Walk, Don’t Walk!

A few weeks back I received an old pedestrian sign, the kind that shows an image of a person walking in white LEDs or a large hand held up to indicate “Stop!” in red LEDs. My cousin had recently purchased a batch of these at an auction for dirt cheap and thought that I might want to bring one to life again. What a gift!

With the help of my brother, a journeyman electrician, we planned out what materials were needed. The simplest route to getting this sign to work again is to supply power through a switch. I needed the kind of switch that allows the light to be turned off, turned on (hand) or turned on (walker). An SPDT switch made the most sense, a single pole with two throws, rated for at least 120W, available on Amazon.

IMG_8194
Single Pole Double Throw Switch

We needed wire and plug to connect to the wall outlet, so I purchased an inexpensive extension cord and cut off the socket end to wire the separate leads into our switch and terminal block. 

Here are the wiring connections, using the switch to control which signal (hand or man) would receive the power. 

Traffic Sign wiring
The switch determines where to send power, to the Hand, the Man, or neither (OFF).

Care must be taken to identify which line is hot and which is neutral or ground in the extension cord. Here is an article to help determine which wire is which.

Finally, we needed a secure way for the wires to enter the box. A cord gripper can be used to keep the cables from slipping in and out. While I wasn’t able to acquire a cord gripper in a timely manner, Home Depot had a stress reliever, which functions in a similar way, keeping the cord tight so that it won’t get pulled out and disconnect the wiring.

IMG_8253

Once the electrical concepts are understood, the wiring was pretty straightforward.  Here’s a short video just before all components were in place, as I test the wiring and the switch.

After testing the connections, I drilled one hole in the side of the light box as a permanent location for the switch, and another for the stress reliever and wiring that will plug into the wall.

What’s Next?
With a simple ON-OFF-ON configuration now working, I’d like to explore the use of an arduino or other microcontroller to program a sequence of blinking and solid lights and the addition of a sensor or other trigger to activate the light. This would give a more realistic effect and follow more closely to how these lights work in the real world.

Here is an example of one YouTuber that integrated an arduino and some relays into his project.

I have no idea where this one will end up. Maybe in the classroom or maybe in my daughters’ bedroom. I’ve enjoyed learning a bit more about high voltage electrical and look forward to expanding this project in the future.

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