Relays ACDelco

The relays use the electromagnetic principle to act as electrical switches. Relays are as switches commanded remotely, usually by a control module.

A relay consists of a coil with its core and one or more sets of contacts, one of which is fixed and the other movable.

The movable contact is maintained in its original position by a spring and that position is changed by the action of the magnetic field occurs around the coil when energized.

When a current is applied to the coil of a relay, a magnetic field is formed around the spool, it attracts the movable contact by changing his position to close or open the circuit. At the time that it stops applying current to the coil, the magnetic field disappears and the movable contact returns to its original position.

The relays used a small amount of current to control a greater amount of current.

The contacts of a relay can be normally open or closed.

These terms use the abbreviations "NO", which usually means open, and "NC" whose meanings are often closed.