Help with OP amps
Secondly, the comparator "rings", it doesn't displays a clean square signal when the threshold is reached, instead, at the end of the square pulse "ringing" appears. Removing the buzzer or speaker solves the ringing problem.
I tried replacing the buzzer by a 8 ohm speaker, but the problem persists. Then I tried changing the 1k resistor of the transistor by a 10k, but the problem is still the same.
I don't know what could be causing this, bad design? A faulty chip?
In the second picture it can be seen how the signal "bumps" an invisible barrier when reaches the comparator level, in the third the "ringing" can be seen, the fourth and last picture is how the (previous) comparator signal looks when the load is removed, the problem disappears.
Thanks in advance,