2 tones Siren

Components :

                Resistor                    : R1 47k

                                                : R2 100k

                                                : R3 1k

                                                : R4 22k

                Capacitor                 : C1 0.01 µF

                                                : C2 0.01 µF

                                                : C3 10 µF /16V

                                                : C4 1 µF / 16V

                IC                            : NE 555

With IC NE 555 you can make bell sounds. Bell sounds have two tones. Low or high the tone dependent from R1, R2 and C1 Value. IF you want to change the tone, you must change R1, R2 and C1 Value

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