Reed switches are very similar to
relays, besides a permanent magnet is used in place of a twine Coil. When the
magnet is a ways away the switch is open, however when the magnet is introduced
close to the transfer is closed as shown in figure. This switches are cheap can
be purchased easily. They are normally used for protection monitors and doorways
because they may be tougher to ’trick’ than other sensors.
With
this device the magnet is moved toward the reed transfer. Because it gets closer
the switch will near. This allows proximity detection without contact, however Calls
for that a separate magnet be attached to a shifting part.
