This interesting sensor for RF signals was found in an article in the June 1989 Radio Electronics magazine. It is a field strength meter with an LED bargraph indicator.
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...