In modern automobiles, the reliability and safety of electrical systems are crucial, and automotive relays, as an integral part of these systems, play an indispensable role. With the ongoing development of automotive electrification and automation, the application range of automotive relays continues to expand, and their design and technology are continuously advancing. This article will provide a detailed introduction to automotive relays, including their definition, working principle, characteristics and advantages, applications, and more.

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I. What are Automotive Relays?

An automotive relay is an automated switch device typically used to control high-current circuits with a low-current control circuit. The most commonly used type in the automotive industry is the electromechanical-operated switch. They are found in all types of vehicles — cars, trucks, vans, trailers, and boats. These relays use an electromagnetic device to mechanically manipulate switches to open or close circuits. The most commonly used relays in the automotive industry are small cube-shaped units called standard or mini relays. The primary function of a relay is to use electromagnetic force to open or close contacts for circuit switching.

II. Working Principle

The working principle of an automotive relay is based on electromagnetic induction. When current flows through the relay's coil, it creates a magnetic field that moves the metal contacts to either close or open. Simply put, a relay controls high-power currents by switching them with low-power control currents. Typically, a relay has two main components: control contacts (low-current circuit) and load contacts (high-current circuit).

Common types of relays include Normally Open (NO) and Normally Closed (NC) relays:

Normally Open (NO) Relay: The contacts are open when no current flows. When powered, the contacts close, allowing current to flow.

Normally Closed (NC) Relay: The contacts are closed when no current flows. When powered, the contacts open, stopping the current flow.

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