This crystal-based circuit can generate accurate 50 or 60 Hz signals. The circuit is from a November 1998 Electronics Now magazine. The output signal consists of rectangular pulses.
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...