Warble-tone alarm

Posted on Jan 13, 2013

The circuit generates a warble-tone alarm signal that simulates the sound of a British police siren. IC1 is wired as an alarm generator and IC2 is wired as a 1 Hz astable multivibrator. The output of IC2 is used to frequency modulate IC1 via R5.

Warble-tone alarm
Click here to download the full size of the above Circuit.

The action is such that the output frequency of IC1 alternates symmetrically between 500 Hz and 440 Hz, taking one sound to complete each alternating cycle.

Leave Comment

characters left:

New Circuits



Popular Circuits

600W rf power amplifier
supernode dependent voltage source
digital room thermometer using lm35 sensor 8051 microcontroller
Astable Multivibrator
FM IF MW radio receiver circuit using LA1260 integrated circuit
Crank Doorbell Circuit Schematic
2001 chevy s10: indicator light headlight switchfuserelay bulbs
Stand-alone Arduino
Circuit Power transmitter of communitarian wireless TV lm1889 audio and video