What Is This ?

Answer :
Timer Relay
What is a relay?

Relays are electrically operated switches that allow one electrical circuit to control one or more other circuits by opening and closing its contacts in response to energizing or de-energizing its coil.

Relays are widely used to switch starting coils, heating elements, pilot lights and audible alarms. In addition to dishwashers, refrigerators, heating and air conditioning systems, relays control the operation of machine tools, industrial assembly lines and commercial equipment.

Protective relays can prevent equipment damage by detecting electrical abnormalities, including overcurrent, undercurrent, overloads and reverse currents.

How a relay works

A relay involves two circuits: the energizing circuit and the contact circuit. The coil is on the energizing side and the relay contacts are on the contact side.

When a relay coil is energized, current flowing through the coil creates a magnetic field. Whether in an AC or DC unit, the basic function remains the same – the magnetic coil attracts a ferrous plate that is part of the armature.

One end of the armature is attached to the metal frame, which is formed so that the armature can pivot while the other end opens and closes the contacts.
What is a timer?

A timing relay is a simple form of time-based control, allowing the user to open or close the contacts based on a specified timing function.

They can be designed, for example, with a set of selector switches, which can easily be set to a specific function and time, thereby reducing the number of product variations required.