Police Siren Using 555 Timers

This post presents circuit which produces a long up and down variation of the sound that similar to police siren. Circuit is based on two 555 timers which operates in astable mode. In this mode a square wave output is generated.


1.Power supply (9V) 1
2.555 timer2
3.Piezo buzzer1
4.1kΩ resistor1
5.10kΩ resistor3
6.68kΩ resistor1
7.10μF electrolytic capacitor2
8.100nf ceramic capacitor2

Circuit diagram

Police Siren Using 555 Timers (Circuit Diagram)

Designed circuit

Circuit is designed on a breadboard.

Police Siren Using 555 Timers (Designed Circuit)

Leave a Comment

Your email address will not be published. Required fields are marked *