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 oscillator can generate 2 to 10 MHz signals and was found in an American 1980s documentation. The...
This flasher was originally intended for Christmas tree lamps. The circuit is from 1974 and uses...
In the figure we have the way to add hysteresis to an operational amplifier. The relationship...