In the complex electrical system of an automobile, automotive relays play an indispensable and critical role despite their small size. Today, MobikeChip will bring you an in-depth understanding of what an automotive relay is, and unveil its mysterious veil. 

The basic definition and working principle of automotive relay 

Automotive relay is essentially an electronic control device, which utilizes the principle of electromagnetic induction to realize the control of small current to large current, just like an intelligent switch, playing the role of signal conversion and circuit control in the automotive electrical system.   

Its core working principle is based on the role of electromagnetic force. When the coil of the automotive relay is energized, a strong magnetic field is generated, which attracts the armature inside the relay to move. The movement of the armature leads to the closing or breaking of the contacts, thus controlling the on-off of the circuit connected to it. For example, in the starting circuit of a car, when the driver turns the key to start the car, the ignition switch sends a small current signal to the coil of the starter relay. The coil of the relay is energized to produce a magnetic field, attracting the armature to make the contacts closed, then the large current can flow through the relay to the starter motor, driving the engine to start. This way of controlling large current through small current not only improves the safety of circuit control, but also effectively protects the car's electrical equipment from the impact of high current.  

The structure of the automotive relay analysis

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(A) Electromagnetic system 

Electromagnetic system is one of the core components of automotive relay, which is mainly composed of coil, core and armature. The coil is the key to generate a magnetic field, when the current passes through the coil, it will form a magnetic field around the iron core. The iron core, on the other hand, serves to enhance the strength of the magnetic field, making it more concentrated. Under the action of the magnetic field, the armature can produce mechanical movement to realize the opening and closing action of the contact.

(B) Contact system

The contact system is responsible for controlling the on-off of the circuit. It is usually composed of static contacts and moving contacts, moving contacts and armature connected. When the armature is moved by the magnetic field, the movable contact will contact or separate from the static contact, thus realizing the on or off of the circuit. The material and design of the contacts are crucial to the performance of the relay. High-quality contact material ensures good electrical conductivity and abrasion resistance, and ensures that the relay can still work stably and reliably during frequent opening and closing operations.

(C) Shell and pins

The shell of the automotive relay plays a role in protecting the internal components, but also prevents dust, moisture and other impurities from entering and affecting the performance of the relay. The shell is generally made of insulating materials, with good sealing and mechanical strength. The pins are the interface between the relay and the automotive circuit, through which the relay can receive control signals and control the main circuit. The design of the pins needs to ensure the firmness and reliability of the connection with the circuit to guarantee the stability of the electrical connection. 

Classification and application scenarios of automotive relays

(A) Classification according to control mode

Automotive relays can be categorized into electromagnetic relays, solid state relays, etc. according to the control method. Electromagnetic relays are the most common type and are widely used in various circuits of automobiles, such as starting circuits, lighting circuits, horn circuits, etc. Solid-state relays, on the other hand, utilize semiconductor components to realize circuit control. Solid state relays use semiconductor components to realize the control of the circuit, with no contact, fast response speed, long life and other advantages, commonly used in some of the reliability and control precision requirements of higher occasions, such as automotive electronic control system in the engine management system, anti-lock braking system (ABS) and so on.   

(B) Classification by Functional Purpose

From the functional use, automotive relays can be divided into starter relays, light relays, horn relays, wiper relays and so on. The starter relay is used to control the current of the starter motor to ensure that the engine can start smoothly; the light relay is responsible for controlling the headlights, turn signals, brake lights, and other lights on and off, to ensure driving safety; the horn relay controls the circuit of the horn, so that drivers can send warning signals by pressing the horn; wiper relay is used to control the work of the wipers, adjusting the speed and frequency of wipers according to different weather conditions. and frequency according to different weather conditions.

The importance of automotive relays

Automotive relays have irreplaceable importance in the automotive electrical system. It can realize the control of high voltage and high current by low voltage and small current, and effectively protect the electrical equipment and control system of the car. At the same time, the rapid response characteristics of the relay can ensure that the car in a variety of working conditions, the electrical system can quickly respond to protect the normal operation of the vehicle. For example, in the event of emergency braking, the brake light relay can respond quickly to illuminate the brake lights to alert the vehicle behind and avoid rear-end accidents.  

At MobikeChip, we are committed to providing high-quality relay products and professional technical support for the automotive electronics field. Knowing about automotive relays will help you better understand the working principle of automotive electrical system and make more informed decisions on automotive repair and modification. If you have any questions about automotive relay selection, application or other electronic components related issues, please feel free to visit MobikeChip website, our professional team will be happy to serve you. 

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