Interesting. On Monday, October 30, 2023 at 2:27:50 PM UTC-4 Craig Garnett wrote:
> The directly driven tube is just 2mA and that doesn't light the pins. > If I swap the tubes then it stays with the multiplexed tube. > > On Monday, 30 October 2023 at 14:58:31 UTC Greg P wrote: > >> How much current are you using in a directly driven tube? I’ve had the >> same issue with the pins lighting up with as little as 1mA on the Z570M >> tubes. >> >> >> On Monday, October 30, 2023 at 10:31:57 AM UTC-4 Craig Garnett wrote: >> >>> Increasing the HT gave me 10mA and looks pretty good but is this an >>> issue in the photo? >>> It only occurs in the multiplexed tube. >>> >>> Thanks >>> Craig >>> >>> On Friday, 27 October 2023 at 18:13:19 UTC+1 Craig Garnett wrote: >>> >>>> Thanks gregebert, >>>> I'll have a play with the HT voltage and report back. >>>> >>>> Craig >>>> >>>> On Friday, 27 October 2023 at 16:33:12 UTC+1 gregebert wrote: >>>> >>>>> You can run nixie tubes at much higher voltages if you wish, it does >>>>> no harm as long as you increase the series resistor to keep the current >>>>> within spec. For example, my first nixie clock runs the B5092 tubes from >>>>> a >>>>> +340V supply, and I used a larger resistor (75K I think) to get the >>>>> optimal >>>>> 2.2mA current. Running at higher voltage gives you more design margin, >>>>> but >>>>> it does waste more energy as heat. Generally my HV supplies run between >>>>> +200 and +220VDC; seems like every clock I make ends-up with a different >>>>> power supply design. So far, I've designed and built nixie clocks with >>>>> B5092, B6091, B7971, IN-18, and RZ568m tubes. >>>>> >>>>> I would bump your supply up to +200V, and adjust the resistor to get >>>>> 8mA of peak current (6:1 multiplexing). That will give plenty of voltage >>>>> margin as the tubes age. From the photo, 8mA looks nice. I recommend >>>>> that >>>>> you view your tube as you vary the supply voltage to get currents between >>>>> 5mA and 12mA just so you can see the effect of current on brightness. You >>>>> should see that once the tube is lit "normally", increasing the current >>>>> doesn't make as much of a change visually. >>>>> >>>>> I dont run my tubes multiplexed for a variety of reasons. >>>>> >>>>> On Friday, October 27, 2023 at 1:38:06 AM UTC-7 Craig Garnett wrote: >>>>> >>>>>> Thanks gregebert >>>>>> >>>>>> My HT is a 12V module and is adjustable but the tube spec says 170V >>>>>> so I left it at that. >>>>>> Are you saying that it's safe to increase the HT to get maybe 10mA? >>>>>> >>>>>> Craig >>>>>> >>>>>> On Friday, 27 October 2023 at 05:06:34 UTC+1 gregebert wrote: >>>>>> >>>>>>> My concern is that over time as the tubes age your HV supply voltage >>>>>>> might be too low to ensure proper ionization. If it's not adjustable, >>>>>>> you >>>>>>> can boost it with a series DC supply such as a wall-wart transformer or >>>>>>> a >>>>>>> small isolated DCDC converter. Anything from +12 to +24 should work >>>>>>> fine, >>>>>>> and the current is pretty low (12mA). >>>>>>> >>>>>>> Once you get the HV supply resolved, you will be able to get more >>>>>>> current thru the tubes. BUT......you may want to stay with 8mA. From >>>>>>> the >>>>>>> photo, the tubes glow nicely. Tube wearout is an exponential function >>>>>>> of >>>>>>> current, so staying at the lower currents is better for longer >>>>>>> lifetime. At >>>>>>> some point, the current could be too low and you might see cathode >>>>>>> poisoning, but that's reversible. My gut feeling is that 8mA of pulsed >>>>>>> current should be fine. >>>>>>> >>>>>>> So, are you using rectified AC-mains as your DC supply ? No worries, >>>>>>> I've done that on several clocks and it can be done safely with proper >>>>>>> circuit design. >>>>>>> >>>>>>> On Thursday, October 26, 2023 at 7:28:18 AM UTC-7 Craig Garnett >>>>>>> wrote: >>>>>>> >>>>>>>> The ongoing project of mine is coming on nicely but I need some >>>>>>>> reassurance with the way I'm driving the Z570s. >>>>>>>> >>>>>>>> There are two banks of 6 multiplexed tubes, from what I see from >>>>>>>> the datasheet these should run at 2ma static or up to 12ma as a 1 in 6 >>>>>>>> multiplex but that is using google to translate from the datasheet's >>>>>>>> German. >>>>>>>> >>>>>>>> The problem is that even with a 1K anode resistor I can't quite get >>>>>>>> 8mA from a 170V supply. >>>>>>>> The photo shows two tubes, the left is static at 2mA and the right >>>>>>>> is multiplexed at just under 8mA with a 1mS on time from a 170V supply >>>>>>>> and >>>>>>>> 1K anode resistor.. >>>>>>>> >>>>>>>> Is this ok or could I do it a better way? >>>>>>>> >>>>>>>> Thanks >>>>>>>> Craig >>>>>>>> >>>>>>> -- 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/47eaafae-d445-4759-881b-020cce2dc4ben%40googlegroups.com.
