[sdiy] What is a quadrature oscillator good for?

[Don Tillman]

   > From: "jhaible" <jhaible at debitel.net>
   > Date: Tue, 16 Sep 2003 02:33:16 +0200
   > 
   > > Ooops, sorry, you mean leakage in the form of a resistance.
   > >
   > > Sure, that shows up as if the rotating object had a very slight
   > > amount of spring to cause it to drift to certain position.
   > 
   > In your Leslie example, will the position stay fixed over
   > 20 minutes (because you play 3 songs with the organ
   > thru leslie in stop position) ?

20 minutes?  Sure, but not with any accuracy.  I certainly don't have
any breakthrough technology to hold capacitor voltages steady.
But... at least it won't drift more than a quarter cycle.

Even if it does drift, the correct TrapezoidSin -- TrapezoidCos phase
relationship is still maintained.

It is possible to put the quadrature trapezoid VCO into a parked
position with some additional analog switches, and have an ADC/DAC
arrangment store that position, if such a feature was especially
important.

  -- Don

-- 
Don Tillman
Palo Alto, California
don at till.com
http://www.till.com