Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!decwrl!fernwood!edsel!till
From: till@lucid.com (Don Tillman)
Newsgroups: sci.electronics
Subject: Re: Square to Sawtooth
Message-ID: <1942@edsel>
Date: 29 Mar 89 19:30:11 GMT
References: <7476@thorin.cs.unc.edu>
Organization: Lucid, Inc. Menlo Park, CA
Lines: 19


   From: rohlf@unc.cs.unc.edu (John Rohlf)
   Date: 28 Mar 89 23:08:54 GMT

   Given an externally generated square wave of varying 
   frequency(audio range) and varying amplitude, what is the best/
   easiest way of converting it to a sawtooth of the same frequency
   and amplitude? 

Have a ramp preset to the square wave's high voltage level at the
square wave's rising transition.  Slew the ramp down from that point.
Electrically adjust the slew rate so that the ramp crosses zero at the
square wave's falling transistion.  This could track correctly after a
cycle or two.

The ideas I threw out both involved generating a voltage proportional
to the square wave's frequency first: either use that voltage to
adjust the ramping rate from the square wave's high voltage or drive a
voltage controlled integrator.  Neither way is real accurate.