We found this circuit in a 1964 Electronic Design. It provides 0.5 V signals from 4 kHz subcarriers. Transistors are from the era.
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...