This useful project kit operates a relay switch depending on changes in the ambient light level. * The circuit uses an operational amplifier, used as comparator * Can be used as a light activated alarm sensor * Relay switch operates if light from a lamp, door, window, etc., is interrupted by a person's shadow * May also be used as twilight switch, automatically operating lamps, etc., at dusk * Kemo type B045 https://elecena.pl/product/27884825/kemo-b045-light-barrier-12v 2025-02-20 https://elecena.pl/product/27884825/kemo-b045-light-barrier-12v 2026-05-03