This simple electronic bicycle horn circuit uses only one gate of a 4093 quad 2-input NAND Schmitt trigger, U1, conected in a simple, low frequency, square-wave oscillator circuit.
The oscillator’s output, at pin 3, drives the gate of Q1. The drain of that FET drives a small horn speaker.

Potentiometer R1 can be adjusted to set the More >

Post from: Electronic circuits and projects

Electronic Bicycle Horn