> > Then don't turn on the other tube at that time! I turn on only one tube > at a time, which removes that problem. >
That is not completely true, it's not that I turn on both tubes at the same time, it is because the current starts to flow through the wrong tube because IT CAN. With a 170V anode voltage and a 50V clamping zener, the minimum voltage on either of the tubes (on or off) is 120V. A tube that has 120V, is switched off but was switched on just a fraction earlier (due to multiplexing) will leak current from anode to ground through the zener clamping diode. You can't stop that unless you disconnect the anode from the HV power supply, through an extra transistor or something else. I agree that adding complexity will in most cases reduce the reliability. In my case, it is not so much that the circuit becomes more complex (replacing 8 transistors in 1 package by 8 discrete transistors) it is more an increase in PCB complexity. So I am not worried that it will decrease the reliability. Michel -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To post to this group, send an email to neonixie-l@googlegroups.com. To unsubscribe from this group, send email to neonixie-l+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/neonixie-l?hl=en-GB.
