This circuit uses the LM2931 which is not a common component today. What it does is to activate a lamp causing it to blink at a frequency determined by the capacitor.
.
This circuit, which applies to configurations with triacs of the TIC series, was found in a...
This simple standing waveform (ROE or SWR) meter is used to adjust antenna matching with...
This circuit has a visual indication of activation and is suitable for people with hearing...