[sdiy] crazy CMOS behavior

[Scott Gravenhorst]

I'd check that your clock converter is not producing glitches.  I'd use
an oscope set to synch on the actual input clock pulse and display the
clock signal fed to the actual counter IC.  Look at the signal at ever
decreasing sweep times.  There should be one obvious pulse per synch, not
several.  A dual trace scope makes this easier.  If you get multiples,
then something is not right with the converter.  If the input clock has a
slow slewing "edge", it may glitch whilw in transit.  A schmitt trigger
input device clears this.

mark verbos <a0284520 at addcom.de> wrote:
>I have built a sequencer based on the 4516 counter. The clock input is 
>stolen from the Serge TKB schematic that is on music machines. That is, 
>trough a cap to an NPN then a CMOS inverter then to the counter. When I 
>clock it, with anything, it jumps all over the place with no real sense 
>or pattern. Could this be related to the step length not being right? 
>How does it work for the actual Serge? It's not the chips, I have 
>switched them all out and it does the same tihng. Am I just missing 
>something not grounded or something?
>
>thanks for any ideas, I'm going nuts here.
>
>mark
>

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