This telephone circuit was found on a 90's EDN. It keeps a flashing LED to indicate that there was a call in your absence. The components admit equivalents.
This circuit is placed between the instrument pickup and the amplifier input. The same version can...
This circuit triggers on a lamp when the sensor (a metal plate us touched). Up to 100 W...
We obtained this circuit from a 1993 documentation. The circuit has current and voltage ranges that...