The buzzer I'm using is a 3-20V range buzzer. Rated voltage 12V, max current 20ma. I have wired the buzzer to arduino output pin directly. Without any resistor.
My problem is that, after about 10-12 mins of beeping (short and long beeps followed by pauses), the tones become somewhat distorted, some random noises are generated by the buzzer, that sounds like jamming sounds. But if I power down the project and try again a bit later, I can get a clear sound again for 10-12 more minutes.
What could be the reason? Any ideas? Too much current is being drawn? The output pis are getting damaged or can it not keep up with current demand or what?