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3PDT (on)-off-(on)

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3PDT (on)-off-(on)
Posted by Paul Schulze on Sunday, May 13, 2018 1:34 AM

Does anyone know where I can purchase mini toggle 3PDT (on)-off-(on) switch?  I would like to manually control three turnouts at one time with a single switch or individually with a separate dedicated switch.  A SPDT momenarty will activate cause all thee turnouts to be activated if either the group switch or individual switch is thrown.  My Google search seems to not be bringing any minis up (1/4" hole for the switch).

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Posted by rrinker on Monday, May 14, 2018 12:02 PM

This sounds like a job for a diode matrix rather than a rather oddball switch. 

What is the track arrangement here, where you would sometimes want to throw all 3 the same way, but other times throw each of them individually?

                             --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 BigDaddy on Monday, May 14, 2018 12:11 PM

Henry

COB Potomac & Northern

By the Chesapeake Bay

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Posted by RR_Mel on Monday, May 14, 2018 12:21 PM

The switch that Henry linked to doesn’t say it’s momentary, if you are using solenoid switch machines you must have a momentary on in both directions.
 
 
 
I use them and keep spares in stock.
 
 
Mel
 
Modeling the early to mid 1950s SP in HO scale since 1951
  
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 
 
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Posted by Paul Schulze on Monday, May 14, 2018 1:23 PM

rrinker

This sounds like a job for a diode matrix rather than a rather oddball switch. 

What is the track arrangement here, where you would sometimes want to throw all 3 the same way, but other times throw each of them individually?

                             --Randy

 

 Website: http://http://www.clearstarrynights.com/timberrock/train/index.html on right side.

Path top green S67 to S78 to S76 and S68 to S78 to S76 each have three turnouts.

Path bottom red and black S67 to S667R to S68 and S67 to S667R to S76

I may not need the indiviual switches after having looked at this more.

Any thoughts or comments?

 

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Posted by gregc on Monday, May 14, 2018 5:16 PM

i assume each turnout has two coils that could be controlled with a momentary DTSP switch.

as Randy suggested, couldn't a single SPST or push-button momentary switch be used for each path with a diode between the switch and each turnout coil to be powered to switch the turnout.

The diodes provide power to all the turnouts and allow the turnouts to be controlled with individual SPDT momentary switches, preventing the indivual switches from powering more that one turnout.

multiple SPST switches can be connected to the same turnout coil through separate diodes.

greg - Philadelphia & Reading / Reading

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Posted by BigDaddy on Monday, May 14, 2018 6:01 PM

He didn't ask for a momentary 3p switch.  But I'm still lost, maybe that's what he needs

gregc
The diodes provide power to all the turnouts and allow the turnouts to be controlled with individual SPDT momentary switches, preventing the indivual switches from powering more that one turnout.

Greg you lost me here.  He want a switch that powers all 3 turnouts, which seems to be in conflict with this paragraph.  Type slowly so I can understand.  Big Smile

 

Henry

COB Potomac & Northern

By the Chesapeake Bay

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Posted by rrinker on Monday, May 14, 2018 6:06 PM

 If the red line at 8 or the green line at 7 are long enough to hold a train, there might be a reason to switch S67, S68, and S78 independently because a train could leave at S67 while another enters at S68, or a train could leave at both S67 and S68. S76 should be independent of S78, because if you throw S76 and not S75 then at S78 could go either way depeneding on where you want the train to go.

                                       --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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  • From: somerset, nj
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Posted by gregc on Monday, May 14, 2018 6:15 PM

RR_Mel
The switch that Henry linked to doesn’t say it’s momentary,

Paul Schulze
I would like to manually control three turnouts at one time with a single switch or individually with a separate dedicated switch.  A SPDT momenarty will activate cause all thee turnouts to be activated if either the group switch or individual switch is thrown. 

he wants to be able to control each turnout individually with a switch and a group of turnout to a particular route with a separate switch.

if the turnout machines are the twin coil type (not Tortoise), then a momentary switch could be used to power one coil on each of several turnouts to select a particular route.   This would connect those turnouts together and they couldn't be controlled individually.

by adding a diode between the common switch and coil, the individual switch could provide power to the coil and the diode would block it (if it is DC) from reaching the group of turnout coils connected by the common switch.

BigDaddy
Type slowly so I can understand. 

does this explain things well enough?

greg - Philadelphia & Reading / Reading

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Posted by BigDaddy on Monday, May 14, 2018 6:31 PM

gregc
by adding a diode between the common switch and coil, the individual switch could provide power to the coil and the diode would block it (if it is DC) from reaching the group of turnout coils connected by the common switch. 

does this explain things well enough?

Maybe.  There is a common switch, a diode ( or 3 diodes?) to each coil, and it controls all 3 at once. 

The individual switch goes to the coil (3 switches, 3 coils) and the diode prevents current from traveling along the common switch wiring to activate other coils?

 

Henry

COB Potomac & Northern

By the Chesapeake Bay

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Posted by gregc on Monday, May 14, 2018 6:48 PM
i think you follow.  this diagram may help.
the diode is ">|", current passes left to right.


V+ --- sw ------------- coil ---- Gnd | | | |-->|--| | | |-- sw --| | | | |-->|--| | | |- sw ------------- coil ---- Gnd

 

greg - Philadelphia & Reading / Reading

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Posted by BigDaddy on Monday, May 14, 2018 6:57 PM

Got it, thanks Greg

 

Henry

COB Potomac & Northern

By the Chesapeake Bay

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Posted by Paul Schulze on Tuesday, May 15, 2018 12:19 AM

http://www.clearstarrynights.com/gifs/switches.jpg

This is an example of one path controlled by a single switch throw.  I can control three different turnouts and hence a different path using the opposite throw of the 3PDT switch - a maximum of six turnouts on two different routes with one switch and no diodes.  That is why I wanted the 3PDT (on)-off-(on) switch.  The down side is that I might have to use the individual DPDT switches to return the turnouts to their original configuration if desired unless the back-throw of the first 3PDT or a second 3PDT switch is used.  

I think this can be very useful if the routes are carefully chosen.  Thoughts?

I appreciate the great discussions.

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Posted by gregc on Tuesday, May 15, 2018 10:00 AM

a 3PDT switch limits you to 3 turnouts, which may not be a problem, and, as you said, can possibly be used for a 2nd route.   Additional routes require more switches.   And the switches may be hard or $$ to obtain.

as discussed, a single momentary switch with diodes can support > 3 turnouts.   A single push-button switch can be located independently of other routes.   A push-button switch should be easier to obtain and < $$.   diodes can be had for about 0.10 a piece.

based on the trackage and turnout mentioned, it seems that there is a need for 3 routes: 1 to enter the looped (at least S67), a 2nd remain in the loop (S78 and S68), and a 3rd to exit the loop (S78 and S67).   There may be a separate set of routes and switches depending on S66. 

greg - Philadelphia & Reading / Reading

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Posted by Paul Schulze on Tuesday, May 15, 2018 11:48 AM
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Posted by RR_Mel on Tuesday, May 15, 2018 5:43 PM

I use the DPDT and 3PDT Momentary switches as a route select.  It is a separate switch that parallels the existing SPDT momentary switches.  No diodes needed nothing complicated just a route switch.  The regular switches still work.
 
Diodes would work OK for DC power but I use 18 volts AC for my solenoid switch machines.  Using AC prevents residual magnetism build up on the plungers.  Many years ago I had problems with residual magnetism in my Atlas switch machines and went with AC and it has worked so good that I stayed with it.
 
I like the 60Hz buzz when they’re activated, I know the switch machine got the command
 
It works great for me.  I haven't replaced a switch machine since I cut over to AC in about 25 years.   I do have one Tortoise operating my double crossover on DC. 
 
 
 
Mel
 
Modeling the early to mid 1950s SP in HO scale since 1951
  
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 

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