We found this circuit in the Linear Applications Handbook of the National Semiconductor of 1994. The circuit can be adapted to use other operational amplifiers and the power supply must be symmetrical.
November 2016 - Already available from Mouser Electronics on Texas Instruments' new DS280BR820...
This circuit generates a pulsed tone whose frequency depends on C2 and whose flashing depends on...
The presented circuit is suggested by National Semicondictor in its 1994 Linear Applications...