[sdiy] suboctaves

[Scott Gravenhorst]

matti <matti at devo.com> wrote:
>curently I'm using CD4017's to generate /2 and /3 subharmonics. This means
>six chips : quad opamp for quaring up, one 4017 for /2, one 4017 for /3,
>times two for both fatman voices.
>
>I'm wondering a few things : are there any chips that give multiple
>divided outputs? how do I accomplish /1.5?

I did /1.5 by multiplying first by 3 then divide by 2.  The
multiplication happens in a PLL.  This method will yield a
symmetrical waveform.

Also for a fatman, the 555 timer outputs a nice -12v pulse for
each reset on pin 3.  A CMOS counter setup to run from -12 
and ground can be connected directly to pin 3.  I used a 4027 
for my suboctave connected this way.  You could easily drive
your 4017s the same way and eliminate the squaring opamps.
Just put Vss to -12v and Vdd to ground.

>
>thanks
>
>
>-
>finland red
>germany black
>egypt white
>

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-- Scott Gravenhorst | LegoManiac / Lego Trains / RIS 1.5
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