Found in Popular Electronics from the 90s, this circuit turns off an appliance at the end of the programmed time. The 12 V relay must have contacts according to the controlled current.
This simple alarm circuit was found in a 1998 documentation. When the sensors are activated, the...
This circuit was found in an old American documentation. The integrated circuit used is uncommon...
Found in a 90s Electronic Design, this suggestion to have a higher voltage in a fixed regulator...