When driver ICs were relatively expensive, it may have made sense to share
across tubes by pulsing the filament (cathode) bias as shown in the
datasheet. Theoretically, you can compensate for differences in tube
brightness by adjusting the bias uniquely for each tube. I dont know if you
need
The datasheet IEE_Nimo_808.PDF that can be found on the internet mentions
"Time sharing" (multiplexing) and I have just glanced at it to see if it
would make the circuit simpler.
Is the brightness difference a problem?
Is it possible to compensate for it by using a filter or by using a series
Direct-drive. I never considered multiplexing them, though it might be
possible due to phosphor persistence.
Now that I've powered-up 4 tubes and gathered more data, I'm seeing
tube-to-tube differences in brightness which is not only visible, but also
measurable via anode current. That could
Does your design run them multiplexed or direct drive?
/Martin
On Saturday, 24 September 2022 at 08:28:31 UTC+2 gregebert wrote:
> It's not a dollars-and-cents answer. I've spent hundreds of hours, and a
> fair amount of money on the research, design, debug and development to get
> this very
It's not a dollars-and-cents answer. I've spent hundreds of hours, and a
fair amount of money on the research, design, debug and development to get
this very complex design working. At a future date, there will be a limited
number of tubes made available for sale by the co-sponsor of this
