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Control Staging Track Power with DCC?

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Control Staging Track Power with DCC?
Posted by Goldstms on Wednesday, August 30, 2017 5:35 PM

Does anybody know of a way to turn staging tracks on and off using DCC? Basically looking to use some sort of accessory decoder to actually cut the power to individual tracks. I know this can be done with SPST switches but I'm hoping to keep everything electronic. Thanks!

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Posted by rrinker on Thursday, August 31, 2017 5:10 PM

 Pretty easy DIY. The Traintek Aux-Box appears to be discontinued, and was ridiculously expensive.

http://www.trainelectronics.com/DCC_Arduino/Decoder_board/relays.htm

                                 --Randy

 

 


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Posted by Stevert on Thursday, August 31, 2017 10:25 PM

If you're using Digitrax/LocoNet, you can selectively turn the sections of a PM42 off and on with JMRI, WinLok, etc.

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Posted by carl425 on Friday, September 01, 2017 12:56 PM

Like Randy said, it's an easy DIY.  You can use a stationary decoder to drive a relay board like this to control track power in your staging yard.

https://www.amazon.com/gp/product/B00KTELP3I/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

Just tell the DCC system that the relay is a turnout.  When you set up your routes for staging, include the relay as one of the turnouts in the route.

These relays are also SPDT so if your interested you can supply a trickle current when a track is "off" to allow your block detectors to still work.

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Posted by BigDaddy on Friday, September 01, 2017 6:13 PM

carl425
Just tell the DCC system that the relay is a turnout.

To youse guys, the Electrical Illuminati, easy and just tell the DCC system this or that is easy for you to say.  The rest of us, the unclean and perhaps deplorable, we are clueless how to tell the system that a relay is a turnout. 

This comment, while true, is not meant to offend anyone's religion or superior knowledge of electronics. 

 

Henry

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By the Chesapeake Bay

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Posted by riogrande5761 on Friday, September 01, 2017 6:52 PM

Or just simply turn your staging into blocks and turn the power off to tracks individually - cheap and low tech!

Rio Grande.  The Action Road

Contrarian's contrarian
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Posted by rrinker on Friday, September 01, 2017 7:23 PM

Yeah but the OP didn;t want to do that.

As for telling the system the relay is a turnout, well, you don't really do anything of the sort, a relay already is a turnout, well, a switch machine. If you use the Atlas Snap Relay - it's a switch machine that changes contacts instead of moves the points. It gets wired to a DCC accesory controller exactly the same as you hook up a switch machine. Too many people get bogged down witht he idea that something different MUST be difficult when in fact it is the same thing they've been doing all along.

 If you can wire a toggle switch to turn off the track power, you can wire an Atlas Snap Relay to do it. There's really nothing further to understand or some new concept - you already have the knowledge if you can hook up a toggle switch. Just because the Snap Relay doesn't physically look much like a toggle switch doesn;t alter the same basic electrical hookup you already know, if you know how to wire a toggle switch.

 Something that LOOKS more complicate, like the Arduino design I linked - there are step by step instructions. Treat it like a kit. Not everyone who can build structure kits knows how to build a hoouse from the ground up, but they can still follow the instructions in the kit to build a model house.

 90% of model railroad electricty boils down to the basic cooncept that there must be a complete circuit from the source, to the locomotive, and back to the source. No short cuts (short circuits) and no breaks (switches - open circuit) or the power will not flow. The water in a hose analogy sort of breaks down here but a short circuit would be something like a big hole in the hose allowing the water to escape before it gets to the nozzle and a switch would be a valve, an open circuit like a cut wire would be akin to kinking the hose.

                              --Randy

 


Modeling the Reading Railroad in the 1950's

 

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

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Posted by carl425 on Friday, September 01, 2017 9:47 PM

rrinker
As for telling the system the relay is a turnout, well, you don't really do anything of the sort

Sure you do.  If you can control the relay like you control a turnout with the DCC throttle or a route table, you are able to do so because the DCC system thinks it's because the system thinks it's a turnout.

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Posted by Goldstms on Friday, September 01, 2017 9:55 PM

Thanks all. I like the idea of using the Amazon relay board that Carl linked to. To use that particular board I'd need a stationary decoder with 5VDC outputs correct? Any suggestions? I was looking at the CVP products stationary decoder but it has 12V outputs so I'd just need a different relay board I think. I'm considering going down the Arduino route as well but since I only need 8-10 total outputs I'd rather keep it simpler. 

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Posted by rrinker on Saturday, September 02, 2017 10:52 AM

 Yes, but that's the distinction - the SYSTEM thinks it's a turnout.

Wanna know another secret? When it comes to DCC signal controllers like a Digitrax SE8C, your SIGNALS are turnouts too!

                                  --Randy

 


Modeling the Reading Railroad in the 1950's

 

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Posted by carl425 on Saturday, September 02, 2017 11:05 AM

BigDaddy
the Electrical Illuminati

LOL - no way I'm part of this group.

I think maybe I overly simplified the issue and Randy maybe over complicated it - you certainly don't need to learn how to program an Arduino to make this work.

Here's an "official" way to do it, published by NCE.

https://ncedcc.zendesk.com/hc/en-us/article_attachments/200585165/Dual_relay.pdf

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Posted by richg1998 on Saturday, September 02, 2017 11:30 AM

I woulds use a decoder to control a relay. I have seen that to operate a smoke unit.

Function decoder. Or an unused decoder and use a light function. Hundred ohm, 1/2 watt resistor across the motor leads. Adjust CV's to keep from overheating the resistor.

Rich

N

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Posted by rrinker on Saturday, September 02, 2017 2:11 PM

 The only complication is the specs for the stationary decoder. Some are very specific and meant either for slow mootion low current motors like the Tooortoise - they keep the power on continuously, which is what you need for the relay, but can only output  limited amount of current. The high current types for solenoid motors only keep the power on for a fraction of a second, and won't work for regular relays (but are perfect for Atlas Snap Relays)

 You need the relay powered long enough for the power to move out of the staging track and onto the main.

 I submit the Arduino example not because it's complicated (it's not - and you do NOT have to learn how the programming works just to use it) but because it is by at least an order of magnitude cheaper than a commercial option. There once was a commercial device on the market called the Aux Box, which was prtty much exactly the same thing - a DCC controlled device to switch high power (via relays) (many amps) - instead of the typical low power (few milliamps) you can control with most decoders. It also cost somewhere around $149. To buy the parts to replicate that Arduino unit would cost no more than $10. It's like buying a car kit for $5 vs buying the RTR one for $40.

 It never hurts to learn something new. I'm always watching and learning new things, not just electronics.

                            --Randy

 


Modeling the Reading Railroad in the 1950's

 

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Posted by carl425 on Saturday, September 02, 2017 3:04 PM

rrinker
The only complication is the specs for the stationary decoder. Some are very specific and meant either for slow mootion low current motors like the Tooortoise - they keep the power on continuously, which is what you need for the relay, but can only output  limited amount of current.

The coils on the relay board I linked to require 15 - 20 mA.  This is about the same as a Tortoise.

rrinker
you do NOT have to learn how the programming works just to use it

I was referring to the act of loading the code into the Arduino - like programming an EPROM - probably an inaccurate use of the term.  Not rocket science granted, but non-trival to someone who is only marginally computer literate.

rrinker
 It never hurts to learn something new.

Unless you are one of the proverbial "old dogs".  For most of us, there some aspects of the hobby that are fun and some that are work.  There are those who would rather spend $50 than learn something new that falls into the work category.

I don't mean to argue that one of these solutions is "better" than the other.  Both are valid choices.  I'm just sharing what I believe are the points to consider when making the choice.

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Posted by jjdamnit on Saturday, September 02, 2017 3:29 PM

Hello all,

Please excuse my ignorance...but with DCC Why?

 

"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"

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Posted by maxman on Saturday, September 02, 2017 4:15 PM

jjdamnit
Please excuse my ignorance...but with DCC Why?

Because the OP said: "I know this can be done with SPST switches but I'm hoping to keep everything electronic."

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Posted by rrinker on Saturday, September 02, 2017 6:32 PM

 Because not all sound decoders start up silent. Because sometimes people punch in the wrong address on their controller. Because not everyone turns off DC mode and you can get random runaways when the system turns on. Cutting power to the staging tracks when trains are parked keeps these and any other issues at bay.

                                    --Randy

 


Modeling the Reading Railroad in the 1950's

 

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

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Posted by jjdamnit on Sunday, September 03, 2017 12:25 PM

Hello all,

rrinker
Because not all sound decoders start up silent. Because sometimes people punch in the wrong address on their controller. Because not everyone turns off DC mode and you can get random runaways when the system turns on. Cutting power to the staging tracks when trains are parked keeps these and any other issues at bay.

Just curious.

Thanks for the info.

"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"

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