This circuit was suggested by General Electric in a 1965 documentation. The circuit can be implemented with equivalent SCR.
This stage was found in a 1964 Electronic Design. The transistors are of the time and the shape of...
This circuit with the known PLL 567 can be found in other versions in this section and in this...
In this circuit, the LED Will blink in a presence of na áudio signal in the input. Gain is...