Using the 741 this basic circuit was found in the November 1973 Radio Electronics magazine. The power supply must be symmetrical. The components can be recalculated for other frequencies.
We found this circuit in an old documentation from the 70s, but it can be assembled with more...
This circuit controls a fan in the car, according to the temperature, activating it automatically when the...
This circuit was obtained from a 1967 General Electric documentation. The circuit makes use of...