Background
Nixie tubes are outdated numeric display devices than were very popular back in the 1950's until the 1990's, until newer and more efficient technologies like the light emitting diode and vacuum fluorescent display came into play.
They are cold cathode devices meaning they don't operate at high temperatures and don't have a heating element like many other similar devices such as vacuum tubes.
The construction of this device includes a wire-mesh as the anode and multiple cathodes in the form of numerals which light up with a glow discharge when a sufficiently high voltage is applied on the anode, ionizing the gas.
Nixies are low-pressure tubes filled mostly with neon mixed in with some Mercury or argon in a Penning mixture to reduce the firing voltage required for the tubes and therefore increase efficiency.
I have always been intrigued by antique technology, specially when its used in conjunction with newer technologies that give it new life. Working with older technologies also gives me a new found appreciation for the technologies that we have today and the advantages or disadvantages of the different technologies.
I chose to do a nixie tube clock for my project because of several reasons: I thought they were very cool, I had never worked with high voltage or with many of the components I was going to use for this project so I figured it would prove to be a nice challenge, and my sister was getting married in the summer so I needed to get a present for her.