This simple musical horn can be used in a car, scooter, cycle, or motorbike, or even as a call-bell. It uses melody generator IC UM66 that generates a musical tone, which is amplified by IC LM386. The tone of the horn cannot, however, be changed as no potentiometer has been used to keep the circuit simple. The author’s prototype is shown in Fig. 1.
Circuit diagram of the musical horn is shown in Fig. 2. The circuit comprises a bridge rectifier (BR1), 9V voltage regulator 7809 (IC1), melody generator UM66 (IC2), low-power audio amplifier LM386 (IC3), and a few other components. Capacitors connected across the supply terminals are used to minimize any noise signals.