hannah mishin

Portfolio and Blog of artist and technologist Hannah Mishin.  

Russian tri-color VFD Indicator Clock

I was drawn to the unique quality of this display.  I had just built a VFD 7 segment clock, and wanted to play around some more with Vacuum fluorescent displays.  

I am interested in making a clock - one which is not necessarily for telling THE time, but indicating the passing of time.


After doing the VFD clock, I found these Soviet new-old stock tri-color indicators on Ebay. 

The datasheet came in Russian, so I google translated the text.

I am going to use a MAX6921 20 output VFD driver chip.

https://datasheets.maximintegrated.com/en/ds/MAX6921-MAX6931.pdf

See this blog post about troubleshooting VFDs here: 

https://hannahmishin.com/blog/2015/7/18/vfd-display-clock


This display has 3 colors: Blue, Red, and Green.  There are 5 lines with 7 of each color in each line - therefore, I have 35 Blue segments, 35 Red segments, and 35 Green segments. 

I have 21 addressable pins (7 of each color).


Beginning the wiring and coding.  I tested the transistor circuitry to control the grids with some LEDs.

The Russian VFD has five lines of segments of colors.  By switching the grids on and off I can multiplex the component.

Each Grid gets a circuit which is comprised of one TIP120 - (NPN), two 10K resistors, and an IRF9510 - (MOSFET PNP).