> First question is the filament. The active display area is around 4" x > 3.5", with multiple parallel filament wires running down the long > axis. I don't want to over-drive the filament and burn out the > display.
Set it up in a darkish place with a variable voltage power supply, or a few volts with a variable series resistance (a hundred ohms or so should do). Bring up the voltage or lower the resistance until the filament is a barely visible red. Sometimes it's easier to bring it up to a dull orange, then back down until it just disappears. This should be close for most VFDs, you can fine tune it when its lit if there seems to be insufficient emission. > Also, am I going to have a brightness gradient across the > display if I drive the filament with DC? There might be some, depending on the voltage you're using. If you're multiplexing with a 60-volt supply, the filament difference will be proportionately small and shouldn't be visible. If you're using a 24 volt supply, it might well be visible. One route I use is a small center-tapped transformer and series resistors to get the filament voltage down to where I want it. This can be either an ordinary mains voltage filament transformer, or the small high-frequency transformers that often come with VFD power supplies (I buy cheap ones from surplus outfits and then adapt them to whatever VFD I'm powering). > Each of the actual elements that lights up is typically quite small - > there's probably 70 or more individual elements in there. Most are the > normal blue-green VFD color, though there are some pure green ones and > even a few red ones. That's neat! Is it words and symbols, or just an array of segments or what? - John -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To post to this group, send an email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/neonixie-l?hl=en-GB.
