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Subject: RE: [ComputerVoltageSources] Re: resistor matching

From: "John Loffink" <jloffink@...>
Date: 2006-03-26

Yes, using a MIDI-CV converter with 12 bit or better resolution, which is
most of them.

John Loffink
The Microtonal Synthesis Web Site
http://www.microtonal-synthesis.com
The Wavemakers Synthesizer Web Site
http://www.wavemakers-synth.com


> -----Original Message-----
> From: ComputerVoltageSources@yahoogroups.com
> [mailto:ComputerVoltageSources@yahoogroups.com] On Behalf Of Larry T.
> Sent: Saturday, March 25, 2006 11:17 PM
> To: ComputerVoltageSources@yahoogroups.com
> Subject: [ComputerVoltageSources] Re: resistor matching, was RE:
> Calibrated Inputs
>
> Okay. But could you use the output of a MIDI-CV converter or a CV
> keyboard as your reference and still use this method? It should still
> be consistant across all inputs right?
>
> LArry
>
> --- In ComputerVoltageSources@yahoogroups.com, "John Loffink"
> <jloffink@...> wrote:
> >
> > For calibration you need to measure an amplified value, even if the
> > amplification is 1. You can't do that by grounding the signal.
> That just
> > sets the zero null point.
> >
> > John Loffink
> > The Microtonal Synthesis Web Site
> > http://www.microtonal-synthesis.com
> > The Wavemakers Synthesizer Web Site
> > http://www.wavemakers-synth.com
> >
> >
> > > -----Original Message-----
> > > From: ComputerVoltageSources@yahoogroups.com
> > > [mailto:ComputerVoltageSources@yahoogroups.com] On Behalf Of Larry T.
> > > Sent: Saturday, March 25, 2006 8:03 PM
> > > To: ComputerVoltageSources@yahoogroups.com
> > > Subject: [ComputerVoltageSources] Re: resistor matching, was RE:
> > > Calibrated Inputs
> > >
> > > Thinking about it, I believe this would also account for varrainces in
> > > the ADC's thenselves would'nt it?
> > >
> > > Larry T.
> > >
> > > --- In ComputerVoltageSources@yahoogroups.com, "Larry T." <larry@>
> > > wrote:
> > > >
> > > > HI All
> > > >
> > > > Given that I'm not an EE or even a decent hobby designer, why is
> this
> > > > calibration such a problem? Why not use trim pots and the Analog
> > > > inputs themselves as follows:
> > > >
> > > > First: Ground the input to be calibrated. (This should ALWAYS be a
> > > > constant of 0 right?)
> > > >
> > > > Second: Run a small program on the modules CPU to continously return
> > > > the value of the converters input via the serial port to a 'telnet'
> > > > session on a PC or Mac, followed by a Carriage Return and a Line
> Feed.
> > > > (This will give you a continous dump of the converters value
> down the
> > > > screen.)
> > > >
> > > > Third: Adjust the timpot until you get 0.00... as the returned
> value,
> > > > and it stays that way for a minute or two.
> > > >
> > > > Would'nt this handle it with NO tools of any kind except those we
> > > > already need to use the module anyway?
> > > >
> > > > Larry T.
> > > >
> >
>
>