Simulate a retro-tech look without the fuss Photo: Randi Klett
Stanley Kubricks 1968 science fiction film 2001: A Space Odyssey still stands up pretty well. But theres a telling anachronism in the scene where scientists visit a monolith thats been uncovered on the moon. On their lunar shuttles control panel, there are numerical indicator lights clearly made with cold-cathode displays, also known as Nixie tubes. This technology was in vogue during the mid-1950s but fell out of favor in the 1970s.
Nixie tubes still enjoy a following among enthusiasts of retro technology. Ive sometimes been tempted to build a Nixie-tube clock, but the difficulties and expense always put me off. Its hard even to purchase Nixie tubes at this pointespecially larger onesand they require high-voltage driver circuits, which are inherently dangerous. So I was delighted when I stumbled on something designed to mimic the appearance of Nixie tubes without the complicationssomething its designer calls a Lixie display.
Lixies contain WS2812B smart LEDs at one end, which can change colors on demand. The light from the LEDs is funneled into a stack of acrylic sheets. Such edge-lit displays use a phenomenon called total internal reflection, which keeps the light inside the acrylic except where it has been etched. (This form of display has become popular for exit signs, for example.) Each sheet is laser etched with one numeral, and typically only one sheet is illuminated at a time.Photos: Randi Klett
Not a Nixie: Construction of a clock requires a base for mounting four or six Lixie displays [top]. A different digit is etched in each of the 10 acrylic planes contained in one display [middle]. LEDs at the bottom of the display project light into one acrylic plane at a time, which then glows where it has been etched. Reflections in the other planes...