On Friday, February 12, 2016 at 7:48:07 AM UTC-8, jrehwin wrote: > > > I'm not surprised. Just a few hundred microamps is enough for visible > glow, and those transistors can have current gain in the hundreds. Most > flux is hygroscopic, so it pulls > moisture out of the air, and then the residual salts make it conductive. > > - John >
To make matters worse, it most likely was caused on the anode driver side. Each driver has two transistors. They are HV transistors (MPSA42 & MPSA92), so their current gain can be as low as 25, but usually twice to 4 times that. Even at the lowest values, to get 5mA into the nixie anode, it only takes 8uA to into the base of the low side transistor. Usually, you don't think about this kind of leakage with digital circuits. Doing something, slick and fancy, never goes unpunished ! -- 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 neonixie-l+unsubscr...@googlegroups.com. To post to this group, send an email to neonixie-l@googlegroups.com. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/547013bd-38db-4804-b328-acb28017197e%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
