Trains.com

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Simple Circuit help

4166 views
10 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    December 2004
  • From: Bedford, MA, USA
  • 21,483 posts
Posted by MisterBeasley on Thursday, December 4, 2014 7:31 AM

This is a basic LED wiring diagram.  It's drawn for a Tortoise, but you can do the same thing with a SPDT toggle.  Note that pin 5 on a Tortoise is the center (common) post of a SPDT toggle.  LEDs are polarized, so you have to be careful of which way you connect them.  As long as you've got a reasonable power supply and the resistor, though, you won't damage the LED by wiring it backwards.  It just won't work.

  

I drew this picture some time back on my computer at home, using PowerPoint.  Yesterday, I tried to re-create it at work, but they've got the "new" PowerPoint so messed up here that I couldn't figure out how to do anything but the endless bullet-charts our business thrives on.  Sorry for the delay.

It takes an iron man to play with a toy iron horse. 

  • Member since
    October 2003
  • 571 posts
Posted by hwolf on Tuesday, December 2, 2014 5:27 PM

The LEDs are already on my panel.  I have this DPDT switch handy. That is why I wanted to use the wiring diagram above. All I needed is the wiring as shown in the diagram.

Harold

  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Tuesday, December 2, 2014 5:23 PM

 Not really in this case - there is no switch motor, per the OP. This is just a toggle switch to turn on 1 LED or the other. You save one wire because of the common LEDs at the expense of having to use a DPDT toggle AND having to do the X wiring to flip polarity.

 If this were inline with a Tortoise (no resistor), or even to put parallel with the toggle switch operating a Tortoise (resistor required), I would agree, easier to use a bicolor LED.

           --Randy


Modeling the Reading Railroad in the 1950's

 

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

  • Member since
    September 2004
  • From: Dearborn Station
  • 24,281 posts
Posted by richhotrain on Tuesday, December 2, 2014 4:24 PM

It would be a lot easier, and less wiring, to just use a bi-polar (red/green) LED.

Rich

Alton Junction

  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Tuesday, December 2, 2014 4:17 PM

Found this one. You don;t even need a DPDT toggle, just a SPDT one.

http://www.grumpyoldgeek.net/images/fullcircuits_clip_image022.jpg

The web site where this appears has a lot of simple wiring explanations.

                      --Randy


Modeling the Reading Railroad in the 1950's

 

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

  • Member since
    December 2012
  • From: Mesa, AZ
  • 1,530 posts
Posted by RideOnRoad on Tuesday, December 2, 2014 3:41 PM

The wiring of the lights is illustrated in the photo. It contains DPDT switches, 1K resistors, and LEDs. I think it is the same as your drawing.

Richard

  • Member since
    October 2003
  • 571 posts
Posted by hwolf on Tuesday, December 2, 2014 3:40 PM

I have no problem with the wiring of switch machine. I have about 20. That is why I put in the drawing without a switch. I neen to know how to wire that.

Thanks

Harold

  • Member since
    December 2012
  • From: Mesa, AZ
  • 1,530 posts
Posted by RideOnRoad on Tuesday, December 2, 2014 3:10 PM

I just barely did the same thing but with two green LEDs and Tortoise motors. Here is a picture of my wiring board.

Wiring

In a nutshell, I ran the DC wires to one pole of each switch. I then ran wires to the opposite poles reversing the polarity. The center poles go to both the switch motor and to the LEDs. I took advantanges of the "diode" aspect of the LEDs, in that they only let current flow in one direction. I ran wires from the center leads on the switch to both LEDs, had them share the resistor, and reversed the polarity on the LEDs. Bottom line it worked like a champ.

Switch Board

Oh yeah, one other note, this was my first real electronics project in 30+ years. Having everything work was pretty close to a miracle.

Richard

  • Member since
    October 2003
  • 571 posts
Posted by hwolf on Tuesday, December 2, 2014 2:46 PM

You are correct.  That is exactly the way it is.

Harold

  • Member since
    December 2004
  • From: Bedford, MA, USA
  • 21,483 posts
Posted by MisterBeasley on Tuesday, December 2, 2014 2:37 PM

Just so we're perfectly clear, the idea is that you will operate the turnout and the DPDT toggle at the same time, right?  So all you need is to have the toggle turn off one LED and turn on the other?

And these are two separate LEDs, one red, one green, each with two leads?

It takes an iron man to play with a toy iron horse. 

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Users Online

There are no community member online

Search the Community

ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT
Model Railroader Newsletter See all
Sign up for our FREE e-newsletter and get model railroad news in your inbox!