nixie-clock-hardware

Hardware for controlling six Nixie IN-14 tubes as clock (HH:MM:SS)

Requirements for rev 1.0

• efficient step-boost converter up to 190V
• multiplexing
• control syncronous addressable LEDs
• PWM control
• I²C interface
• connector for ESP (UART)
• time syncronisation line for every second

Known issues in rev 1.0

• octal buffer for PWM use seems do not works for dimming
  • workaround: dimming solved by adding turn-off points in mulitplexing routine (firmware-based solution)
• bad mosfet selection -> high R_DSOn lead to heat at high current due diode reverse current shots
  • workaround: use better Mosfet with TDSON-8 footprint that can be soldered onto the existing one
  • caution: soldering TDSON-8 with thermal pad on back causes short circuit due to untented via underneath pad
• output cap is to small -> causes high voltage ripple
  • workaround:
    • add 2.2uF with 2220 footprint
    • add 180uF electrolytic cap
• ESD protection on ARGB connector has wrong wiring
  • workaround: do not use USBLC6 and add enameled copper wires

Renderings (rev 1.0)