Using 555 integrated circuits, this alarm circuit was found in a 90s American documentation. The signal must be applied to a good audio amplifier.
This reverb effect was found in the December 1961 Radio Electronics magazine. It makes use of...
Found on Popular Electronics from the 1990s, this oscillator uses a general purpose transistor. The...
This simple 741 circuit was found in the August 1993 Electronics Now magazine. The source must be...