Archives For Relay interface

Relay interface on I/O ports

February 23, 2011 — 1 Comment

When a current flows through the coil, the resulting magnetic field attracts an armature that is mechanically linked to a moving contact.  The movement either makes or breaks a connection with a fixed contact.   When the current to the coil is switched off, the armature is returned by a force approximately half as strong as the magnetic force to its relaxed position.  Usually this is a spring, but the gravity is also used commonly in industrial motor starters. Continue Reading…