Oh boy, I have to build me one of these!

Ever since I looked into vacuum tubes for my brief history of the IC chip I’ve been lusting after this clock. It’s made using nixie tubes, close cousins to the vacuum tubes that eventually led to the invention of the transistor and the development of the IC. Nixie tubes are the forerunners to LED displays, it’s basically a glass tube with a wire mesh anode and lots of cathodes, mainly shaped as numbers but you can get letter and symbol ones, you can see these in the broken tube below: 

The tube is filled with a gas mixture like a regular lights bulb. When you power one of the cathodes (about 170volts worth) it makes it glow this beautiful soft orange colour. The main difference between vacuum tubes and nixie tubes is that the nixie tube is classed as a cold cathode tube, it rarly gets hotter than 40 °C where as vacuum tubes relied on (and here’s a cool technical term for you…) thermionic emissionof electrons from a heated cathode to work (really not gong to try and explain this one…).

Nixies were used to provide numeric displaysfor loads of early digital voltmeters, calculators and multimeters. They were also used in time displays for industry and military, even some lifts used them to display floor numbers. They were replaced by LEDs as these new comers were much smaller and stronger and required much lower voltages to work allowing them to be used with IC chips.

All is not lost however, nixies have such a cool aesthetic (being kind of retro in an obsolete tech kind of way) tons of people are buying all these unused tubes that have been sitting around for years and making them into amazing gorgeous digital clocks, date displays and even wrist watches!

I’ve found a couple of net tutorials so you never know… I might be posting my own clock at some point