> > @gregebert - Do you have to take the fuse resistance into account in your > circuit to maintain a centered heater voltage (I guess so as the fuse > resistance can be several ohms with high speed low current fuses)? > > Eventually, yes. Right now I have safe-enough values to get the filament warm enough so that the tube should function. After I get more tubes and have the I-V data plotted for their filaments, and also confirm the brightness is correct (nominal 1850V anode supply @30uA per tube), I will fine-tune the series resistor value. The goal for me is to use somewhat less than the spec value of 200mA of filament current at the highest line-voltage I record at my house over a weeks' time, and verify that the series resistor is sufficient to view the tube during low-line-voltage periods.
So far, I have only energized the filament of my one-and-only NIMO tube once, and that was to gather IV data. I'm still tuning the HVDC inverter and have not actually fired-up the tube yet; going very, VERY slowly to make sure I dont risk any damage to the NIMO. Everything else is ready-to-go. Only after I have several days of clean operation of the HVDC supply during no-load and 150% overload will I attempt to fire the tube. I just found another bug in the FPGA that controls the inverter. It's a new design of my own, and probably way more complicated than it needs to be, but it's regulated and allows software control of the voltage, contrast, and even the tube current. -- 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/6507907e-cecf-4f88-95c6-9f7e8fc65900%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
