This electronic gong circuit simulates the sound of a bell or a gong; The circuit consists of a resonant filter, built around IC2 and IC3, which rings at its resonant frequency when a short pulse is fed to the input. In this circuit the trigger pulse is provided by a 555 timer connected as a multivibrator, but other trigger sources may be used depending on the application. The character of the sound is influenced by two factors: the ‘Q’ of the filter, which may be varied by changing the value of R2, and the duration of the trigger pulse, which may be adjusted using P 1. The repetition rate of the trigger pulse, i.e. the rate at which the gong is ‘struck’. may be varied. using P2. In order to drive a loudspeaker, the output of the electronic gong circuit must be fed through an audio amplifier. The output level may be varied from 0 to 5V by means of P3.