LM3900 - was :[sdiy] IN your mind, what is ....

[Tim Parkhurst]

I've seen schematics for using the 3900 as a voltage controlled current
source and/or sink (Forest Mimms book, I believe). Could this be the core of
a voltage controlled EG? I'm thinking this is a VERY simple way to control
the charging current for a cap, but am I oversimplifying things?

Tim (oversimplified) Servo
"Imagination is more important than knowledge." - Albert Einstein

********************************************
> -----Original Message-----
> From: jhaible [mailto:jhaible at debitel.net]
> Sent: Thursday, January 29, 2004 12:35 PM
> To: Grant Richter; Joel Kirchartz; synth-diy at dropmix.xs4all.nl
> Subject: Re: [sdiy] IN your mind, what is ....
> 
> In Fredriksen's book "Intuitive IC Opamps"
> he calls the LM3900 "the first Quad".
> 
> So maybe the main reason for its popularity was
> that it simply was the first opamp that only took
> 1/4 of a DIP 14 package?
> 
> (Fredriksen designed the 3900, and also these
> other "classics", LM324 and LM339.)
> 
> JH.
> 
> 
> 
> -----Ursprüngliche Nachricht-----
> Von: Grant Richter <grichter at asapnet.net>
> An: Joel Kirchartz <joel_kirchartz at hotmail.com>;
> <synth-diy at dropmix.xs4all.nl>
> Gesendet: Donnerstag, 29. Januar 2004 21:13
> Betreff: Re: [sdiy] IN your mind, what is ....
> 
> 
> > The LM3900 current differencing amp.
> >
> > Probably more applications than a regular op-amp.
> >
> > Serge Tcherepnin built a large part of the Serge system from them.
> >
> > From: "Joel Kirchartz" <joel_kirchartz at hotmail.com>
> > Date: Thu, 29 Jan 2004 14:49:31 -0500
> > To: synth-diy at dropmix.xs4all.nl
> > Subject: [sdiy] IN your mind, what is ....
> >
> >
> > What is the most versatile chip (be specific) ?
> > Why do you think so ?
> >
> > ~kirch
> >
> >
> >
> >
> > Let the new MSN Premium Internet Software make the most of your
high-speed
> > experience. <http://g.msn.com/8HMAENUS/2743??PS=>
> >
> >
> >




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