The first made appearance in 1967 in Japan in desk calculators, perhaps to avoid paying royalty to Burroughs for Nixies. The Russian IV-15 is often offered as an equivalent of the European DM160 but it’s actually different shape, size and characteristics, though similar. Thus the DM160 and IV-15 are like Triode, Vacuum equivalents to LEDs or lamps rather than “Bargraphs” or “Magic Eyes. All the other types of VFD use On/Off segment and/or digit/character drive rather than continious voltage. Unlike the Magic Eyes the DM160 and IV-15 do not vary in size, but brightness as the grid is varied. The larger multiplexed displays need AC drive on centre tapped feed or else one end of the display is brighter. Thus multiplexed display the “ grid” switches large areas and the “ anode” sub sections under it. The Grid is driven to full HT to turn “on” the underlying segments, which are usually Anodes. Unlike the “Magic Eye” the HT is only 12V to 30V, and the grid just below the direct filament cathode to turn a character off. Unlike other vacuum devices (Valves aka Tubes or CRT) these are still popular in mass produced consumer equipment such as DVD, Blu-Ray players, HiFi and “Set-boxes”. These are miniature low voltage triodes with the anode coated in phosphor rather than a separate target electrode to the Anode as on “Magic Eyes”.
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