A couple of points. You are going to need more than 0.2-0.3 mA to fully light a nixie tube. Otherwise, you will see gaps in the numerals.
A camera flash power supply has DREADFUL efficiency, is usually designed to work from a 1.5V battery, and does so by pulling HUGE currents - often over 1 amp. Here are the reasons why. Assume you need a 200V power supply, and at about 6 mA. That's 1.2W out. The simple circuit found in cameras will be no better than 50% efficient, so that's at least 2W in. Even with a fully charged battery, that's 2/1.5 OVER ONE AMP in!! so you've got to build a power supply capable of delivering over an amp, at one and a half volts, just to pamper to your camera circuit. Why bother? John points out several alternatives; I would further add that I have seen small custom-built power supply modules on eBay that will run from a much more convenient 12V or thereabouts, and return much better efficiencies. If you are wary of building your own, then certainly look at one of these: http://www.ebay.co.uk/itm/NIXIE-TUBE-POWER-SUPPLY-MODULE-CLOCK-2-OUTPUTS-/250871015688?pt=UK_Consumer_VintageAudio_RL&hash=item3a6913e908 ALSO! A camera flash power supply will be designed to charge a much larger capacitor (for the flash) than these custom supplies like the ones above, and this is capable of giving you a much bigger BELT when you put yourself across that open circuit 330V, than a smaller, current limited 180V supply. And, no matter how careful you are, sooner or later you will do this! Alas, I know this... :( Laurence (AKA MrNixie, UK) On Oct 9, 3:08 am, John Rehwinkel <jreh...@mac.com> wrote: > > I've just got my IN-14 tubes and started experimenting on my first > > nixie project - the clock, of course! For now I am using a disposable > > camera as my power supply. Shorted out with an amp meter, it gives a > > steady 12.8mA at 330V, which is better than expected. > > More accurately, it pushes 12.8mA through a short at zero volts. I'm guessing > the 330V is no load. So in-between, you're getting less than 330 volts at > less > than 12.8mA. > > > So my question is; should I continue bothering with this power supply > > (should it even be used for 6 tubes) and try to fix my schematics, or > > just make my own power supply which I am not so fond of. > > I'm guessing the camera supply just isn't up to the job, sad to say, but > likely. > > So there are a few ways you could proceed. If there are more where that > came from, you could use six camera supplies, one for each tube. That > might work, and would be amusing. Otherwise, you'd have to come up > with the voltage some other way. The easiest way is probably to buy a > ready-made supply like the Tayloredge ones. They're small, reliable, and > very cost effective at $13 apiece, and you don't have to make your own. > > Alternatively, if you're using an AC supply, you can use a transformer in > reverse to step-up the voltage, and rectify that. Three parts (transformer, > diode, and capacitor) and you're there (you can steal the capacitor and > probably the diode from the camera supply). > > > Can driving nixies at such low voltage and current damage my nixies? > > Yes, running them underdriven like that can lead to cathode poisoning. > It can be reversed, but it's disappointing when it happens. > > - John KG4L -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To post to this group, send an email to neonixie-l@googlegroups.com. To unsubscribe from this group, send email to neonixie-l+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/neonixie-l?hl=en-GB.
