When the relay is used to control high-powered equipment, it can switch with a low-powered signal. A relay is essentially an intermediate device that enables us to turn the circuit on or off from a distance. General-purpose relay forms an important component of any system that needs switching between multiple circuits or control high-power loads.
What is a general purpose relay?
A general relay is an electrical switch that opens or closes a circuit through an electrical signal and is usually used for automation and control purposes. It is called "general relay" because it has a wide range of applicability and can be applied in many industries such as household appliances, industrial machinery and automotive systems. These relays can handle a variety of current and voltage loads, enabling them to control the circuit in many different environments.
How does the general relay work?
The working principle of general relay is relatively simple, but it is very efficient. The relay controls the opening and closing of switches (or multiple switches) through electromagnets. When the current passes through the coil of the relay, the switch of the relay changes.
The working principle of the relay is to use electromagnet to open or close the switch. When the switch is closed, the circuit is connected and the current can flow. When the switch is open, the circuit is disconnected and the current cannot flow.
General purpose relays can be used to control a variety of equipment, including motors, lights, and pumps. They are usually used in applications that require switching a small amount of current, such as home appliances, automotive electronics, and office equipment.
Components of general relay
The general relay contains several key components to ensure its normal operation:
Coil: when the current passes through the coil, a magnetic field is generated.
Contact: these conductive parts will open and close at appropriate time to control the flow of current. Common contact types include normally open (no) and normally closed (NC) contacts.
Transmission core: a movable part that moves under the action of a magnetic field, thereby changing the state of the contact.
Spring: ensure that when the current is cut off, the drive iron core can return to the original position to help the relay reset.
Housing/frame: protect relay internal components from dust and mechanical damage.
Types of general purpose relays
Electromagnetic relay: the most common type of relay, which drives the drive core through the magnetic field generated by the coil and realizes switch control. Ideal for general purpose applications.
Solid state relay: unlike electromagnetic relay, solid state relay (SSR) has no moving parts, but uses semiconductor to perform switching function. Solid state relays provide faster response, lower noise and higher durability.
Thermal relay: this relay is used for overload protection. The bimetal sheet bends after heating, causing the contact to open and protecting the circuit from overcurrent. It is mainly used for motor protection.
Common application of general relay
Household appliances: for example, in refrigerators, washing machines and air conditioners, relays are used to control motors, heating elements and lighting.
Industrial machinery: Relay plays a very important role in controlling equipment such as conveyor belts, elevators, and robots. They can automate mechanical operation and reduce manual operation.
Automotive Industry: used in vehicles to control lights, and air conditioners. These relays switch high-powered components and, therefore, protect sensitive electric circuits.
Advantages of general relay
| Advantages | Description |
|---|
| Safety | Relays can isolate low-voltage control circuits from high-voltage circuits, providing extra protection and reducing the risk of electrical faults. |
| Cost-Effectiveness | Relays are typically low-cost components, with minimal maintenance costs, especially for devices that require frequent switching. |
| Versatility | General-purpose relays are used in various applications, including household appliances, industrial equipment, and automotive systems, meeting diverse needs. |
| Ease of Installation & Replacement | Relays have a simple structure, making installation and replacement easy, allowing for quick restoration of device functionality. |
| Automation Control | Relays can be used in automation control systems to automatically switch circuits, increasing operational efficiency and reducing manual intervention. |
| Long Lifespan | Especially solid-state relays, which have no moving parts, offering long service life and fewer mechanical failures. |
| Strong Interference Resistance | Relays can function reliably in environments with strong electrical interference, preventing system malfunctions. |
| Reduced Electrical Fire Risk | By automatically switching circuits, relays can prevent overload and short-circuit situations, thereby reducing the risk of electrical fires. |
| High Adaptability | Different types of relays can handle various voltage and current loads, effectively controlling different types of equipment and circuits. |
| Energy Efficiency | Using relays helps optimize control mechanisms, reducing energy waste and improving electricity usage efficiency. |
How to select suitable general relay
Selecting the appropriate relay requires knowing the required voltage and current ratings. As well as its relay type, I will list a general relay as follows. If you need, you can visit our relay category or consult us to provide you with detailed information
For example, this relay 24V 8 pin is universal. With reliable performance and compact structure, the power is 0.9W, the voltage is 24V, and the 8 pins can be well adapted to the socket to improve the adaptability and control ability
FAQ
Q: What is the working principle of general relay?
A: The relay attracts the transmission iron core through the electromagnet, so as to change the state of the contact and control the switch of the circuit.
Q: What is the difference between solid state relay and electromagnetic relay?
A: No moving parts in solid state relay and semiconductor to control current is used, faster response, no noise. Electromagnetic relay depends on an electromagnetic field that drives iron core for switching.
Q:What is the common application of a general-purpose relay?
Q:The general-purpose relay is applied in many household appliances, industrial machinery, and automotive industries to help people realize automatic control of a circuit.
Q: How to choose the relay properly?
A: The choice of the relay has to match load voltage and current capacity and has to agree with the relay type-such as an electromagnetic relay and solid-state relay.
Q: What's general relay service life?
A: It will generally be decided by service condition especially the contact wear and tear of the relay switch, usually, for solid state relays has long service life.
Q: How to keep the general relay?
A: The contacts and coils of the relays are to be checked time to time. The casing or housing of the relays must be cleaned and should not be dusty to avoid failures.
