Relays are switches that open and close circuits electromechanically or electronically. Relays control one electrical circuit by opening and closing contacts in another circuit. Source. It uses electromagnetism to convert small electrical stimuli into larger currents. These conversions occur when electrical inputs activate electromagnets to either form or break existing circuits. Source #2.
The example above depicts the workflow of the relay. In the circuit, we have an arduino uno (The microcontroller), a relay, and an electrical lock. The relay in this circuit controls when the electricity reaches the lock or not, therefore, controlling the locking mechanisms of the lock.
The relay is an essential component in the pizza customizer project as it main purpose is to control when the pizza dough drop/print. Also, the relay has another significant role in maintaining stability of electricity in the project (prevents overly high supply of power that can lead to damage to the electrical components).
Connect Wires to the relay.
weld the relay's wires to the arduino and pumb's wires using welding machine.
Use a tape to ensure the stability of the circuit.
Connect everything
And Done
Where all the electrical components reside.