This circuit was found in an Electronics World of 1968. The transistor can be any general purpose and the double T must be set to R3 for the desired effect.
This circuit with the known PLL 567 can be found in other versions in this section and in this...
ST Microelectronics STSPIN32F060x Three Phase 600V Controller This STMicroelectronics component...
The purpose of this circuit is to monitor the output voltage of a power supply. The under and over...