What is the working principle of a relay?
1 Answers
Working principle of automotive relays: When the relay operates, the electromagnet is energized, attracting the armature to make contacts D and E touch, thus closing the working circuit. When the electromagnet is de-energized, it loses its magnetism, and the spring pulls the armature up, cutting off the working circuit. Therefore, a relay is essentially a switch that uses an electromagnet to control the opening and closing of a working circuit. Extension: 1. A relay, also known as an electrical relay, is an electronic control device. It consists of a control system (also called the input circuit) and a controlled system (also called the output circuit), commonly used in automatic control circuits. Essentially, it is an "automatic switch" that uses a smaller current to control a larger one. Thus, it plays roles such as automatic regulation, safety protection, and circuit switching in electrical circuits. 2. The relay coil is represented by a rectangular box symbol in circuit diagrams. If the relay has two coils, two parallel rectangular boxes are drawn. The relay's text symbol "J" is also marked inside or beside the rectangular box. 3. Since a relay consists of two parts—the coil and the contact group—the graphical symbol of a relay in a circuit diagram also includes these two parts: a rectangular box represents the coil, and a set of contact symbols represents the contact group. When the circuit is simple with few contacts, the contact group is often drawn directly on one side of the coil box. This method is called the centralized representation method.
