On Wednesday, February 8, 2017 at 9:50:59 AM UTC-8, kitehman wrote: > > > so i should shoot for just under the 2.5ma current rating and go for > lowest striking voltage? higher voltage for a brighter display? >
Yes, I would aim at 2.5mA. Exact value +/- not critical. You will find, that once they strike, the maintaining voltage, is relative constant, as you change the supply voltage. They are gas filled cold cathode tubes, and just like neon bulbs, and tubes like the 0A3 and 0B2, they act as voltage regulators. Very similar to a zener diode. So if you increase the supply voltage, the neon voltage will increase ever so slightly, while most of the voltage change will be across the anode limiting resistor. Since the current is the voltage across that resistor divided by the voltage, then the current will increase, and so will the brightness. Its been suggested earlier, that you should look at pulse width modulation (pwm). to adjust brightness. That is use a fixed value for supply voltage and anode resistors, to get roughly 2.5mA per tube. But add a pass transistor to your supply so you can turn it ON and OFF at a rate faster than your eye can perceive flicker. For most people this is faster than ~30Hz. What exact frequency is not important. On the low end, visual flicker is your boundary. At the high end, its the turn ON time of nixies. It takes time for a nixie to ionize. I ran experiments on speed a tad over 10 years ago. The fastest I could get a nixie to turn ON, was a ZM1000, with its primer electrode always ON, and a 200V supply. I could get it to turn ON in 7uS. 20 to 30 is typical for most nixie tubes. 50uS nominal worse case. <https://threeneurons.files.wordpress.com/2011/08/timing01.jpg> Nixie Details <https://threeneurons.wordpress.com/nixie-power-supply/> So, in practical terms, I would set the minimum ON time for about 200uS. So if you pick a PWM frequency of 100Hz, you'll get max brightness at 10mS (0.01sec, 10000uS), and minimum at say 200uS, for a 50:1 brightness range. Your eyes don't see linearly, though, so as you view it, that 50:1, will look more like 5.6:1 (almost 6:1). -- 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/a99ee7c6-92c7-4783-86ca-a3dd1495c50a%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
