Nixie tube

Nixie tube ZM1210 (without dip coating) with ten digits and decimal point, side view.
Diameter 19 mm, digit height 15 mm

A Nixie tube is an electronic component for displaying characters based on the glow lamp principle .

construction

The characters to be displayed, usually the digits from 0 to 9 with a decimal point or comma, but also other characters depending on the application, are punched out of fine sheet metal or bent from wire one behind the other and electrically isolated from each other as cathodes in a noble gas (often neon - for orange-red luminous color) filled tube. All around in front of this number package is an anode, usually designed as a fine metal grid, in the tube and at the very back a black background. When a voltage is applied (depending on the type about 80 to 250 volts DC ) between the anode and one of the cathodes, the gas glows in a thin layer around the corresponding symbol.

Different colors can be achieved with different inert gas mixtures. The height of the digits ranges from 8 to over 120 millimeters. Due to the need to install all cathodes spatially separated from one another in the tube, the number of possible characters per tube is limited to about twelve.

history

The principle of the Nixie tube has been known since the 1920s, but was little used until the advent of digital signal processing in the 1950s. "Nixie" was in the United States in 1954 by the Burroughs Corporation as a trademark registered and is short for " N umeric I ndicator e X perimental No. 1 ”, the name of a first draft of such a tube.

As a result, several established manufacturers of electron tubes such as Valvo , Telefunken and WF started producing Nixie tubes. The British manufacturer Ericsson LTD. used the brand name "Digitron" for legal reasons .

For a short time, multi-digit tubes with 8 to 14 sets of digits arranged next to one another came into circulation under the name Pandicon .

In the 1960s and 1970s, Nixie tubes were mainly used in measuring devices and electronic calculating machines . Later, with the advent of vacuum fluorescent , light-emitting diode displays ( seven-segment displays ) and finally energy-saving LCDs, they quickly lost their importance.

Due to their special appearance, Nixie tubes have become popular again, so they are preferred by hobbyists to build clocks. The tube production was stopped a long time ago, which is reflected in the prices, especially with the large formats. Recently there have been attempts to produce Nixie tubes in small series again. Probably the most successful is the programmer Dalibor Farný from the Czech Republic, whose experiments began in February 2012 and led to the first market-ready Nixie tubes towards the end of 2014.

The designation of the Nixie tubes almost always begins with ZM and a 4-digit number. Examples: ZM1000, ZM1020, ZM1040, ZM1080, ZM1082, ZM1210, ZM1212, ZM1080, ZM1032. Other names were: CD66A, Z566M, IN 8-2, NL-5441.

ZM1082 in action
Arrangement of the cathode sheets one behind the other in a nixie ИН-19В / IN-19C with the anode grid removed
Individual cathode sheets of a Nixie ИН-19В / IN-19C for the characters π A / B ~ <-> + dB
Comparison of displays
Above: Nixie tubes
Middle: LEDs ( 7 Seg. )
Below: VFD
Nixie tube, ca.1970; Diameter 30 mm, digit height 18 mm
Modern Nixie clock from a hobbyist, here with LED backlighting
Systron-Donner frequency counter from 1973 with Nixie tube display