This circuit was found in 1960s Radio Electronics. The circuit uses components from that time. The triac is according to the controlled load. The sensor is a common LDR.
This circuit, from a 1988 publication, consists of a timer that activates a relay at the end of a...
Found a documentation for PC from 1992, this circuit is indicated for the English power grid of...
This conventional window comparator configuration was found in an old documentation. It is valid...