This circuit with zener diodes was found in documentation from the 90s. The zener diodes determine the lighting point of the LEDs. The circuit is for 12 V automotive batteries.
This ultra-low noise circuit was found in the May 1990 issue of Radio Electronics magazine. The...
The sophisticated signal tracker/follower with a JFET and integrated circuit 741 was found in a...
This two-transistor limiter for low-frequency signals was found in the May 1963 Radio Electronics...