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Wiring a DPST toggle switch

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Wiring a DPST toggle switch
Posted by kasskaboose on Wednesday, June 3, 2020 9:27 AM

Can anyone pls describe how to wire a DPST throttle toggle switch to isolate a block for DCC. I read about it here a bit, but it lacks a wiring schematic: http://cs.trains.com/mrr/f/88/t/248441.aspx. 

dstarr mentioned the following in that post: "Bring juice (two wires, one hot, one cold) to one SIDE of the toggle switch.  Run two feeder wires from the center contacts of the switch to the siding rails.  Keep polarity straight, you need the north rail of the siding to connect with the north rail of the main line.  If you get this wrong, trains will balk at entering the siding, or short circuit the power supply as they cross the gap.  Feeder wires can be small, 22 AWG or even 28 AWG. "

Qs based on above:

1. what about the other side of the toggle switch?

2. How do I provide power to the area once the switch is flipped off?

3. Where to connect the wires' other ends from the toggle switch?  I believe each wire goes to the buss.

Can someone pls explain more fully what to do?  I scoured the net and didn't see this schematic.  I saw what the DPST toggle switches mean and why to do it.

 

 

 

 

 

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Posted by gregc on Wednesday, June 3, 2020 10:28 AM

all you need to do it break the connection to one of the rails.   you just need a SPST switch

presumably the block is composed of one or more rails and there are one or more feeders connecting those rails to one side of a DCC bus.

separate the feeder(s) for one rails from the bus.    If it's more than one feeder, connect them together and wire to the SPST switch.   wire the other terminal of the SPST switch to the same bus those feeders were separated from.

greg - Philadelphia & Reading / Reading

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Posted by BigDaddy on Wednesday, June 3, 2020 10:44 AM

kasskaboose
2. How do I provide power to the area once the switch is flipped off?

That thread was about switching an entire layout from DC to DCC not isolating a section of rails.  We do not get the impression that is what you want to do.

The switch Greg described controls the power to one rail, that is isolated from all other rails that you don't want to switch off.  Your choices are on and off.  Off means off, like no means no.

Henry

COB Potomac & Northern

By the Chesapeake Bay

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Posted by RR_Mel on Wednesday, June 3, 2020 11:30 AM

Not sure what you want to do.

You can wire blocks several ways.

1) You can run single rail common and switch only one rail with SPST switch.

2) You can switch both rails with a DPST switch

3) I run dual mode, DC or DCC, and homerun every block back to my control panel and use a DPDT Center Off switch.  Block on, block off, block reverse.

The problem with block control is where the switch is placed.  If it is on a control panel the wires have to go from the block to the control point.  I have always wired my layouts using homeruns, that way the voltage drop at each block is about the same.

I locate my block and turnout switches in my track plan on my control panel, that way anyone can operate my layout.  My 6 year old great grand daughter can easily operate my layout.



I use mini toggles and use colored handles, blue for blocks, red for turnouts and white for lighting.


Mel


 
My Model Railroad  
http://melvineperry.blogspot.com/
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 

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Posted by chenxue on Wednesday, June 3, 2020 2:02 PM

kass,

The two center terminals on the DPDT switch connect to the two rails of your isolated section.

The two terminals on one end of the switch will go to your DCC controller or bus.

The two terminals on the other end will go to your DC powerpack or other alternate source.

Flip the switch one way, your DCC is connected and your DC is not.

Flip it the other way, your block is connected to your DC control only.

In the center position of the switch, neither source is connected to your isolated block.

My CAD is unavailable right now, but I'm sure someone can provide you a sketch...  I will check back later on.

Cid    (Memphis, Tennessee)

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Posted by chenxue on Wednesday, June 3, 2020 4:48 PM

well, that dint wurk... I'll try to see how to paste a sketch...

https://www.dropbox.com/preview/TRAINS/DPDT.png?role=personal

Cid    (Memphis, Tennessee)

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Posted by kasskaboose on Wednesday, June 3, 2020 4:53 PM

Cd: wow!  That is exactly what is needed but I have a DPST. You made the entire processs bulletproof.  Pls send along the cad or other visual. thet further solidifies things!  Thanka for trying want to email me?  my address I can provide in a private messag. 

how to address what you wrote since I ONLY run in DCC?

All: bravo all around.  Such outstanding help!

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Posted by chenxue on Wednesday, June 3, 2020 5:10 PM

Cid    (Memphis, Tennessee)

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Posted by BigDaddy on Wednesday, June 3, 2020 5:36 PM

Nope, I have a dropbox account and once I sign in, I am in my own dropbox account.

Other people without accounts don't want to sign in anyway.

The choices in posting a photo are explained in a pinned tweet in the general forum.  It has to be hosted on a free website on the internet.  Imgur.com, ImgBB.com or Flick.com
The link, if you use the photo icon, has to end in a photo-type extension like .jpg or .png

Or there is something called a BB link.  Bulletin boards were in the early days of the internet, but the link works as a copy and paste, without any icons and Flickr and Imgur can easily generate them .   It will start with (img)then the html of the pic(/img)  but the parenthesis must be brackets instead. 

 Copy and paste of just a picture does not work, neither does google of Facebook

Henry

COB Potomac & Northern

By the Chesapeake Bay

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Posted by chenxue on Wednesday, June 3, 2020 5:54 PM

https://www.dropbox.com/s/qu24mq7rfev0rx3/DPDT.png?dl=0

This link supposed to be all-share... Maybe :D

Cid    (Memphis, Tennessee)

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Posted by chenxue on Wednesday, June 3, 2020 6:13 PM

Cid    (Memphis, Tennessee)

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Posted by chenxue on Wednesday, June 3, 2020 6:19 PM

DPDT

I'll play with it some more later...

Cid    (Memphis, Tennessee)

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Posted by kasskaboose on Wednesday, June 3, 2020 6:27 PM

It works for me!  Since there is no center position b/c the toggle is DPST (just one side or the other), how would the schematic change for a DPST?  Would one set of terminals connect to the buss wires and the other to the track? 

One of the pics shows what the toggle switches looks like from the side and bottom, respectively:

https://www.amazon.com/Rocker-Toggle-Waterproof-Warranty-Ten-1221/dp/B07D74HL8B/ref=sr_1_1?dchild=1&keywords=dpst&qid=1591226894&sr=8-1

 

Thanks everyone for the help!  I'm all set now.

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