This percussion circuit was found in an Electronics World of 1968. The transistor may be general purpose and the power supplied at 12 V. The signal must be applied to an amplifier.
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...