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.
The transistors of this circuit may be general purpose and the power supply comes from the TTL...
We found this circuit with the CMOS4046 in the August 1994 Electronics Now magazine. The circuit is...
This setting appears with variations at various points on this site. This is from a Motorola...