CHRIS KNAPTON / SCIENCE PHOTO LIBRARY CHRIS KNAPTON / SCIENCE PHOTO LIBRARY
Relay switches. View of three electrical relay switches. Relays switches use electric phenomenon (current changes, for example) to control the switching on or off of an independent electric phenomenon. These are electromagnetic relays. A wire (gold) is wound around a bar of metal, magnetising it when a current flows, and attracting a pivoted switch. This magnetic switch operates the independent feature in the circuit.
Model release not required. Property release not required.