This low frequency oscillator circuit was found in an Electronic Design from the 90s. The transistors are common types, and the frequency is given by the crystal.
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....