Thanks for the information, they are very helpful. :) Christian Riise Wagner 在 2023年1月15日 星期日下午5:45:03 [UTC+8] 的信中寫道：
> The voltage across the tube starts high, while the tube impedance is high, > before the gas discharge has been established. The current then rises > relatively slowly, while the voltage drops at a proportional rate due to > the anode resistor. Threeneuron has an excellent page on driving nixies > <https://threeneurons.wordpress.com/nixie-power-supply/>, which also has > a scope capture of a Nixie striking. The lack of surge current should mean > that there won't be additional power dissipation and thus heating during > this period. Also, because the current doesn't rise that fast, that should > limit the high frequency components of EMI emissions. > > In regards to audible noise, I think this depends on the physical > construction of the tubes in use. I don't have a large sample size in this > regards, as I have only implemented dimming and cross-fading on my Z566M > clocks and haven't noticed audible noise from that. I'm running it at 400Hz > IIRC. > > I guess a valid point could be that if the tubes are generating audible > noise, that could mean that there are some physical stresses being being > exerted, which could cause wear. The glass to metal joints are the weakest > spots. This is pure speculation though, and I think there are multiplexed > clocks out there that have been running for a couple of decades on end by > now. > søndag den 15. januar 2023 kl. 04.03.19 UTC+1 skrev overdoingism Lab.: > >> For the following reasons: >> >> 1. High voltage swing PWM, I am afraid it will cause EMI interference. >> >> 2. As far as I know, the impedance has a sharp change during the lighting >> moment. (As arc discharge?) >> PWM driving may mean more heat generation, more aging and wear? I'm not >> sure. >> >> 3. If you want to completely avoid audible noise, the PWM frequency >> should be raised above 30khz. (Not only tube, also coil.) >> Considering that is voltage >150v , the stray capacitance effect will >> become significant, and there may be reliability and safety hazards. >> And also, I'm not sure Nixie tubes are responsive enough. >> >> About these reasons. (I'm not sure if my concerns are correct.) >> >> Christian Riise Wagner 在 2023年1月15日 星期日凌晨12:53:18 [UTC+8] 的信中寫道： >> >>> Out of curiosity, why doesn't PWM sound like a good idea? There isn't >>> really an alternative, other than lowering the current, which you don't >>> seem too fond of either. I'd say PWM is the easier method. Just choose a >>> sufficiently high frequency to avoid noticeable flickering. Note that the >>> ammeter averages out readings, so whether the tube is driven at a constant >>> reduced current or PWM, the reading will be lower, even though PWM is full >>> current delivered in pulses. >>> lørdag den 14. januar 2023 kl. 14.14.52 UTC+1 skrev overdoingism Lab.: >>> >>>> My nixie clock has a switch, with three level, full - low - off. >>>> >>>> The low level setting does make the tube look a bit dimmer. >>>> >>>> And the current seems to be slightly below specification. >>>> >>>> For all I know, it's probably not good for "Cathode Poison", but I can >>>> switch back to full level to flush them. >>>> >>>> Besides, is there any disadvantage? >>>> >>>> BTW, Is there any way to adjust the brightness? PWM doesn't seem like a >>>> good idea. >>>> >>> -- 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 view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/954a7da8-58e4-43b6-ae3e-5e434bdc796cn%40googlegroups.com.
