason I could not use a single 4 wire plug on the facia, but only use 2 of the wires for DCC.  The more fool proof the better.

Reality...an interesting concept with no successful applications, that should always be accompanied by a "Do not try this at home" warning.

Hundreds of years from now, it will not matter what my bank account was, the sort of house I lived in, or the kind of car I drove...But the world may be different because I did something so bafflingly crazy that my ruins become a tourist attraction.

"Oooh...ahhhh...that's how this all starts...but then there's running...and screaming..."

  • Member since
    December 2004
  • From: Bedford, MA, USA
  • 21,483 posts
Posted by MisterBeasley on Thursday, August 12, 2010 2:30 PM

Truth:

CSX Robert
If I was going to do that I would only have one plug on the facia where I could plug in either the MRC 280 or the DCC system, but have no way of plugging both in at the same time.

Consequences:

You have a common wire directly between the DCC system and the MRC system.  If you ever turned them both on, you risk destroying a decoder or 3, or the DCC system itself.

It takes an iron man to play with a toy iron horse. 

  • Member since
    September 2007
  • From: Charlotte, NC
  • 6,099 posts
Posted by Phoebe Vet on Thursday, August 12, 2010 1:19 PM

CSX Robert
If I was going to do that I would only have one plug on the facia where I could plug in either the MRC 280 or the DCC system, but have no way of plugging both in at the same time.

I agree 100%

Dave

Lackawanna Route of the Phoebe Snow

  • Member since
    September 2007
  • From: Charlotte, NC
  • 6,099 posts
Posted by Phoebe Vet on Thursday, August 12, 2010 1:18 PM

My mistake.  I confused the Atlas Selector and the Atlas Connector.

The one you pictured will work as long as the systems are completely isolated.

Dave

Lackawanna Route of the Phoebe Snow

  • Member since
    February 2007
  • From: Christiana, TN
  • 2,134 posts
Posted by CSX Robert on Thursday, August 12, 2010 1:18 PM
If I was going to do that I would only have one plug on the facia where I could plug in either the MRC 280 or the DCC system, but have no way of plugging both in at the same time.
  • Member since
    September 2007
  • From: Charlotte, NC
  • 6,099 posts
Posted by Phoebe Vet on Thursday, August 12, 2010 1:12 PM

It will work if you are going to completely disconnect the DC or DCC system from the layout when it is not in use only if the selectors are double throw.  I don't believe that is the case with the Atlas Selectors you have shown.

DO NOT EVER HAVE BOTH SYSTEMS CONNECTED TO THE LAYOUT AT THE SAME TIME.  Not even if they are not powered.

Dave

Lackawanna Route of the Phoebe Snow

  • Member since
    January 2005
  • From: Alexandria KY
  • 470 posts
Newbie to DCC question
Posted by Zandoz on Thursday, August 12, 2010 12:38 PM

What I am planning is a small N scale Unitrack double track oval on a cutdown door.  I have an MRC 280 double powerpack, and in the future I plan on going to a Digitrax Zephyr DCC system.  I would like to be able to run the layout with either powering system, but never both connected at the same time.  To that end, my idea is to fasten 2 plugs to the layout facia...one 2 wire plug for the Zephyr, the other a 4 wire plug for the pair of DC feeds from the 280.  Both of those plugs would be connected to a pair of Atlas Selectors mounted on the facia...one slector for the outside loop and it's sidings, and the other for the inside loop and it's sidings.  The inside and outside loops will be insulate from each other at the crossovers, and all sidings will be insulated from the loop they connect to. Below is a drawing of what I have in mind.   The question is, am I on the right track?

 

66x36 wiring basics

Reality...an interesting concept with no successful applications, that should always be accompanied by a "Do not try this at home" warning.

Hundreds of years from now, it will not matter what my bank account was, the sort of house I lived in, or the kind of car I drove...But the world may be different because I did something so bafflingly crazy that my ruins become a tourist attraction.

"Oooh...ahhhh...that's how this all starts...but then there's running...and screaming..."

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Users Online

There are no community member online

Search the Community

ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT
Model Railroader Newsletter See all
Sign up for our FREE e-newsletter and get model railroad news in your inbox!