We found this circuit in an old American documentation, but the circuit can still be assembled with ease as the used components are still available. MOSFETs admit equivalents.
We found this circuit at Modern Electronics in January 1991. The magazine no longer exists, but...
Found in a 90's EDN, this circuit can be used as a shield. The components depend on the MOSFETs...
This circuit will trigger an audible warning signal after the end of the pre-programmed timing. Using...