Found in a Popular Electronics from the 90s, this circuit presents the difficulty of obtaining the Geiger Tube. The other components are common, admitting equivalents.
This oscillator circuit for sinusoidal audio signals with operational 741 requires a symmetrical power...
Found in a 1974 Radio Shack documentation. This circuit must have a connection to the ground of...
This sensitive circuit detects the live pole of a power grid or outlet. The circuit makes use of a high...