Electronic Siren 2
Did you like our Ear splitter? see in Oscillator Section. Well, as the old saying goes, "you ain't heard nothing yet!"
Turn the power ON and press The Key. You'll hear the sound from the Speaker slowly build step-by-step until it reaches a mindboggling peak.
Release the Key, and the volume from the Speaker will gradually diminish and eventually stop.
Carefully compare the schematic of this Project with that of our last Project Chirping Bird in Oscillator Section. What's the biggest difference you can spot?
Try some other ways of changing the current to the base of the right Transistor and see what other sounds you can comne up with. You can adapt this circuit for other applications ... wouldn't this make a terrific door or other alarm?