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DPDT SWITCH

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DPDT SWITCH
Posted by bnsf0823 on Monday, June 13, 2016 7:16 PM

Hey, im wondering if any electicians out there can send me a diagram on how to wire a dpdt switch to operate 2 seperate devices.  Want im wanting to do is make a program/test track.  I want to wire a switch that when flipped up will give the track voltage directly from my DB150.  Then when switched down will stop power to the track and allow my program wires from pr3 to work to that same stretch of track.  I have been told that if the power to the track is on and your pr3 program wires are hooked to that then it could destroy the pr3. So i cant have any going to the pr3.  Is this even possible?  A wiring diagram would be really helpfull. Thanks 

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Posted by Mark R. on Monday, June 13, 2016 7:53 PM

Look at the six terminals on the back of the switch - hold it so there is two vertical rows of three pins.

The bottom two pins will connect to your DB150 and the top two pins will connect to your PR3. The middle two pins will go to your track.

Note - the postion of the toggle is oppostite to the pins on the rear. For example - if the bottom two pins (as per example above) are connected to your DB150, it will be connected to the track when in the UP position.

This is basically what you are doing with it ....

Mark. 

¡ uʍop ǝpısdn sı ǝɹnʇɐuƃıs ʎɯ 'dlǝɥ

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Posted by zstripe on Monday, June 13, 2016 7:54 PM

I would recommend a DPDT Center off toggle switch, so it is break before make power. Here is a link to a DPDT switch wiring. When You get to site, scroll down to DPDT switch wiring, You don't have to go far. You'll see the bottomside of the switch, with numbers on the terminals....3 and 4 go to track...1 and 2 come from the output of the DB150.... 5 and 6 come from the PR3. When toggle handle is in center, it is off, power goes nowhere.

http://www.learningaboutelectronics.com/Articles/Toggle-switch-wiring.php

Hope That Helps....should!

Take Care! Big Smile

Frank

PED
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Posted by PED on Monday, June 13, 2016 8:18 PM
This is exactly how I wired my program track so I could use a siding as my programming track OR as part of my layout. However, I used 3PDT switch (adds another set of poles to the DPDT arrangement) so that I could power a LED to use as an indicator of switch position. Green LED is normal operations and a blinking red LED is on when switch is in programming position. Be sure the section of track you are using has both rails isolated from the rest of your layout.

Paul D

N scale Washita and Santa Fe Railroad
Southern Oklahoma circa late 70's

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Posted by carl425 on Tuesday, June 14, 2016 5:25 AM
I use a 4PDT switch.  Two poles are used as above and the other two are used to switch a section of track in front of the program track off when I'm programming.  This prevents a locomotive from accidentally bridging the program track and the main.
 

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Posted by peahrens on Tuesday, June 14, 2016 8:32 AM

carl425
I use a 4PDT switch.  Two poles are used as above and the other two are used to switch a section of track in front of the program track off when I'm programming.  This prevents a locomotive from accidentally bridging the program track and the main.
 
 

Regarding the above, suggest you (OP) read the "Programming Track" section on this webpage for more understanding:

http://wiringfordcc.com/track_2.htm#d2

At the least, clearly understand the issue.  Moving a loco across the gap (between the operating and program tracks) with the DPDT in program mode means the opers power can short back to the system program circuit via the loco wheel on the gap, the prog track and the DPDT switch.  First you may think that's highly unlikely, as a loco being programmed is not moving except a tad on CV changes in some cases.  But(!), it's easy and almost bound to happen.  Say you're programming a loco, with the loco on the prog track and the DPDT in prog position.  For some reason, you take the loco off the prog track and to the workbench.  The DPDT is still in prog position.  Later, you are on another task, operating the layout with the DPDT having been left in the prog position.  And you run a loco from the non-prog track onto the prog track, the loco wheel bridging the gap so the opers juice connects back to the prog track output via the DPDT.  A potential zap to the system prog track circuitry.

I put in a simple DPDT switch, then read more about the issue.  I ordered a 4-pole switch to modify my setup for a more conservative approach.  I have not installed it because I found (talking to NCE and others) that my 5A NCE system shuts off the opers output when the program track output is active.  Most folks I talked to said that protected against the concern.  One expert said that was still not conservative enough, but I stuck with what I had.  I don't know your system, but if the opers output is active when the system prog output is active, you may want to take the most conservative steps, check with the company or other experts, or add some method of ensuring you do not have metal wheels cross the gap when the DPDT is in prog position. 

Paul

Modeling HO with a transition era UP bent

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Posted by nealknows on Tuesday, June 14, 2016 12:23 PM

Z stripe took it said it best, use the Center off toggle switch. A little bit more money, but it does the job. I use the DPDT Center off with screw terminals. This is to make it easy to replace the DPDT if there's an issue. No need to re-solder or cut off pieces of wire. I use spade connectors and it works well.

Neal

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Posted by carl425 on Tuesday, June 14, 2016 3:58 PM

zstripe
I would recommend a DPDT Center off toggle switch, so it is break before make power.

You don't need a center-off to have a break-before-make switch.

I have the right to remain silent.  By posting here I have given up that right and accept that anything I say can and will be used as evidence to critique me.

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Posted by zstripe on Tuesday, June 14, 2016 5:03 PM

carl425

 

 
zstripe
I would recommend a DPDT Center off toggle switch, so it is break before make power.

 

You don't need a center-off to have a break-before-make switch.

 

Maybe I should reinterate.....with a center-off toggle, when the toggle is in the center position, there is no path for power to follow, with a DPDT standard switch, there is a path for power, depending on which way You left the toggle. Like in the case of forgetting to turn off what You were using.

Take Care! Big Smile

Frank

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Posted by bnsf0823 on Tuesday, June 14, 2016 5:30 PM

Im glad that i posted here before i went any further! I will probably take the safest route when putting together this program/test track.  The DPDT switch sounds very simple to wire.  I do like the idea of some kind of Led's to tell me what mode that my switch is in.  Thanks again everyone.  Happy Railroading

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Posted by betamax on Tuesday, June 14, 2016 6:56 PM

https://www.dccwiki.com/Program_Track

DPDT is simple to wire, and it will be just as easy to damage your booster.

Use a 4PDT.  Never mind using two DPDT, because it is the same thing.  It will just make it easier to destroy something.

 

 

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Posted by Ron High on Wednesday, June 15, 2016 8:40 AM

The advice given by others is very good. I am not  aDCC guy just DC, but the advice a bout an isolation section as mentioned makes good sense to me.

Since you are asking about how to wire a DPDT switch i am guessing you don't know how to do much of this wiring work. Why don't you get your self a cheap volt ohm meter ( try Harbor Freight) then you can use it to meter the connections to see how they work. This would be a good way to start learning how to use a meter and do wiring. This knowledge will go a long way to help you learn wiring in this hobby.

Ron High

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Posted by Bayfield Transfer Railway on Monday, June 20, 2016 11:29 PM

The alternative to a 4PDT switch is, of course, a programming track that is not physically connected to the railroad, which is the option I use.

 

Disclaimer:  This post may contain humor, sarcasm, and/or flatulence.

Michael Mornard

Bringing the North Woods to South Dakota!

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Posted by carl425 on Tuesday, June 21, 2016 8:30 AM

Bayfield Transfer Railway

The alternative to a 4PDT switch is, of course, a programming track that is not physically connected to the railroad, which is the option I use. 

No need for a "belt and suspenders" if you don't wear pants? Big Smile

I have the right to remain silent.  By posting here I have given up that right and accept that anything I say can and will be used as evidence to critique me.

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Posted by SouthPenn on Tuesday, June 21, 2016 2:20 PM

I have a piece of track mounted right at my NCE booster. I must physically remove the engine from the layout and put it on the programing track. Really hard to forget what mode you are in.

Of course, I can still make a mess with 'Program on Main' mode.

 

South Penn
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Posted by Bayfield Transfer Railway on Thursday, June 23, 2016 10:54 PM

carl425

No need for a "belt and suspenders" if you don't wear pants? Big Smile

 
 

 

You've been watching me build?

Disclaimer:  This post may contain humor, sarcasm, and/or flatulence.

Michael Mornard

Bringing the North Woods to South Dakota!

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