This simple circuit for a common 110 V power grid was found in a 1980s American documentation. The circuit uses neon lamps as indicators.
This circuit is from 80s documentation, using still common CMOS components. The display is 7...
This circuit was obtained in an English magazine from 1979, but it can be easily assembled with...
Found in Electronics Now, this circuit generates signals for testing like a signal injector. The...