analog lab #8

With the oscillator we are studying, the comparator outputs a square wave, and the integrator outputs a triangle wave.
With an integrator, if Vin is positive the output voltage ramps up. If Vin is negative the output voltage ramps down.
With a comparator, if the op amp’s + input is connected to a greater voltage than that connected to its – input, the op amp’s output will be about +9v DC. If the op amp’s + input is connected to a lower voltage that that connected to it’s – input, the op amp’s output will be about —9v DC.
The bigger the resistance R you use the slower the ramp gets, and the bigger the capacitor gets the slower the ramp gets.
To turn this monophonic synthesizer to a polyphonic synthesizer, I believe that you would need an extra comparator for each note of polyphony. For example, 8-note polyphony would demand 8 comparators, which explains why analog synthesizers are so infrequently polyphonic.