My clock is direct-drive, using 400V NMOS (IRF740) separate drivers on each cathode. Yeah, that's 45 drivers for 6-digits heh-heh.....did someone say "overkill" ???? DC supply is 350V (from AC-line doubler) to all anodes. I like the higher voltage so that as the ionization voltage increases with age, they will still illuminate reliably. It also reduces cathode-current variations due to tube characteristics, line-voltage, etc at the expense of higher energy usage.
But I will check the leakage current of the dark cathodes. Datasheet says less than 1ua at 25C (<50uA at 125C but I'm nowhere near that temperature....). When my cathodes are off, they essentially float (off-impedance of NMOS). I thought about tying them thru a big resistor to the HV supply, but I reasoned that the leakage current was negligibly low so there should not be any glow. With regard to the green glow tube, it's definitely the tube, and not the driver, because when I rotate the tubes for uniform usage, it's the same tube with the green glow even though it's being driven from a different driver than previously. -- 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/5274bcf3-c95a-444d-a029-fc13a9999271%40googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
