Hi, could it be possible to add an short delay in the reset to lighten the 6th cathode? eric _____
From: [email protected] [mailto:[email protected]] On Behalf Of threeneurons Sent: dinsdag 10 september 2013 11:14 To: [email protected] 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-driv er_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/dScs Fft7eqU/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]. 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/3f3b07d0-7ab6-4c94-86c9-262872a 81383%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/!%26!AAAAAAAAAAAYAAAAAAAAAPDddShx705MuX20yCpp0vvCgAAAEAAAAEQq4rQd/kFJqel4DdwUs08BAAAAAA%3D%3D%40zeelandnet.nl. For more options, visit https://groups.google.com/groups/opt_out.
