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.
The transducer of this circuit is a small ceramic capsule or crystal earpiece and the frequency given...
This circuit was found in an American documentation from 1968. The circuit generates ladder-shaped...
The circuit shown in the figure generates a rectangular signal whose frequency depends on C1. For...