This circuit with a dual power supply generates sinusoidal, triangular and rectangular signals. We found it in the magazine Electronics Now of January 1996. The frequency goes up to a few megahertz.
This modulated light transmitter was found in a 90s Popular Electronics. In place of the lamp with...
The circuit shown here produces a pure square tone of 440 Hz that is suitable for musical...
This circuit of an old publication produces the insect-like noise that drives them away. The...