Using the 741 this circuit can be adjusted to values between 1 Hz and 100 kHz. The power supply must be symmetrical. We found it in the Radio Electronics magazine of November 1973.
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...