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.
We found this circuit in a 2005 Linear Technology manual. The resistor is calculated for the...
The frequency of this circuit is determined by the 100 uF capacitors. These components can be...
This circuit appeared in the July 1969 issue of Radio Electronics magazine. The sensor is an LDR....