On Tuesday, January 22, 2019 at 9:05:31 PM UTC, gregebert wrote: > > The advantage and importance of the series anode resistor is that it makes > your anode current more predictable. Without the resistor, your anode > current will be determined primarily by the tube's characteristics, which > vary over time and tube-to-tube, ie unpredictable. >
And that's important in a multiple tube display (which after all is the motivation to entertain the design idea of multiplexing), because you don't want different currents and therefore potentially visibly different glow intensities across the array. Quicker/more reproducible ignition is also important in the multiplexed setting also because variations in the actual duration of glow during the multiplex time slice are going to be perceived as intensity differences too. I can't explain exactly what's happening in your current experiments, but suggest that you follow the theoretical & datasheet advice: 190V and a calculated anode resistor that puts the anticipated current in the indicated range. And then adjust the anode resistor experimentally to give you acceptable brightness when driven in the multiplex setting. You may be surprised by how little additional current is needed above the direct drive steady illumination range to generate a perfectly acceptable brightness while multiplexing. That depends of course on the multiplexing ratio that you are looking to use: a 1 x 6 multiplex is going to need to need the peak current pushed harder than using the same 6 tubes in a 2 x 3 multiplex (which was my preferred arrangement on my IN12 42 tube clock). Jon. -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send an email to [email protected]. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/9a395b14-f562-4a3a-bb9d-fab42807a9b1%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
