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Wiring advice LEDS, resistors and slide switches

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Wiring advice LEDS, resistors and slide switches
Posted by Matt'sdad on Wednesday, August 21, 2019 2:37 PM

I am planning to use SPDT slide switches for my N Scale turnouts.  I am using Walthers system for the the mainline but will control the yards manually.  My plan is to use two bi-color LEDs per turnout to indicate turnout position.  Any advice on LED-resistor combination, wiring diagram and where to purchase would be helpful.  Links to previous threads work as well.  Thanks in advance for the help.

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Posted by Mark R. on Wednesday, August 21, 2019 4:04 PM

You can search the community yourself using the search box on the right instead of asking others to do it for you.  ;-)

Mark.

¡ uʍop ǝpısdn sı ǝɹnʇɐuƃıs ʎɯ 'dlǝɥ

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Posted by RR_Mel on Wednesday, August 21, 2019 4:10 PM

What switch machine do you plan on using?
 
SPDT slide switch indicates a dual coil switch machine.  To operate LED indication they need contacts on the switch machine.  A Tortoise requires a DPDT switch and a bicolor LED will work in series with the Tortoise.
 
We need more info.
 
 
Mel
 
 
My Model Railroad   
 
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Posted by Matt'sdad on Wednesday, August 21, 2019 4:37 PM

I am using a slide switch to manually control the turnouts.  No switch machines. 

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Posted by Matt'sdad on Wednesday, August 21, 2019 4:43 PM
Thanks Mark. I am aware of the search box. Sorry I wasn’t clear. I wasn’t asking for people to search for me - just hoping someone had a similar thread bookmarked or saved.
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Posted by SeeYou190 on Wednesday, August 21, 2019 4:46 PM

To control a bi-color LED you need a DPDT set of contacts set up as a reversing switch.

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If the Walthers machine can operate with SPDT contacts (I have never used one, so I do not know for certain), the easiest way would be to use a 3PDT slide switch, and use the additional contacts as a DPDT reversing switch.

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The Circuitron Tortoise has two sets of SPDT contacts that can be used as a DPDT switch for this purpose, but again, I am not sure what auxiliary contacts are available on the Walthers switch motor.

.

-Kevin

.

Wink Happily modeling my STRATTON & GILLETTE RAILROAD. A Class A line located in a personal fantasy world of semi-plausible nonsense on Tuesday, August 3rd, 1954.

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Posted by RR_Mel on Wednesday, August 21, 2019 4:53 PM

Gotcha.  I would use a three wire red green LEDs, they come in either common Anode or common Cathode.  The center pole on the SPDT switch to the power supply then one of the switched legs to each of the outside LED leads.
 
  
 
The value of the resistor depends on the supply voltage, normally a 1KΩ resistor in either the positive or negative lead would work.
 
 
 
 
Mel
 
 
My Model Railroad   
 
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I'm beginning to realize that aging is not for wimps.
 
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Posted by York1 on Wednesday, August 21, 2019 5:08 PM

Mark R.
You can search the community yourself using the search box on the right instead of asking others to do it for you.  ;-)

 

The problem may be that the forum's search is not easy to use.

Saints Fan John

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Posted by Matt'sdad on Wednesday, August 21, 2019 5:20 PM

That’s what I find.  Mel might have me on the right path, thanks.

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Posted by Matt'sdad on Wednesday, August 21, 2019 5:30 PM

Thanks Mel, that’s making some sense.  Two questions:

1. I was hoping to use two bi-color LEDs per turnout, one for the main, one for the diverging.  Does that mean I need a DPDT?

or

2. I thought I remembered a diagram using two 2-lead bi-color with one lead from each soldered together.  Is that possible?

Thanks again, the electrical aspect of the hobby is interesting but all new to me.  I’m more from the artistic/scenery side.

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Posted by RR_Mel on Wednesday, August 21, 2019 5:42 PM

You only need one color at a time?  Red for diverging and green for straight, correct?
 
The three lead LED is a bicolor LED.
 
The three lead LEDs will light up Red or Green depending on which position the switch is in.  If you need more than one indicator parallel them.  Both reds together both greens together and both commons to separate 1KΩ resistors to the power supply.
 
 
 
Mel
 
 
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I'm beginning to realize that aging is not for wimps.
 
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Posted by Matt'sdad on Wednesday, August 21, 2019 6:00 PM

Thanks Mel, makes sense.  I’ll check out the site you posted and get a few to try.  Appreciate the info!!

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Posted by RR_Mel on Wednesday, August 21, 2019 6:13 PM

Matt'sdad

Thanks Mel, makes sense.  I’ll check out the site you posted and get a few to try.  Appreciate the info!!

 

I was getting confused!  I only use one indication for each turnout.  A single bicolor LED, green for straight through and red for diverted.  I don’t understand why you are thinking two LEDs.
 
 
Mel
 
 
My Model Railroad   
 
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I'm beginning to realize that aging is not for wimps.
 
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Posted by SeeYou190 on Wednesday, August 21, 2019 7:30 PM

The common anode or cathode LEDs that Mel described can be wired with SPDT contacts. If the Walthers switch motor only needs SPDT contacts, then you can do both with a common DPDT slide switch.

.

I also do not understand why you need two LEDs per turnout.

.

-Kevin

.

Wink Happily modeling my STRATTON & GILLETTE RAILROAD. A Class A line located in a personal fantasy world of semi-plausible nonsense on Tuesday, August 3rd, 1954.

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Posted by rrinker on Wednesday, August 21, 2019 9:09 PM

 Same reason I use 2 LEDs per turnout. On my panel there is an LED in each of the diverging routes in the schematic. The selected track is green, the other route is red.

 If there is only one LED, and it's either red or green, how do I know which way the switch is actually lined? The 'normal' or green one isn't always the straight leg of the turnout!

 The other alternative would be two single color LEDs, where the selected route is lit up and the other route remains dark. Still 2 LEDs.

                                --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 Matt'sdad on Wednesday, August 21, 2019 10:12 PM

Thanks Randy,

I’ve read many of your posts and always enjoy them.  You described what I was thinking and what I was hoping to do.  Pretty sure I understand wiring two single color LEDs to one SPDT.  But back to original question: how to wire two bi-color LEDs?

- is the SPDT the right switch for two bi-color? Reminder, the SPDT will be controlling the turnouts via stiff wire (which I did on my previous layout, just no LEDs)

- do I need the 3-lead LED or will the 2-lead work?

- Any advice on wiring is appreciated.  Thanks for chiming in and helping!!

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Posted by SeeYou190 on Thursday, August 22, 2019 6:39 AM

rrinker
 Same reason I use 2 LEDs per turnout. On my panel there is an LED in each of the diverging routes in the schematic. The selected track is green, the other route is red.  If there is only one LED, and it's either red or green, how do I know which way the switch is actually lined? The 'normal' or green one isn't always the straight leg of the turnout!

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That makes sense. I have only seen a few layouts with indicators in the panels, and green was always "main" and red was "diverging" whether or not main was the straight route or not.

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I have used DPDT toggles to control switch machines ever since the Tortoise came out. The position of the toggle handle has been the only indicator I have needed.

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If turnouts can be controlled for a CTC board or other remote location, I can certainly see where panel indicators would be nice.

.

If I need a visual indicator for a turnout I install a signal on the layout to show the turnout position. This bothers some purists, because my signals have nothing to do with train control.

.

-Kevin

.

Wink Happily modeling my STRATTON & GILLETTE RAILROAD. A Class A line located in a personal fantasy world of semi-plausible nonsense on Tuesday, August 3rd, 1954.

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Posted by rrinker on Thursday, August 22, 2019 6:56 AM

Matt'sdad

Thanks Randy,

I’ve read many of your posts and always enjoy them.  You described what I was thinking and what I was hoping to do.  Pretty sure I understand wiring two single color LEDs to one SPDT.  But back to original question: how to wire two bi-color LEDs?

- is the SPDT the right switch for two bi-color? Reminder, the SPDT will be controlling the turnouts via stiff wire (which I did on my previous layout, just no LEDs)

- do I need the 3-lead LED or will the 2-lead work?

- Any advice on wiring is appreciated.  Thanks for chiming in and helping!!

 

3 lead ones will work with a SPDT switch. The center is the common, both of those tie together and go to one side of the power supply (depends on if they are common anoode or common cathode). You can also put the resistor in this lead (one per LED) but if there is a difference in the brightness of the green vs red, you can use two resistors per LED, each a different value, one in the red leg and one in the green leg. The other side of the power supply goes to the center terminal of the SPDT. The red lead of one LED and green lead of the other LED goes to one outer terminal oof the SPDT, and the remaining two leads go to the other terminal of the SPDT. Thrown one way, one LED will be green and the other red. Flip the slide switch the other way, and the green LED will now be red, and the red LED will now be green.

 To make it work with 2 wire bicolor LEDs, you need an AC power supply and a couple of extra regular diodes, or a DPDT slide switch.

                              --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 rrinker on Thursday, August 22, 2019 7:01 AM

SeeYou190

 

 
rrinker
 Same reason I use 2 LEDs per turnout. On my panel there is an LED in each of the diverging routes in the schematic. The selected track is green, the other route is red.  If there is only one LED, and it's either red or green, how do I know which way the switch is actually lined? The 'normal' or green one isn't always the straight leg of the turnout!

 

.

That makes sense. I have only seen a few layouts with indicators in the panels, and green was always "main" and red was "diverging" whether or not main was the straight route or not.

.

I have used DPDT toggles to control switch machines ever since the Tortoise came out. The position of the toggle handle has been the only indicator I have needed.

.

If turnouts can be controlled for a CTC board or other remote location, I can certainly see where panel indicators would be nice.

.

If I need a visual indicator for a turnout I install a signal on the layout to show the turnout position. This bothers some purists, because my signals have nothing to do with train control.

.

-Kevin

.

 

 In this case the OP isn;t using the slide switches to control something else, the slide switch IS the point motor. Usually the contacts are used for frog polarity, but with some LEDs attached they cna make signals the same way you do, not prototypically correct but it would shoow a red signal along the track that a train would derail if it ran the open points, and a green along the way it can go safely. Or panel lights, or whatever.

 DIY version of a Bluepoint or Bullfrog type of thing. Can be controlled from the fascia by rigging a rod and a knob on the end to push/pull to move the slide switch, with another hole drilled in the handle at right angles using a piece of music wire stuck up through the throwbar.

                                           --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 RR_Mel on Thursday, August 22, 2019 9:45 AM

Thank you Randy
 
I have never had a layout of my own that had the diversion as the main route but I can see how that would be better if I did.
 
Sorry Matt’sdad if I lead you astray!  I would still use the three lead bicolor LEDs and simply reverse the LED wiring on the straight through.
 
 
I redid the drawing with the resistor in the common leg of the three lead bicolor LED.
 
 
Mel
 
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 
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Posted by Matt'sdad on Thursday, August 22, 2019 8:41 PM
Just got home, traveled all day from CA to PA. I’ll take a good look at the posts tomorrow. Thanks for all the info & help. Never ceases to amaze how much info is out there & everyones willingness to help. Great hobby!!
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Posted by SeeYou190 on Friday, August 23, 2019 12:42 PM

Matt'sdad
I am planning to use SPDT slide switches for my N Scale turnouts.  I am using Walthers system for the the mainline but will control the yards manually.

rrinker
 In this case the OP isn;t using the slide switches to control something else, the slide switch IS the point motor.

.

OK, I completely misunderstood.

.

I took the statement above to mean that the slide switches were being used for the new Walthers switch machines.

.

-Kevin

.

Wink Happily modeling my STRATTON & GILLETTE RAILROAD. A Class A line located in a personal fantasy world of semi-plausible nonsense on Tuesday, August 3rd, 1954.

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Posted by BroadwayLion on Saturday, August 24, 2019 9:43 AM

 

 

 

ROAR

The Route of the Broadway Lion The Largest Subway Layout in North Dakota.

Here there be cats.                                LIONS with CAMERAS

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Posted by Matt'sdad on Wednesday, September 04, 2019 3:39 PM
Appreciate all the input. I am looking for a good source for LEDs, switches etc. Any Recommendations? I have looked at All Electronics, no reply to my email however. Also, any recommendations on a power source for the LEDs?

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