Dave,
Thanks for your description.
Cheers,
Dennis
On 11/23/07, djbrow54 <davebr@...> wrote:
>
> The Kurzweil ribbon is actually three independent ribbon segments.
>
> One CVS output is for 5.6 volts to power the ribbon. I use a diode
> drop in the bottom leg so the ribbon output is 0.6 to 5.6 volts. That
> way I can detect 0 volts which means no contact with the ribbon. The
> other three outputs are CV, Trigger, and Gate.
>
> Three of the inputs are used for each of the ribbon sections. The
> middle ribbon is backwards so the software reverses the middle and
> pieces back the sections. I have a constant that I adjust to match the
> voltage drop of the diode and the piecewise continutity of the ribbon
> is pretty good. There are just very slight discontinuities as you
> switch from ribbon to ribbon.
>
> The fourth input is optional and is used with a potentiometer to
> control offset. I generally run the output of my ribbon to an offset
> module which will generate +/- 5 volts from the 0 to 10 volt output.
> The conversion is not perfect, so this offset allows me to 'dial' in 0
> at the exact center of the ribbon. For example, if I'm using the
> ribbon to FM an oscillator, I can press on the center of the ribbon,
> and dial in no modulation by listening to the oscillator. In a
> dedicated setup, this could be a software constant but I left it in.
>
> Of course modifying the software could give you three independant
> ribbons. You could add the second DAC and control circuitry to provide
> three independant CV, Trigger, and Gate outputs.
>
> Dave
>
> --- In ComputerVoltageSources@yahoogroups.com<ComputerVoltageSources%40yahoogroups.com>,
> "Larry T." <larry@...>
> wrote:
> >
> > Dave
> >
> > I curious why you have populated 4 input channels? What is the
> output
> > from the Kurzweil PC-2 controller? Could you actually populate even
> > less on the board for this dedicated use? I also noted the use of
> the
> > AtomPro 24 instead of the 28, good idea for this dedicated use.
> >
> > Larry T.
> >
> > --- In ComputerVoltageSources@yahoogroups.com<ComputerVoltageSources%40yahoogroups.com>,
> "djbrow54" <davebr@>
> > wrote:
> > >
> > > No one has mentioned a ribbon controller application. I have done
> a
> > > program that interfaces the Kurzweil PC-2 ribbon to my PSIM and it
> > > works pretty good. I bought my ribbon from Sweetwater for $50. I
> > > assume they still have them.
> > >
> > > The program outputs are a CV, trigger, and gate. This can be built
> in
> > > a depopulated CVS pcb and there is a photo in my photo album
> called
> > > "CVS special build configuration". I've got a second ribbon that I
> was
> > > going to use this PCB for, but haven't quite finished yet. Contact
> me
> > > for details if you are interested in building a CVS for a ribbon
> > > controller.
> > >
> > > Dave
> > >
> >
>
>
>
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