WHAT IS RELAY?
RELAYS are electromagnetic switches that provide to switch the great powers at low currents.
Mechanism of Relay
In general, relays consist of kernel, coil, contacts (short-circuit) and shaft.
Kernel : It is metal piece that copper wires are wrapped on and spool is passed. It is made from single piece ductile iron or siliceous metal sheet according to relay size. The reason of use of ductile iron is that it can loss its property of magnetism.
Coil : It is made from conductors which had been wrapped on the insulator material in the form of spool. Its conductor diameter and number of spir changes according to relay size and current which it will draw. When voltage is applied to the coil tips, coil gets electromagnet feature together with kernel. Thus, it provides the contact or separation of short-circuits pulling the palette across it.
Contacts (short-circuits): It is a collapsible piece current passing through each other while in contact with. The distortions, which are called “arc”,can be occurred during the closing at the contacts due to the electrical jump. To prevent this, the contacts are manufactured from excellent conductors ( noncorrosive). Normally, they can be open or close as production.
Shaft : It is the piece that relay parts are mounted on. Electrically isolated.
Working Principle of Relays
When the voltage is applied to the electromagnetic coil on the relay in accordance with relay type, coil gets magnetism feature. It does a switching mission connecting the one or more than one contacts with each other by pulling a metal palette opposed it.
