| The electromagnetic relay
consists of a multi-turn coil, wound on an iron core, to form an electromagnet.
When the coil is energised, by passing current through it, the core becomes temporarily magnetised. The magnetised core attracts the iron armature. The armature is pivoted which causes it to operate one or more sets of contacts. When the coil is de-energised the armature and contacts are released. The coil can be energised
from a low power source such as a transistor while the contacts can switch
high powers such as the mains supply.
Relays can generate a very
high voltage across the coil when switched off.
|
| The springsets
(contacts) can be a mixture of n.o n.c and c.o.
Look at the page on switches to see how they can be used in circuits. Various coil operating voltages (ac and dc) are available. The actual contact points on the springsets are available for high current and low current operation. The REED RELAY has a much faster operation than the relays described above. |
