This circuit was found in the August 1996 Electronics Now magazine. The circuit is based on an operational circuit whose type determines the gains and limits for the frequency.
August 2017 - STMicroelectronics' new T850 switches with triacs up to 8 A can be obtained from...
This circuit is from the 1990 Motorola Linear Databook. The circuit can be applied to other...
Found in documentation from the 90s, this circuit makes use of components from the time....