[sdiy] Buchla 144 dual square wave oscillator

[Donald Tillman]

   > From: "Jerry Gray-Eskue" <jerryge at cableone.net>
   > Date: Fri, 26 Jun 2009 13:53:58 -0500
   > 
   > Complements, this is a nice detailed analysis.

Thanks.

   > So I take it that the flip-flop is a Toggle type providing a
   > divide by 2 of the oscillator frequency?

I was going to suggest Wikipedia..., but man, the Wikipedia Flip Flop
page is confusing mess.

The flip flop here has two transistors, and two stable mirror-image
states that it can be in -- each state has one transistor on and one
transistor off.  A single pulse input causes the flip flop to switch
from one state to the other.  Hence the name "flip flop".  And so a
flip flop will convert a string of pulses into a square wave.

And since two state changes make a square wave, yes, it will divide
the original frequency by two.

Don Buchla could have just squared up the original sawtooth wave, but
he probably went to the trouble of using this approach so he could be
assured of of having a 50% duty cycle without any trimming.  Hence the
"square wave" in the title of the module.

  -- Don

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