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.
The configuration presented below was obtained in the Linear Application Handbook of the National...
This circuit was found in December 1983 Radio Electronics magazine. The maximum output current is 1 A...
This untuned circuit uses one of the world's first commercial transistors, the CK722, having been...