The amplitude of input 1 is compared to input 2 and when the difference is less than the window size, the output is high
Add some interest to an oscillator as a sidechain processor that creates frequency tracking non-linearities.
This deceivingly simple circuit can be used in many configurations:
Pulse wave generation with new flavor of voltage controlled PWM shifting between root and one octave up
Generate (multiple) sub-period events
Create evolving rhythmic patterns
Add looping to any re-triggerable envelope with voltage control over the loop point
Use with an envelope to create a voltage controlled event delay
