This circuit with the NE602 was found in the February 1997 Electronics Now magazine. The NE602 integrated circuit is not very common these days.
The filter shown in the figure, using only an operational amplifier, is characterized by allowing 1...
Found in a 90s American documentation, this circuit can be used as a shield, just change the...
Found in a Philips' 1968 documentation, this circuit is slightly different from the previous one. The...