I didn't purchase any numitrons yet, however my tests with a CCS and a small 15V 30mA bulb show that with current limit of 20mA, the filament turns on with a fade in effect, which takes about 200ms, in this case. I enjoy it, so I hope I'll be able to reproduce it with numitrons, as it would both help their life and add a nice effect. With 30mA the turn on time drops to under 100ms, and with brightness of this bulb is hardly noticable.
I think the inrush current is needed for bigger filaments and/or faster switching - small bulbs (and, I hope, numitrons) have short pieces of wire with low thermal capacity. gregebert, thanks alot for the link to the paper. I've read it, definitely learned alot from it. I was prepared to lower the current of segments to help them live longer, and with a LED current sink this will be very easy. If only producers told how the resistor is sensed by the chip, so I could replace it with a transistor and a DAC/lowpass filtered PWM... That's why I didn't want to use limiting resistor and higher voltage. On second thought, maybe a regulated boost converter would do the job - I could dim the clock by changing whole tube power supply voltage. W dniu środa, 21 lutego 2018 16:43:27 UTC+1 użytkownik nixiebunny napisał: > > The inrush current performs the important job of heating up the filament > so that it will glow. Don't expect an LED driver to work well. Experiment > with some low ohmage series resistors first. > > > On Feb 21, 2018 6:39 AM, "Terry Kennedy" <terry-...@glaver.org > <javascript:>> wrote: > >> On Wednesday, February 21, 2018 at 8:26:39 AM UTC-5, Tomasz Kowalczyk >> wrote: >> >>> What are your experiences with numitrons? What methods of prolonging >>> their life did you use? Or did you just ignore the problem, as IV-9 and >>> IV-16s are still quite cheap? >>> Please share your experiences and thoughts. >>> >> >> I have a pair of Numimini clocks (from Jon Ellis here) with IV-9 tubes >> which have been running continously here for over 8 years with no issues. >> They are powered by the host PCs' USB ports, so there is some magic >> involved in staying under the available 500mA available when driving the >> filaments. >> >> -- >> 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+...@googlegroups.com <javascript:>. >> To post to this group, send email to neoni...@googlegroups.com >> <javascript:>. >> To view this discussion on the web, visit >> https://groups.google.com/d/msgid/neonixie-l/cffdaf54-d5c8-44c7-826e-36cffee300ca%40googlegroups.com >> >> <https://groups.google.com/d/msgid/neonixie-l/cffdaf54-d5c8-44c7-826e-36cffee300ca%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> For more options, visit https://groups.google.com/d/optout. >> > -- 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/5f2c928c-463b-4826-a278-ed285a22cbdc%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
