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From: wiml@blake.acs.washington.edu (William Lewis)
Newsgroups: sci.electronics
Subject: Frequency divider (audio)
Keywords: analog weirdnesses
Message-ID: <3923@blake.acs.washington.edu>
Date: 5 Oct 89 06:12:45 GMT
Organization: Univ of Washington, Seattle
Lines: 30


   Hello, I need some help from those people out there who understand
analog circuitry (in depth, I mean...)  I'm trying to build a simple
circuit to divide the frequency of in incoming (audio) signal down
an octave or several. What I was thinking of doing was to digitize the
signal with a comparator of some sort, feed that through a flip-flop
or two, and then put capacitors across and in series with the output
to re-"analog"-ize it. (ie, chop off the aliasing frequencies with a
capacitor across the outputs, and remove any dc using a capacitor 
in series. Plus a volume control and such of course.)
   Now the question is... Would this work? Would it work reasonably well?
The signal it's to be dividing is a normal audio signal (speech, music,
etc.) which I'd expect to have a pretty complex waveform. Would this
1-bit digitization introduce huge amounts of distortion? (A little is
OK, but I want to be able to understand what's coming out). Is there a
better way to do this? (if so, what?) I feel more at home with digital
stuff (and low speed. All I want to see are pullup resistors and
bypass capacitors on the power supply =8) ) so if you reply,
"Oh, that's easy, just use a Boyglesthibben circuit" explain to me
what a Boyglesthibben circuit is...

   Anyway, thanks in advance for any help / suggetions... if you feel
this is too unusual a request to be broadcast, email and I'll
summarize...

     --- phelliax
         "To Forbid is to Suggest"  (... a guy I know, and others too)

-- 
wiml@blake.acs.washington.edu        (206)526-5885      Seattle, Washington