Electronic buzzer circuit is built with basic components 555 timer IC as an audio frequency generator. 555 timer arranged as astable multivibrator circuit and works for frequency +/- 1kHz, so that the output of this circuit can be heard by the ear.
The frequency of The Electronic buzzer circuit can be adjusted with replaced the 10K resistor with others value, but if you want to make it easier, 10k resistor can be replaced with a variable resistor, just keep in mind this circuit will not be far from 1kHz. The recommended voltage supply for this circuit is + 5V to 15VDC. For the user, this circuit is typically used for general purposes such as the alarm circuit, buzzer quiz, or specific warning sign that as indicators when a switch has been connected.
Electronic buzzer circuit is very easy to built because it requires a small component only, so that is practical for the purposes of Mobile with a battery power sources.