> The BCD boards look to have 8 transistors arranged as four flip-flops. This > makes the decoders easy, as the flipflops have Q and not-Q outputs for each > stage, so a simple wire-and lashup with some diodes will do the trick. Cute > construction with the long narrow board perpendicular to the other board, > with the nixie on it. >
That is correct, I made a sub circuit called DIV2FFN. It's a very advanced flipflop with just 2 transistors! It supports pre-settable inputs, edge triggering, division by 2, very smart design! http://xiac.com/Images/DIV2FFNblock.JPG The circuit has 4 of these connected to each other as in this schematic: http://xiac.com/Images/BCD_CNT.JPG The counter counts F-E-D-C-B-4-3-2-1-0, which is most likely done to save some transistors in the decoder. Michel -- 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.
