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.
Found in an old documentation about neon lamps, this circuit has the frequency basically...
This simple standing waveform (ROE or SWR) meter is used to adjust antenna matching with...
This is the traditional configuration of a high-pass filter with an operational amplifier, such as...