SIMPLE MULTITONE SIREN CIRCUIT

Devices such as Burglar alarms and sirens, whose basic purpose is to monitor certain conditions make enjoyable projects because of the variety of sounds they can generate. Here we are going to discuss a simple dual tone alarm/siren circuit using a dual op amp MC1458, audio amplifier LM380, and a 1-W speaker. The dual op amp is used as a signal generator that produces square, pulse and triangular or sawtooth waveforms.

CIRCUIT SCHEMATIC FOR DUAL TONE SIREN

WORKING PRINCIPLE

The IC MC1458 dual op amp, is capable of generating various wave forms. The 20K POT controls the frequency and type of output waveform it will generate. The switch sw connects the dual op amp to the audio amplifier LM380, which in turn drives the speaker.