What is Relay?
{{about|electrical switches|running races|Relay race}} [[File:Electronic component relays.jpg|thumb|Relays]] A '''relay''' is an [[electromagnet]]ically operated [[switch]]. It was invented in the 19th century to make electric [[telegraph]] signals go farther. Nowadays relays control circuits with low-voltages. Many machines use them, including [[vehicle]]s and [[electronics]]. {{Commonscat|Relays}} [[Category:Electronics]] [[Category:Electronic components]] {{tech-stub}}