niXmos linear nixie tube controller

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niXmos linear nixie tube controller

Post by infiniteimprobability »

Version: 1
Status: Beta
License: BSD
Download: /files/project_builds/

For those of us who like retro display technology..
A linear nixie bargraph tube driver:

Linear bargraph nixie tubes - 2 channels initially
PWM controlled programmable current source (via big ass high voltage NPN transistor)
Xcore controlled voltage stabilised DC-DC boost converter (set to 140V using a PI controller). Can supply 35mA+ so a bit bitey if you are not careful
Input source for bargraph display could be: temperature, time (linear clock) or (my favourite) audio signals. Ie. Retro VU meter
Hardware will consist of a startKIT and some bolt on hardware made on proto board.. 

Currently running in ramp (test mode)..
Uses around an amp at 5v full scale - these tubes don't half take some driving (15mA * 100V = 1.5W * 2 + losses)
Here's some useful info on the IN-9 tubes used 
Also developed and included is a PWM routine that allows 4 x 10b PWM at 20KHz in a single logical core (or more channels at lower resolution or frame frequency). It uses the serialisers to generate the edges and so can reach all steps from 0 to 100% duty cycle. It uses a duty cycle buffer so that the new duty is transferred at the end of the PWM frame.