This third-order Butterworth filter was found in American documentation from the 1980s. Formulas for component calculations are attached to the diagram.
This circuit was published in an article in Electronics Now magazine in October 1995. The circuit...
This circuit was found in a 1926 German publication. It is a crystal or galena (D) receiver. The...
With this configuration, greater power can be obtained from an operational amplifier, thanks to...