Both the operational amplifier and the diodes admit equivalents in this circuit suggested by National Semiconductor. The power source must be symmetrical, and the circuit curve resembles an ideal diode.
Below are two frequency filters for receivers using crystals. The crystals must have the frequency of...
This circuit was obtained in a 70s American documentation. The integrated circuits of the time are...
We found this circuit in a Radio Electronics from May 1959. The circuit uses a power relay and a...