Working Principle of Automobile Relay

Working principle of automotive relays

Relays are an automatic switching device consisting of an electromagnetic mechanism and at least one contact. Among them, the electromagnetic mechanism is responsible for generating a magnetic field, and the contact is responsible for switching when the electromagnetic mechanism is excited. Relays are widely used in circuits, which can expand the control ability of control circuits and realize functions such as automation and remote control. In automotive circuits, relays are also one of the indispensable components, which can ensure the safety and reliability of automotive circuits. This article will explain the working principle of automotive relays in detail.

1. Structure of relays

Relays are mainly composed of shells, electromagnets, contacts, springs, leads and other parts. Among them, the shell plays the role of fixing internal components, the electromagnet is the control part of the relay, the contacts are mainly used to control the on and off of the circuit, and the spring is an elastic component that ensures the up and down movement of the contacts on the electromagnet.

2. Working principle of relays

The work of automotive relays is to control the on and off of the contacts by means of electromagnetic attraction. Generally, the electromagnet is powered by an external power supply. In the absence of power, the electromagnet is in a power-off state, and the contacts are in a closed state. When

there is power input, the electromagnet will be excited by the current to form a magnetic field. The force of the magnetic field will cause the iron core on the electromagnet to move toward the contact, and also drive the elastic parts of the contact to move together. When the iron core and the contact are in contact, the contact is closed. In this way, a path is formed in the external circuit, and the current can flow.

When the power is disconnected, the electromagnetic magnetic field disappears, and the iron core also rebounds with the force of the spring, and the contact will open at the same time, and the circuit will be disconnected.

3. Types of relays

According to different usage scenarios, relays can be divided into multiple categories such as automotive relays, household appliance relays, and general relays. In the automotive field, relays can also be classified according to power level, operating temperature, structural form and other characteristics.

1. According to power level, it can be divided into: low-power relays, medium-power relays, high-power relays, etc.

2. According to operating temperature, it can be divided into: normal temperature relays, low-temperature relays, high-temperature relays, etc.

3. According to the structural form, it can be divided into: impact relays, sliding relays, etc.

4. Application of automotive relays

In automobiles, relays are widely used in various electrical control systems, such as headlight control, horn control, fan control, air conditioning control, engine start control, etc.

Taking the starting circuit as an example, a large current is required to start the car engine, and the current provided by the start button on the car key cannot meet this demand. Therefore, a relay is needed to amplify the current in the starting circuit. The relay in the starting circuit can convert the high-voltage current of the vehicle battery into a high-current low-voltage current for use when the engine is started.

5. Maintenance and care of relays

As the use time of the car increases, the relay may have problems such as circuit disconnection and electromagnet failure. Therefore, maintaining the car relay has also become a task that car owners must do.

1. Cleaning the relay: The relay will accumulate dust, dirt, etc. during use, and needs to be cleaned in time.

2. Check the voltage: When the relay is working normally, it needs to meet certain voltage requirements. If the voltage is too low, it will affect the normal operation of the relay.

3. Check the electromagnetic coil: The electromagnetic coil in the relay is a key component for the normal operation of the relay, and it is necessary to ensure that there is no short circuit and short circuit and repair it.

4. Regular replacement: Long-term use of the relay will cause wear and tear, and some aging relays need to be replaced regularly to ensure the safety and reliability of the car circuit.

In short, the car relay plays an important role in the car circuit. They can expand the control capability of the control circuit, realize functions such as automation and remote control, and at the same time ensure the safety and reliability of the automobile circuit. Understanding the working principle, classification and maintenance of automobile relays is also very beneficial for our normal driving and maintenance.