Geometric Nixie tube clock and environmental display
May 21st, 2019—
Creators keep coming up with new clock designs, and while you might think that every new possibility has been exhausted, Christine Thompson has proved this assumption wrong once again with her “VFD Trilateral Clock.“
This Arduino Uno-powered device employs a stepper motor to rotate a triangular prism shape with scales for hours and minutes on one side, temperature in Celsius and Fahrenheit on the other, and humidity and pressure on the third surface.
The geometric scale travels in 120-degree steps, causing each face to line up with a pair of IN-13 Nixie tubes on either side. These linear tubes are then used to indicate time and environmental conditions in a beautiful bell jar display, as seen at around 3:30 in the video below.
While waiting for the delivery of parts for another project I decided to push ahead with this project. At its heart is two IN-13M Nixie tubes. These tubes are designed to provide a linear scale between maximum and minimum points using an illuminated column. The project uses two of these IN-13M, three wire Nixie tubes to show, time (Hours and Minutes), temperature (Celsius and Fahrenheit), Humidity (percentage), and Pressure (millibars).
At this point I would like to thank Dr. Scott M. Baker for his great web site, which provided me with all the information I needed to get these Nixie tubes to work. In particular the Current Regulator as displayed and detailed on his web site.
The project uses a BME280 sensor to determine the temperature, pressure and humidity and RTC clock to monitor time. As the system needs to display six different values it was necessary to construct a rotating central display which showed these values against six scales. In order to achieve this an equilateral triangle of wood was fashioned, each side showing two sets of values. A stepper motor was mounted under the top platform and this motor rotates through 120 degrees in time for the next set of values to be displayed on the two Nixie tubes.