Operating N-Scale Traffic Lights

Are these the smallest set of operating traffic lights in the world?

I wanted to have a set (or two!) of operating traffic lights on my NTRAK module but commercially made traffic lights available in hobby stores (eg Model Power) did not appeal as they were grossly overscale.

The only way to own an accurately scaled and correctly operating set was to build them myself! So I decided to scratch build a set on a box lid as a test run. These photos show the results.

These traffic lights were built out of 1/16th brass tube.
The anode legs of 1mm "miniature" red, orange and green LEDs were (very carefully) soldered on to the brass "poles" (which act as a "common"). Then three lengths of very fine enamelled winding wire were fed through each pole, out a notch on the back of the pole and (again, very carefully!) soldered on to the cathode leg of each LED - one to red, one to amber and one to green.
Care was taken to ensure the cathode legs and soldered connections did not touch the poles or else the LEDs would short out and not


operate. Painting the poles (yellow) and the cathode legs (black) assisted in keeping them insulated from one another.

The enamel on the winding wire insulates it from the pole, but care had to be taken not to chafe the surface while pushing and pulling it through the poles - three leads through the inside diameter of a 1/16th tube is a tight fit!

The body of each LED was painted flat black but it took several "touch up" coats before no light escaped except through the front of the lens.

The fine enamelled wires were fed out the bottom of each pole to a small terminal strip where larger wires connected them, via current limiting resistors, to the outputs of the "Light Sequencer" circuit board.

This marvellous little PC board is available as a kit with all the necessary components (Cat. No. K-LS1, $A27.50) from "Talking Electronics" in Cheltenham, Victoria.
Their site: http://www.talktron.com.au (look under "Electronic kits" then, "Modelling")

Instructions on how to assemble it are published in Ken Stone's book, "Electronics for Model Railways (Book 1)" available in Dick Smith stores here in Western Australia.

Just to prove that the lights DO in fact work, here are a couple of shots showing the lights in their "red" and "green" phases.
The "Light Sequencer" PC board allows you to "program" the lights by placing diodes on a matrix board. This determines their sequence and the amount of time each phase stays on.
Once set up, just connect 12VDC and watch them "cycle" realistically.
If you look closely at these photos, you will just be able to see that while one street is facing a "red" light, the other street has "green".
The green phase turns "amber" then "red". After a momentary (realistic) pause, the other street then gets "green".

The Light Sequencer can also be used for other projects such as light chasers, shop displays and advertising signs.

Here is a peek under the box lid on which I built this intersection.

The "Light Sequencer" PC board is in the top left hand corner. Quite honestly, I don't understand how those ICs work, or how a transistor works, or how to put them all together in a circuit to make anything else work!!

I'm just good at following instructions!

The very fine wires (which you can hardly see) are the enamelled "winding" wire. I unwound the armature of a discarded N-scale locomotive motor and salvaged the wire - it came in handy for this project!

The 9 volt battery powers the diorama when not connected to a 12 volt transformer.

Mmm, now......next project - how to get those cars to MOVE when the lights turn green!

In the US, check out the light contoller available from IPE. They have a web site at:- http://www.ironpeng.com/ipe/

 

Traffic Lights in Perth, Western Australia

In Perth Western Australia, where I live, all traffic control signals are mounted on poles, painted yellow with black visors.

Here is a typical installation, in this case protecting a pedestrian crossing on Labouchere Rd, South Perth.

Note the lenses on the approach side signals are larger than those on the far side. (In Australia, traffic drives on the left hand side).

Here is a new set of signals on a recently completed section of Reid Hwy, Carine.

Note, drivers observe five lights as they approach this intersection - two large ones on the approach side and three smaller ones on the opposite side of the intersection.

The masts in the centre island and on the far right also carry right turn arrow lenses.

Very rare and unusual for Perth - a traffic signal suspended over the road.

In this case, in Lord Street, Eden Hill, the signal has been mounted high because vehicles approach the intersection over a crest in the road (behind the camera).

The absence of a mast in the centre island is also very unusual (although there IS one for the intersecting street). Note, a total of five lights facing in this direction.


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