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Nixie Clock


I designed and built this basic 4 tube nixie clock in my senior year of high school.

For more a detailed introduction, please read the Nixie Clock: History page.

Essential Specifications

  • Display
    • 4x ИН-16 (IN-16) Nixie tubes
    • 208V anode bias
    • 1x К155ИД1 (K155ID1) high voltage BCD to decimal decoder/nixie tube driver (74141 equivalent)
  • Processor
    • Microchip PIC18F2550-I/SO
    • 32K Flash
    • 2K RAM
    • 10x 10-bit ADC
    • I²C, SPI, and EUSART peripherals
  • Clock
    • Maxim/Dallas DS1340C
    • I²C Interface
    • Built-in crystal
    • Backup battery support
  • Power Supply
    • Input: 12V DC
    • Output: 5V DC
    • 7805 regulator
  • High Voltage Power Supply
    • Input: 12V DC
    • Output: 12V - 300V DC variable
    • Boost topology
    • IRF720 MOSFET switch
    • MUR120 diode switch
    • 4.7µF Inductor

Detailed Information