This circuit lets through the 300 Hz to 3kHz range that corresponds to the human voice. We found it in the Radio Electronics magazine of February 1990. The circuit uses both parts of the LM381.
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...