Street light controller

ModelRailroadForums.com is a free Model Railroad Discussion Forum and photo gallery. We cover all scales and sizes of model railroads. Whether you're a master model railroader or just getting started, you'll find something of interest here.


Red Oak & Western

Active Member
Working on a project for one of my other hobbies, I dragged (drug?) out all my electronics experimenter supplies. (I'm building a Time Domain Reflectometer to get my ham station ready for winter.) That got me to thinking what I could build as accessories for the railroad.

I recently received a shipment of street lights I purchased on eBay, and I am really pleased with them.



So to make turning them on and off easier, and make the under layout wiring cleaner, I designed a driver circuit so that a single panel switch would be able to turn up to 10 lights on and off. The quantity 10 is just an arbitrary number based on how many drivers would fit onto a specific circuit board size. I tested the design and it does just what I wanted it to do – flip one switch and all the streetlights in one area come on. That was followed by – why not have the lights controlled by a photo sensor – it gets dark, and the lights come on automatically. So I designed and prototyped an electronic switch using a photoresistor. Dark = on, light = off. Everything is working so far.

Playing with it brought up the question: Do street lights come on gradually? It's be so long since we have lived in an area that has street lights, I don't remember. I vaguely remember the street light in front of my childhood home flickering blue as it came on, then it burst into bright white. But the town changed the type of bulb so that it was more of an orange, and I don't remember how it came on, only that it gave off weird looking light.

I'm inclined to give them a "soft start", that is, take about a second to transition from full off to full on.

Any ideas or comments?
 

logandsawman

Well-Known Member
Yes, they do come on gradually in the real world. And go off gradually as well, although not so much as coming on.

As far as lighting the lights, I put all my lights, street and building, on one switch. For ease of operation.

night scenes 006.JPG-1000x0.jpg
 

Iron Horseman

Well-Known Member
Playing with it brought up the question: Do street lights come on gradually?
That depends on the type of lamp. In general, "Yes", but that is only because of the nature of the old sodium arc and mercury arc lamps. I think one of these types of lamps can take up to 5 minutes to come to full brightness, so on the model the transition period should depend on the speed of your fast clock.

The really old electric street lamps (the ones that replaced kerosene) used to just have an Edison incandescing bulb in them. Those would have been instantly full brightness.

In a juxtaposition the really new street lamps are instant on. Don't know what technology they use.
 
Last edited by a moderator:

wombat457

Well-Known Member
Staff member
I also have all of my street lights on one wire so they all come on and go off together. I like the idea of the "light sensitive on/off idea though, that does sound interesting.

As for street lights in the real world coming on gradually or completely. I'm not all that sure if they do come on gradually in reality OR if they only appear to as it gets darker. Naturally, that will depend on the bulb type used. Those that need to "heat up" will naturally appear to come on slowly or a fluorescent globe will flicker before coming to full life.

What they use in modern street lights is unknown to me so I can't really say one way or the other; however, I would imagine that for a street light to come on "gradually" wouldn't it need to be connected to a dimming system of some type that controls how fast or slow they come to full operating power?
 

Red Oak & Western

Active Member
however, I would imagine that for a street light to come on "gradually" wouldn't it need to be connected to a dimming system of some type that controls how fast or slow they come to full operating power?
Oh, the miracle of modern (and not so modern) electronics. These particular street lights have incandescent bulbs. So that's fairly easy - by using an RC (resistor/capacitor) timer circuit, the driver transistors can be transitioned from fully off to fully on over any desired time period.

I've got some different style street lamps that use LEDs - they're a little more difficult. LEDs operate over a very narrow voltage range, so to dim them, they are switched on and off at a varying rate (called Pulse Width Modulation {PWM}). But the concept is the same, drive the pulse width modulator with a simple timer so that over the desired time period, the pulses go from very narrow to continuous.

And while I think about it, it wouldn't be that hard to tie the "gradualness" of the off/on transition to the photo sensor. If it gets dark fast, the street lights come on fast. If the room slowly gets dark, the lights come on slowly. I'm just not sure how realistic that would be. A little research showed all sorts of different control systems. Some systems have sensors on the individual street lights. Other systems have a master relay box that starts a group of lamps at some predetermined point - either light levels of time or a combination of both.
 
Last edited by a moderator:

wombat457

Well-Known Member
Staff member
The only street lights we have were put in just after Noah decided to build an Arc so I am a little behind the times :)
 

cmaceeepc

Member
Well with all this talk of lighting I would like to brag that we have had LED street lights installed about 3 weeks ago - Cranbourne, Melbourne, Australia - a big upgrade to the old really dull ones we used to have
 

Mark R.

Custom Painter
I created a simple circuit that closes a relay through an adjustable photo-cell. I have six circuits / six relays, each of which are set to turn on at slightly different levels of light. I mounted the board with the six photo-cells in the side of a hill so they get a good "look" at the room lights. I have a 2000 watt rotary dimmer switch that controls the room lighting. To that I mounted a very slow rpm drive motor to turn the dimmer switch - it takes about five minutes from full brightness to "night" (which isn't off, but just barely on, so you can still see what you're doing).

As the room lights begin to dim, the photo-cells start to trip the relays which are connected to random building lights and street lights. Makes for a very cool effect as the lights go down and the layout comes to life with lights.

Mark.
 

trailrider

Well-Known Member
I'm not just sure when mercury arc bulbs came into general use, especially in smaller cities. I do recall that the lights on my block in what is now a "free-fire zone" in a major midwest city came on all at once back in the late '40's, early '50's, so they must have been incandescent. Had to pay attention because I had to come home when the street lights went on! (That was when kids could play outside in the vacent lot without fear of being kidnapped or shot! :( ) Since I model that period on my layout, my lights are also incandescent, and controlled by a SPST toggle on the control panel(s). Due to the configuration of the layout it was easier to connect strings to 9-12v wall plugs in a given area, with a switch located on the separate control panel or hidden directly on the layout (one is in a yard, using a slide switch from my parts box, another toggle switch is mounted on the roof of a yardmaster's office and looks like an exhaust pipe). I also have an operating traffic signal run by a Model Power module. That is on a separate circuit and toggle. Kinda neat!
 

tootnkumin

Well-Known Member
Staff member
Back in your day, trailrider (and mine) they were incandescent and came on in sections around the town to avoid a sudden load on the system. The blue mercury lights were introduced at the intersections of main roads first where I was (Auckland NZ) about 1960, extending to the connecting main roads over time, Didn't seem to be all that long before they changed to the yellow types. We've also just here in my local neighbourhood, got the LED's installed.

Could tell a story about the blue mercury ones, but as it comes under the heading of "The Twilight Zone", I'll reserve it.
 

new guy

Active Member
Back in your day, trailrider (and mine) they were incandescent and came on in sections around the town to avoid a sudden load on the system. The blue mercury lights were introduced at the intersections of main roads first where I was (Auckland NZ) about 1960, extending to the connecting main roads over time, Didn't seem to be all that long before they changed to the yellow types. We've also just here in my local neighbourhood, got the LED's installed.

Could tell a story about the blue mercury ones, but as it comes under the heading of "The Twilight Zone", I'll reserve it.
In the 70's we had a style of streetlights here in Lansing that would go out for about a minute if you gave em a good open hand SMACK!

Was fun to ride a bike down the block at night, smack em as you go and leave a trail of DARK!
 

wombat457

Well-Known Member
Staff member
After reading some of the posts (well all of them actually) I am feeling so inadequate with my lighting only on an on/off toggle switch :(
 

new guy

Active Member
After reading some of the posts (well all of them actually) I am feeling so inadequate with my lighting only on an on/off toggle switch :(

Don't sweat it! I will have NO lights, MUCH track but my scenery will NOT be near what YOU have achieved, EVER!

Talk to me NOT of 'inadequate' feelings!
 




Affiliate Disclosure: We may receive a commision from some of the links and ads shown on this website (Learn More Here)


ModelRailroadForums.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com

RailroadBookstore.com - An online railroad bookstore featuring a curated selection of new and used railroad books. Railroad pictorials, railroad history, steam locomotives, passenger trains, modern railroading. Hundreds of titles available, most at discount prices! We also have a video and children's book section.

ModelRailroadBookstore.com - An online model railroad bookstore featuring a curated selection of new and used books. Layout design, track plans, scenery and structure building, wiring, DCC, Tinplate, Toy Trains, Price Guides and more.

Top