Well, those who know me, know that I have attraction to dekatrons. Here's some of my latest tinkering. A long while back I designed a 4000 CMOS base pendulum circuit. It used a 4017 counter, and a 4013 flip-flop. I revisited that circuit, and came up with one that just uses on 4518 dual counter:
<https://threeneurons.files.wordpress.com/2011/08/pendulum16.jpg> In addition to the one chip, and the HV interfacing transistors, there's a clever little piece of what Don Lancaster referred to as "Mickey Mouse logic". The one transistor and its associated components, in the pink field, form an exclusive-OR gate. Half the chip along with XOR ckt, make the guide timing circuit. The other half of the chip is used as the direction flip-flop. Circuits quite nicely. HV supplies, and clock, not shown. In my test circuit, I decided to run two dekatrons. One master, and one slave. To align the slave tube, I added a reset circuit to K0 (normally used as the NDX). This forces the glow to K0, instantly. Here's that portion of the circuit: <https://threeneurons.files.wordpress.com/2011/08/dek_rsts.jpg?w=500> I hooked it such that when QD (pin 14), of the IC went high, the reset was issued. That meant a reset every 10 'flips'. It worked ... mostly. I noticed something strange. If I used a A101 as a slave, the glow reset to K0, as expected. But using several 6802's and a GC10B, the glow appeared to reset to K9. After some poking around, I decided to check the reset, with the guides (G1 & G2) off. Then, indifferent to tube type, the reset forced to glow to K0. So this new pendulum circuit "backsteps" some tubes from K0 to K9, almost instantly. Here's a photo of the test circuit, and video of it running: <https://lh3.googleusercontent.com/-5KlqWhp-GzA/V7OLpDoOm6I/AAAAAAAAYa0/oxM3bGbKbS8CxBm5TxYXDf-PU5ipDSY6gCLcB/s1600/Pendulum2xs.jpg> Video <https://www.youtube.com/watch?v=csGUc6bfuG0> of above circuit. Enjoy -- 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/d98cb682-5c9d-44d0-b912-f5865ae62a8a%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
