This simple circuit helps to make louder horn for vehicle or alarm, this circuit constructed by two timer IC555 and the output sound produced through 8Ω loud speaker.
Circuit diagram for electronic horn circuit
Construction and Working
Here first timer IC produce pulse output and second timer IC produce high frequency pulse then the output from the second timer IC fed to the loud speaker. The resistor R4 and R5 reacts as a timing resistors for first timer IC by varying R5 variable resistor we can vary the pulse duration.
Here R2 resistor reacts as a timing resistor for second timer IC by varying R2 we can get different tone horn at output.