We found this circuit that can reach 50 MHz in the February 1997 Electronics Now magazine. The integrated circuits used are not very common today.
We found this variable regulator circuit in a Radio Electronics issue from July 1984. It is one of...
The MC4741 consists of a quadruple 741. The power supply must be symmetrical, and the resistors must be...
Suggested by Sprague in the 1980s documentation, this circuit can control three-phase AC motors....