This grounding test circuit was found in an American 80's documentation. The circuit is for the 110 V power grid but can be changed to the 220 V power grid.
This circuit is from a 1976 technical documentation, providing a high input impedance with low...
We found this circuit that uses a thermistor as a sensor from the 1991 Electronics Experimenter Handbook....
This circuit was found in a PE Hobbyst Handbook from 1991. It turns on an LED only that...