This 1 kHz filter was found in the March 1997 issue of Electronics Now magazine. The circuit is applicable to any operational amplifier with a dual power source.
This stethoscope or hearing aid amplifier has excellent gain. It was found in Popular Electronics from...
Found in Fairchild documentation from the 90s, this circuit generates signals with the...
This configuration, widely used in our articles and on this website, uses a 555 to control a relay...