Triangle VCO and other tragidies

[patchell]

    I was hoping that there would be "none".  They are unequal, which is
probably going to make it just that much more fun.  They get a bit larger at
the higher frequencies (15KHz).  But yeah, I will have to uses some sort of
comp scheme to get rid of the charge coupling thru the JFET.  I also have a
funny oscilation that shows up at the high frequencies.  I was only able to
spend about a half hour playing with it once I was able to power it up.  And
it looks like the rest of the day is shot.....

Ian Fritz wrote:

> Jim --
>
> Good news! If you get a chance, I'd like to hear about what your switching
> transients look like. I've finally pretty much gotten rid of mine, using a
> compensation trick suggested on the ADG431 data sheet (see their cool
> precision S/H circuit). A similar trick might work with your discretes.
>
>   Ian
>
> ----- Original Message -----
> From: "patchell" <patchell at silcom.com>
> To: <synth-diy at node12b53.a2000.nl>
> Sent: Sunday, August 13, 2000 9:59 AM
> Subject: Triangle VCO and other tragidies
>
> >     I just finished breadboarding and powering for the first time the
> > Triangle VCO I proposed a couple of weeks ago.  This is similar to the
> > idea that Ian Frizt posted on his web site about a month ago now I
> > think.  Instead of using CMOS switches, I used J174 P-FETs.  All I wired
> > up was the core (no exponential converter), and all I can say at the
> > moment is that it makes a triangle.  I have other things to attend to at
> > the moment, and hope to get back to it latter today to fix some minor
> > problems (it jitters at the moment), and to make some measurements, like
> > delta offset versus frequency.
> >
> >

--
 -Jim
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