Atomic Clock Using Nixie Tubes

This Atomic Nixie Clock came from the concept of building a simple Nixie clock but it turned out that a WWVB receiver and decoder chip were also employed.

Transmitting at a very low frequency of 60kHz, the WWVB was the call sign of the atomic clock in Colorado. A sensitive receiver is required to pick up the signal that can travel far and be decoded. A 321B receiver/decoder was used since it has its own accurate clock which keeps track of time during periods of poor reception.

A PIC12F675 microcontroller queries the 321B for the time once the WWVB signal has been received and decoded. The data will then be passed to a 433MHz transmitter. The clock is run by a Basic Stamp which queries the receiver for data and passes the time to the shift registers.

At least 10 pins are available in the Nixie tubes where one for each digit and the cathode as it requires fairly high voltages, around 170VDC, to operate. To operate them, specialized chips are required such as the SN74141N.Iit reduces the number of inputs required for each Nixie to four while handling switching the high voltage.

Rest of the project