Relays are an electromechanical device used to control switching in an electrical circuit. A relay consists of an electromagnetic coil with a switching contact or several contacts, a magnetic core and one or more sets of connection terminals.
Relays are used to switch a large current in a power circuit using a small current in a signal or control circuit. This means that the power current in the electrical circuit can be controlled by turning it on or off by a switching operation in the circuit.
Relays are used for many applications. For example, electrical devices such as the voltage regulator of a car charger, a home air conditioning system, or an electric motor control the switching process using relays.
Relays are also widely used in industrial automation and control systems. PLCs (Programmable Logic Controllers) and SCADA (Supervisory Control and Data Acquisition) systems provide control of relays. Relays are used in industrial control systems to provide precise and reliable switching.