by Benna Su.
1) With the oscillator we’re studying the comparator outputs a square wave and the integrator outputs a triangle wave.
2) With an integrator, if Vin is positive the output voltage ramps down (up/down). If Vin is negative the output voltage ramps up (up/down).
3) With a comparator, if the op amp’s + input is connected to a greater voltage that that connected to it’s – input, the op amp’s output will be about positive (positive/negative) 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 negative (positive/negative) 9v DC.
4) There’s a formula for how fast the integrator ramps up or down:
change in volts per second at Vout = -Vin / RC
So the bigger the resistance R you use the faster (faster/slower) the ramp gets, and the bigger the capacitor gets the faster(faster/slower) the ramp gets.
5) The circuit at the end of this video is a monophonic synthesizer – it can only output one tone at a time. What do you think would have to do to make a polyphonic synthesizer that could play 2 notes at the same time? 3 notes? 4 notes? 100 notes?
I think if it wants t play more notes, you have to make multiple inputs in integrator, and each input has the same set up of adjusting the speed of ramp up and ramp down.
Benna Su Electronics labreport 