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!

Walthers HO traffic lights - wiring to custom controller

7205 views
19 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    October, 2011
  • 51 posts
Walthers HO traffic lights - wiring to custom controller
Posted by BMR777 on Thursday, October 06, 2011 9:58 PM

Has anyone here been able to wire the Walthers HO traffic lights to a custom controller?  I'm considering the purchase of these and hooking them up to an Arduino microcontroller to have a custom traffic light sequence / setup, but I can't seem to find anything online about the voltage for these lights and whether or not a resistor would be required or if there is one already pre-wired into the lights.

Anyone know the voltage or whether the lights are pre-wired with resistors?  Would anyone be kind enough to upload the manual for the lights?

Thanks!

Long live the J!

  • Member since
    December, 2004
  • From: Bedford, MA, USA
  • 17,905 posts
Posted by MisterBeasley on Friday, October 07, 2011 2:18 PM

I tried to do this with a controller from Bakatronics.  It was a kit that only cost a few dollars.

Untortunately, I discovered that the circuit was for a common-cathode arrangement, but the Walthers traffic lights are common-anode.  I looked into re-designing the circuit to flip the polarity, but it just wasn't practical.

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

  • Member since
    October, 2011
  • 51 posts
Posted by BMR777 on Friday, October 07, 2011 3:19 PM

Thanks for the replies.

MisterBeasley, I actually want to hook the lights up to the Arduino which from what I have read can handle the common anode lights just fine.  It's just a matter of hooking these up without burning out the bulb that has me.  I'm not so good at the electrical wiring aspect of Model Railroading.

I asked about the resistor because I thought I heard somewhere they had resistors pre-wired, but I can't seem to find any information supporting this.

Thanks!

 

Long live the J!

  • Member since
    October, 2005
  • From: Ulster Co. NY
  • 1,462 posts
Posted by larak on Friday, October 07, 2011 4:34 PM

You could just feed the output(s) through an inverter Chip or a single transistor stage. A quad inverter might be easiest.

The mind is like a parachute. It works better when it's open.  www.stremy.net

  • Member since
    December, 2004
  • From: Bedford, MA, USA
  • 17,905 posts
Posted by MisterBeasley on Friday, October 07, 2011 7:47 PM

I thought of that, but inverters flip logic levels, not output voltage.  If I tried that, I'd end up with 2 lights on each side on all the time, not what I wanted.

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

  • Member since
    February, 2002
  • From: Reading, PA
  • 24,759 posts
Posted by rrinker on Friday, October 07, 2011 8:40 PM

7406 and 7407 inverter/drivers are open collector outputs and shoudl work for this. Output of controller goes high to turn on a particualr light for the common cathode arrangment, throught he buffer/driver this turns on the current sink connected to the cathode of the particular LED and essentially grounds it, turning it on.

                                   --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, 2007
  • 939 posts
Posted by hobo9941 on Sunday, October 09, 2011 1:10 AM

I have the Walthers traffic lights and controller. The controller works on 18 volts, AC. There are no resistors in the traffic lights themselves. They work just fine with the Walthers traffic light controller. Not sure why you would want to make it more complicated.

  • Member since
    December, 2004
  • From: Bedford, MA, USA
  • 17,905 posts
Posted by MisterBeasley on Sunday, October 09, 2011 8:15 AM

In the end, I chose the simple route, too.  I just bought the Walthers controller.  If you wait for the Walthers flyer every month, sooner or later it will go on sale.  Not right now, though.  If it's any consolation, it works very nicely.

The controller is said to operate two complete 4-way intersections.  I have two 3-way intersections on my layout, and I'm about to add a third.  Does anyone have any experience running these controllers above their rated number of lights?

Also, note the statement about the 18VAC.  The controller does not come with a power supply, so that's something else you need to consider.  I use an old train transformer.

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

  • Member since
    October, 2011
  • 51 posts
Posted by BMR777 on Sunday, October 09, 2011 2:15 PM

Thanks for the info.

What I wanted to do was have some custom traffic light poles printed from a 3D printer and mount the walthers hanging traffic lights to them.  Then I wanted to have the prototypical sequence of my area, where first the left hand lanes get the green, then the rest of the traffic.  I haven't seen this setup yet with the Walthers controller.

I also wanted to have a red light camera 3D printed and try mounting a bulb in there somehow and have the Arduino flash the red light camera bulb once in a while when the light was red.  Also, I wanted to eventually tie all this into a railroad crossing so that the lights also turn red when the crossing is active. 

It seems like a lot, but since you can run your own code on the Arduino to get it to do what you want it to I think this is possible.  The only challenge for me is the more mechanical stuff.

The Walthers traffic control unit just doesn't seem "real" enough for me.

For the Walthers traffic control unit, is the output voltage 18V, or is that just the input?  The Arduino by comparison outputs 5V.

Long live the J!

  • Member since
    December, 2004
  • From: Bedford, MA, USA
  • 17,905 posts
Posted by MisterBeasley on Monday, October 10, 2011 6:59 AM

BMR777

For the Walthers traffic control unit, is the output voltage 18V, or is that just the input?  The Arduino by comparison outputs 5V.

The Walthers controller needs an input voltage of 18V.  I don't know what the output is.  I can check that later if nobody else comes up with the answer before tonight.

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

  • Member since
    October, 2011
  • 51 posts
Posted by BMR777 on Monday, October 10, 2011 6:50 PM

That would be great if you could post that.  Thanks!

Long live the J!

  • Member since
    December, 2004
  • From: Bedford, MA, USA
  • 17,905 posts
Posted by MisterBeasley on Monday, October 17, 2011 8:01 PM

I put a meter on the outputs of the Walthers traffic light controller.  I got 2.5 to 2.9 volts, depending on which setting I had my cheapo voltmeter on.  This controller is driving 6 faces (3 lights at each of 2 intersections.)

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

  • Member since
    October, 2011
  • 51 posts
Posted by BMR777 on Wednesday, October 19, 2011 8:58 AM

Thanks for posting!

I actually got a reply from Walthers yesterday as well, saying that the light bulbs are 1.5 volt bulbs and have no resistors.  Seems odd though since your setup is outputting more than that.

Long live the J!

  • Member since
    February, 2002
  • From: Reading, PA
  • 24,759 posts
Posted by rrinker on Thursday, October 20, 2011 7:18 AM

 Probably 2 are wired in series , which woud make the voltage almost perfect, slightly below rated to ensure a long bulb life.

                       --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, 2004
  • From: Bedford, MA, USA
  • 17,905 posts
Posted by MisterBeasley on Thursday, October 20, 2011 10:05 AM

I don't think they're in series, because the lights on the 2-face units are just as bright as the lights on the single-face units, and there's no difference in wiring.  I suppose they could have used 3-volt LEDs for the 1-face models and series-wired 1.5 volt LEDs for the 2 and 4 face ones, but I would imagine that they would rather stick to a single LED type for all the models.

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

  • Member since
    February, 2002
  • From: Reading, PA
  • 24,759 posts
Posted by rrinker on Thursday, October 20, 2011 1:39 PM

Hmm, interesting, as 2.9V is too high for anything but a white LED. However - it could be pulsed, depends on how many wires are going from the controller to the lights. Like the Digitrax signal controller, where 10 wires drive 12 LEDs.A common circuit design to do this sort of thing with LEDs is called 'Charlieplexing'. Since LEDs are diodes, you can do 'wild' things like hooking two two a single output, ine by cathode and the other by anode, then connect the free swide of each LED to the appropriate + or - power supply terminal. If the output is low, one LEDs lights. When the output goes high, the other one lights up. 2 indications, one output.

               --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
    July, 2006
  • 44 posts
Posted by KidatHeart06 on Friday, April 18, 2014 5:37 PM

Hi, Thanks for getting back to me about this. What I was asking was if you ever got them to work the way you wanted. If you did, great. If not, I found a way to comtrol them and set the timing to whatever you want.  Let me know if you're interested.  George

 

Modeling the B&O in the 50-60's

  • Member since
    July, 2006
  • 44 posts
Posted by KidatHeart06 on Friday, April 18, 2014 5:40 PM

I wrote a program and got them to work with an Arduino. Let me know if you're still wanting to do this and I can pass on the info

Modeling the B&O in the 50-60's

  • Member since
    November, 2013
  • 1 posts
Posted by don17313 on Monday, April 09, 2018 2:50 AM

I have just successfully hooked up the Walthers traffic lights to an Arduino UNO. 

video: https://youtu.be/7PL6BuR2FSYand 

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!