DC & Buzzer

1. Have you ever examined how a buzzer is constructed? If your buzzer is covered, have you torn it apart to see what is there? Everyone should do that at least once. Inside you should see an electromagnet coil and switch contacts. Draw a schematic of the whole thing and tell us how you think it works.

2. When an electrolytic capacitor is used to pass AC it is usually the case that the AC is superimposed on a larger DC voltage so the capacitor sees the AC as just just higher and lower values of DC voltage. But this is where the capacitor equivalent series resistance ESR becomes important since the AC component of the DC voltage results in an AC current flowing through the ESR generating heat. Too much heat will destroy the capacitor.