> Thanks for the reply. I put the -25v on pins 1 and 11 (cathodes) and GND on > pin 2(grid) and GND on a random anode to see if it would light up and nothing > illuminated.
The filament needs to be hot to emit electrons for the VFD to operate - this is normally accomplished by heating it electrically. I did kind of gloss over this -- you have to have voltage across the filament as well - this is true no matter how the other voltages are supplied. The "ideal" method is to have a small center-tapped transformer providing the AC filament voltage (generally something between half a volt to a few volts), and hook the -25V to the center tap. I often use a generic 6.3V filament transformer, with series resistors to drop the voltage to whatever the VFD filament needs. Some people don't want to bother with an AC filament voltage, and just run it with DC - this will work, but can lead to brightness gradients in some tubes. So, just to light something, at a minimum, you'll need -25 volts at one end of the filament, -(25 + filament voltage) at the other end of the filament, and 0V at the grid(s) and anode(s) you want to light. - John -- 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/C81F0687-BB98-4FAD-A200-745055041C3E%40mac.com. For more options, visit https://groups.google.com/groups/opt_out.
