In laymen’s term, nixie tubes are those really cool glowing lamps that is used in clocks, calculators or countdown timers. You might have seen them on photography websites owing to their alluring near magical looks and flashy colours.
If you’re a tech-geek who’s looking to enter the world of hardware from software, you might need a different definition. So we’re here to give you all the essentials on what they are and how they work. If it stokes your interest, check out how to build a nixie clock to build your very own nixie tube clock under a budget!
What are Nixie Tubes?
A nixie tube is an electronic device that is made up of a glass tube containing a wire mesh anode and multiple cathodes shaped like the symbols it needs to portray. It displays the information by using glow discharge, which is a plasma formed when electricity is passed through a gas. Conventionally, nixie tubes display the numbers 0 through 9, which can be formed by the stack of bent wires, arranged inside a sealed glass bulb. Applying power to one of these cathodes causes a glow discharge. We also have other designs that show letters, signs or symbols.
The reason for their old-world look when glowing is that the symbols are all stacked one behind the other and hence exists at a different depth. This does not mean that they are arranged in numerical sequence, the advantage of this arrangement is that it is a topographic design, increasing legibility and visibility of the cathode currently in use.
Nixie tubes were used in digital voltmeters, multimeters, frequency counters, and other such equipment in the early days, some other areas of application include digital time displays for both scientific and military research facilities, first models of both electronic desktop calculators and electronic telephone switchboards.
How Do Nixie Tubes Work?
Now we know that the nixie tubes display information by glow discharge. So how do they work within this design? Well, we know that all the bent wires that represent a set of information are kept within a sealed glass bulb. The glass bulb encapsulates a mixture of gases like neon, mercury, and argon. A metallic is places at the end of the glass bulb, which can be connected to a power supply. When voltage is applied to this, is causes electron movement and at a particular voltage, a phenomenon known as Townsend Avalanche is reached which causes an exponential increase of charged particles and hence accelerated increase of current. At this voltage the tube is ignited, causing the bent wires to glow. This is how the information is displayed within the tube.
The arrangement of the cathodes along with the distance between the cathode and the place of origin of glow owes to the distinct glow of a nixie tube. The cathode that glows in a nixie tube isn’t actually hot since the glow is not produced from heat, like in incandescent bulb. As a matter of fact, the cathodes are cold, hence the process is called Cold Cathode Glow Discharge.
Now that you know what Nixie tubes are and how they work and why they have such a distinct glow, we hope you’re fascinated with these amazing piece of technology!