This circuit from a Popular Electronics from the 90's can generate signals from 0.03 Hz to 3 kHz depending on the value of the capacitor and resistor.
This battery monitor circuit with the TLV379 low voltage operational amplifier was obtained in the...
We got this circuit from Radio Electronics from July 1990. The circuit mimics the sound of the red...
This configuration often addressed on this site is from a 2000 documentation. The circuit can be...