Using an operational amplifier of the time, this circuit was obtained from a 90s Radio Electronics. The circuit covers the frequency range from 2 Hz to 20 kHz.
This circuit, from a 2001 documentation, appears elsewhere on this site. Its purpose is to obtain a...
This circuit is from an old Elektor using components that are not currently common. The circuit is...
Found in a 1968 US publication, this circuit produces a delayed pulse with the negative transition...