[sdiy] Adding "sync" to a Through-Zero Sinewave Oscillator design

[Richie Burnett]

Donald Tillman wrote:

> I'll claim that reversing the direction of the wave is not actually a 
> sync.  The word "synchronize" means to bring an oscillator to the same 
> frequency, and same phase, as another.  I don't think that's remotely 
> possible by flipping the direction of the triangle every cycle.

> I'd even call it "anti-sync".

I'd call it FM.  By reversing the direction of any waveform you are changing 
it's frequency from +f to -f or vice versa.  So one way to look at it is 
Frequency Modulation by a square wave.

-Richie,