I just wanted to thank everyone for the helpful comments on this thread, and provide a brief update. Although I still have a ways to go in terms of solidifying my VFD PSU plans, I had an exciting night in VFD land. I built a simple voltage multiplier as suggested out of two diodes and two capacitors and plugged in a 12VAC as input. I got out around 36 volts DC based on the caps I used (I am assuming that is the reason it was not closer to 24volts. I didn't know any values offhand to use, so I tried 1uF caps I had lying around that were good for 50V.
Since I was just breadboarding 1 IV-11, I decided on a very quick and dirty 1.5V battery hooked up to the cathodes. I was very excited to see a number 8 and a decimal light up after giving power to all the anodes! It's a babystep, I know, but it was an important move forward in my VFD explorations. Happy New Year to all! On Tue, Dec 20, 2011 at 4:34 AM, fixitsan <[email protected]> wrote: > > > On Dec 19, 7:37 pm, John Rehwinkel <[email protected]> wrote: > > > Power each tube's filament in parallel from the 5v supply, in series > with a voltage dropping resistor. > > It also has the advantage to soft-starting the filaments - cold > filaments have low resistance and draw heavier current until > > they warm up. The series resistors limit this current surge. > > > > - John > > This is how I do it for the IV-17 explorer kits I sell. > I have tubes which have run for a couple of years now without any > problem. in the muxh there is no visible signs of any gradient and > even when the tubes are not muxed it is still true. the filament > begins in the lower left of the tube, rises, folds over at the top of > the tube and comes down to the pins again on the right side. Any > gradient should be seen as a different in brightness of the left and > right sides at the tube's base. > I suspect that because of the close proximity of segments at the base > to both sides of the heater (the higher voltage end on the right and > the lower voltage end on the left) some sort of smoothing also takes > place to even out the difference. > > Shorting out a resistor (in my case 1/2W 1210 SMD parts) would case > the tube filament to receive too much voltage. I think I will add a > note in my instructions so that builders protect those components > well, if not with a case then a protective coating of some sort. > > Perhaps in the next revision i'll think about putting those resistors > on the underside to really protect them well > > Chris > http://groups.yahoo.com/group/smartsockets/ > > -- > You received this message because you are subscribed to the Google Groups > "neonixie-l" group. > To post to this group, send an email to [email protected]. > To unsubscribe from this group, send email to > [email protected]. > For more options, visit this group at > http://groups.google.com/group/neonixie-l?hl=en-GB. > > -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To post to this group, send an email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/neonixie-l?hl=en-GB.
