This filter was found in an old publication from 1977. The circuit must use a simple two-voltage source and the components can be changed for operation at other frequencies.
This circuit uses integrated 555 and an amplification step with transistors, as we can see in the...
This circuit uses components that are still common despite being from 1995 documentation. The circuit can...
This circuit was obtained from American documentation from the 1990s. The transformer can be a car...