Anyone with even a passing familiarity with the classic animated shorts of the 1940s will recognize the traffic signal in the image above. Yes, such things actually existed in the real world, not just in the Looney world of [Bugs Bunny] et al. As sturdy as such devices were, they don’t last forever, though, which is why a restoration of this classic Acme traffic signal was necessary for a California museum. Yes, that Acme.
When you see a traffic signal from the early days of the automotive age like this one, it becomes quickly apparent how good the modern equivalent has become. Back in the day, with a mix of lights distributed all over the body of the signal, arms that extend out, and bells that ring when the state changes, it’s easy to see how things could get out of hand at an intersection. That complexity made the restoration project by [am1034481] and colleagues at the Southern California Traffic Museum all the more difficult. Each signal has three lights, a motor for the flag, and an annunciator bell, each requiring a relay. What’s more, the motor needs to run in both directions, so a reversing relay is needed, and the arm has a mechanism to keep it in position when motor power is removed, which needs yet another relay. With two signals, everything was doubled, so the new controller used a 16-channel relay board and a Raspberry Pi to run through various demos. To keep induced currents from wreaking havoc, zero-crossing solid state relays were used on the big AC motors and coils in the signal. It looks like a lot of work, but the end results are worth it.
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8-6-2021 (August 6, 2021) is the Snakiest day of the year and it’s also this year’s CircuitPython Day! The day highlights all things CircuitPython and Python on Hardware. See you there!
Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, TinyGO, or even use the Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for CircuitPython, MakeCode, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.