> Do any of you use some sort of protection circuit for the filaments? I just use a higher voltage supply and a series resistor. That way, the difference in current between a cold filament and a hot one is less, so the starting surge is minimized. It's less efficient than just driving the filaments at their rated voltage directly, but safer. Another approach is to use a current regulated supply instead of a voltage regulated supply - then you can skip the resistor.
Note that if you're using a 7806 anyway, the efficiency is the same - it's a linear regulator, so the heat shows up in the regulator instead of the resistor. In this case, I'd either use a 7808 and a resistor (reducing the heat on the regulator and gaining some protection), or wiring it up as a current source: http://www.circuitstoday.com/fixed-positive-voltage-regulators As it happens, the 7806 does have the ability to limit current, so it won't give the cold filament more than 1.5A or so anyway, which helps a little (it's still more than 3x the rated current, however). - 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/0FDAF270-5B0B-430C-B67A-B4C409EF7DE8%40mac.com. For more options, visit https://groups.google.com/groups/opt_out.
