This circuit mimics the heartbeat with the softest sound played through a small speaker. The circuit is from an Electronics Now issue of January 1997.
This simple circuit can be used to power a simple communication system using ordinary telephones....
This circuit was found in a Popular Electronics from the 90s. The components admit equivalents and the...
This simple circuit makes use of a buzzer with a 6 V oscillator, compensating for the 2 V voltage...