If you’ve ever utilized an old tube radio, you may be familiar keeping that mysterious bit eco-friendly screen that assists you to tune precisely to a station. That screen is called a tuning indicator, or magic eye tube; in essence it’s a minimalistic cathode ray tube that can sweep its electron beam along only one axis. It thereby outputs a type of bar graph that varies with the input voltage.
With few contemporary utilizes other than being pretty, it only makes sense that these tubes discover their method into works of art: [Patrice] utilized one to make an insect-like piece of circuit sculpture. The tube he utilized is an EM34, which is one of the most typical sign tubes around as well as has a circular, iris-like screen area. This becomes a big eye, peering ahead from the bug’s body. The legs are made of 1.5 mm thick brass wire, while a DC/DC converter produces the 210 Volts DC needed to operate the tube.
An fascinating “touch” is the addition of two antennae that are hooked up in such a method that the tube’s picture modifications when you push them; this interactivity makes the bug come to life a bit bit. speaking of touch, we believe it would be prudent to put some insulation around the 210 V wires; even though the bug is battery-powered, touching the high voltage as well as ground wires concurrently would provide a nasty shock.
Nevertheless, the bare-wire vintage style looks lovely as well as would make a excellent ornament for any type of electronics-lover’s office. We’ve seen magic eye tubes being utilized for different purposes: you can turn them into a spectrum analyzer, determine capacitors with them, or just utilize them as a bar-graph display.