Yes, though for the purpose I described, its working just as it should. This is how the asynchronous reset works on most modern logic chips. If you want a 4017 to count from 0 to 5 (Q0 to Q5), you connect the reset to output "Q6". But if you stick a small cap across that 10K resistor, that's across the BE junction of the transistor generating K6, it should glow momentarily.
On Tuesday, September 10, 2013 6:36:06 AM UTC-7, Tidak Ada wrote: > > Hi, could it be possible to add an short delay in the reset to lighten > the 6th cathode? > > eric > > ------------------------------ > *From:* [email protected] <javascript:> [mailto: > [email protected] <javascript:>] *On Behalf Of *threeneurons > *Sent:* dinsdag 10 september 2013 11:14 > *To:* [email protected] <javascript:> > *Subject:* [neonixie-l] Re: A107 Dekatron > > Added a reset circuit, so it will count from 0 to 5, then reset to 0: > > > http://www.dailymotion.com/video/x14htr2_a107-divide-by-6-nixie-counter-driver_tech > > > Well, actually it transiently hit 6, but then quickly resets to 0, so you > never see the 6 > > <https://lh6.googleusercontent.com/-NmK2j_FZo-I/Ui7eBajyPJI/AAAAAAAAMFs/dScsFft7eqU/s1600/A107_Nix_dvr6.gif> > > The reset is done by raising all cathodes well above ground, while the > zero cathode remains the only one at ground, and therefore forcing the glow > to it. This circuit only resets from even cathodes. 6 in this case. Then > the odd cathodes are already off. A single MPSA42 disconnects cathodes 2 > thru 8. If this was a real divide-by-6, 8 would not be connected, at all. > K6 turns off that MPSA42, but not directly, even though its in the proper > state. It has to actually drop to at least the value of the low flip-flop > output. To ensure that this happens a non-inverting buffer made of two low > voltage transistors (PNP, 2N3906 & NPN, 2N3904) are used. Resistor values > are chosen so when K6 drops below 20V, the 2N3904, goes to its saturation > level (~0.5V max). This will pull the base of the added MPSA42, well below > its emitter, guaranteeing that its turned off, disconnecting all the even > cathodes, except 0. > > I Think the 12 hour, hours section can be done only needing one dekatron, > and the addition of a flip-flop. So 5 A107 dekatrons (or 108s, or 109s) are > needed to do a 6-digit clock. This circuit will be very similar to Mike > Harrison's circuit, but with the dekatron flip-flop groups replacing the > 4017 CMOS chips: > > http://www.electricstuff.co.uk/nixclock.html > > > > > > -- > 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] <javascript:>. > To post to this group, send an email to [email protected]<javascript:> > . > To view this discussion on the web, visit > https://groups.google.com/d/msgid/neonixie-l/3f3b07d0-7ab6-4c94-86c9-262872a81383%40googlegroups.com > . > For more options, visit https://groups.google.com/groups/opt_out. > -- 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 post to this group, send an email to [email protected]. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/4d2d4cd4-654b-46f1-b185-cafac4650e7e%40googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
