Maybe it would be possible to reduce the size without changing too much to these distances and pressures. For example, if you would let the cathode pins come out of the side of the tube rather than the bottom, you'd probably save about 7-8mm already. So you don't need to modify the current grid setup too much in order to come down to something close to 12.5mm.
Michel On Jan 29, 9:26 am, jb-electronics <[email protected]> wrote: > It is not that easy: > > The product of pressure and electrode distance determines the striking > voltage (Paschen's curves). It is roughly U_strike ~ [p*d]^2 where p is > pressure and d is distance. If you decrease the distance, then you have > to use a higher pressure to obtain the same striking voltage. The higher > pressure condenses the glowing and makes it not as visible as before. > The alternative - a higher striking voltage with the old pressure - is > also not a good idea since you will have sparkovers in your tube that way. > > I am not saying it is impossible, I just want to make the point that > most dimensions found in a commercially made Nixie tube are results of > long development. > > Jens > > > > > > > > > Yes, if you could manufacture new NL-4998 tubes that were only half > > the height of the original ones (12.5mm versus 25mm), you would end up > > with a tube that had great potential for wristwatch applications! > > > On Jan 29, 8:51 am, jb-electronics<[email protected]> > > wrote: > >> I do not think that it is possible to make much smaller Nixie tubes than > >> the NL-4998 which is basically the tiniest Nixie tube ever made. The > >> problem is the glow discharge, it is always larger than the cathode, and > >> you cannot make the cathodes too small because otherwise you wouldn't be > >> able to discriminate between the digits - it would be much too blurry. > > >> Panaplex displays are much more suited to these dimensions, sadly. ;-) > > >> Jens > > >>> I totally agree with that but I guess the old machinery no longer > >>> exists so it's going to cost quite a bit to setup a new production > >>> line for micro sized nixie tubes. I can't really see the micro nixie > >>> tubes being used in anything else but a retro style application, so > >>> the market for a tube like that will be very small. > >>> On Jan 29, 6:57 am, kay486<[email protected]> wrote: > >>>> Id really like to see the finished watch! It would be really awesome > >>>> if somebody made new tubes using modern technology so they could have > >>>> much smaller digits, and being able to have them lit all the time, > >>>> just like normal digital watches. > >>>> Cant wait to see your design. -- 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.
