This 1 kHz circuit was found in American documentation from the 90s. The original operational amplifier consists of a double 741 at the time. The power supply must be symmetrical.
This circuit with a supply voltage of only 2.5 V was found in a 2005 Linear Technology...
This circuit was obtained from old documentation and has a very simple 6 or 12 V configuration...
This is one of the many applications of the 555. We found it in the November 1992 Radio...