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 was obtained from an 1974 Everyday Electronics magazine. The circuit is still current as...
This circuit triggers a remote doorbell when the phone rings. The circuit is for the 110 V mains...
The 4098 IC contains two monostable multivibrators in the same package. The basic configuration...