tlfong01 wrote: ↑Sat Dec 15, 2018 12:56 pmPre-requisites for guessing how the weird buzzer oscillates
https://www.electronics-tutorials.ws/os ... ators.html
Buzzer schematic 70% sure, brain storming guessing welcome
I think my background knowledge in inductance and feedback is far from adequate to understand what is going on. I don't even know where to start a wild guess.
Perhaps I can start looking at time period d-a
1. Time interval d-a: Q1 fully saturated, Ic = Ice(sat), Vc ~= 0.
2. Time point a, base suddenly drops from 0V to -10V (why not say, 2V to 0V?) Q1 suddenly cut off, connected inductor L2 has back EMF 25V (fives times of Vcc = 5V is what I usually read, though I don't know how to calculate).
/ to continue, ...