clock divider

cyborg0 at GlobalEyes.net cyborg0 at GlobalEyes.net
Fri May 22 02:50:34 CEST 1998


Maybe you have ripple (no, not the kind that fred sanford drinks!)
in your power supply..
That recently sent one of my trigger experiments a'crashing.. 
As Vcc ripples, the amount of voltage needed to trigger an input
changes.
Try checking the PS voltage as the thing begins to trigger with the
different divisions and see if the ripple changes as the load increases.
The PS is always the first thing i check when the unexpected occurs esp
with digital and trigger type circuits...
OR, perhaps your trigger gates from some of the dividers are too long or
too short, with this, one of two things can happen..
They will stay in a constantly triggerd state or not trigger at all.
I would say, see if you can get ONE divider (1/2) to work reliably, then
add another (1/4), then add the next one, and so on until you get into
trouble..This MIGHT show that one of your 4017s is bad, which is another
possibility.
Honestly, though, there are much more elegant ways of doing this sort of
division.. I think PLLS, maybe a shift register, or binary counters with
a ROM or discrete (gates) masking would be better suited for this.
Go digital on it. I think it will make your life easier, but it might
require a different type of thinking. If you can get hold of a digital
electronix textbook, they could show you quite a few innovative ways to
do this.
rob

Yoshiki Ohmura (Yoshi) wrote:
> 
> OK I gave it a shot, and tried to use the 4017 chip to divide the 24ppq
> signal from sync.  I basicaly chained 5 of them together to get me 1/16,
> 1/8, 1/4, 1/2, and 1/1 notes.  However that totaly bombed :( maybe it has
> something to do with the way these chips switch to logic 1 or something?
> Actually i have no idea.  has anybody succesfully built a clk div with
> these chips?  Or are there better chips out there to do it with?  Another
> thing, I layed a 4017 out on my breadboard to experiemnt with it, by just
> sending the logic signals to different led's, to see how that worked.
> Then i took my SH-101 (only thing  have that sends gate) and used it as an
> input.  after a couple passes through the sequence, I would notice that
> the chip would crash, until I reset itb by turning the power off.  Any
> ideas of why that was happening?
> 
> thanks for the help
> 
> Cheers
> 
> Yoshi



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