Talking about the basic knowledge of relays and application fields

The basics of the relay are as follows:

In communications equipment, automatic devices, household appliances, automotive electronics, and other electrical circuits where the need for conversion, you can use the relay. Because the relay is composed of a coil and a contact group, the relay's graphic symbol in the circuit diagram also includes two parts: a rectangular box indicates a coil, and a group of contact symbols indicates a contact combination. When the contact is not much simple circuit, the contact group is often drawn directly on the side of the coil box, this method is called concentrated representation.

Relays use a very wide area, its environmental conditions, technical requirements vary greatly. Is the same field of use of different occasions, the requirements are not the same. Here are some examples of commonly used areas for your reference as a reference:

First, industrial control relays

In industrial control, the main control functions by the universal AC relay to complete. The relay is usually driven by a push button or limit switch. The relay contacts control solenoid valves, larger start-up motors and indicators. The voltage is generally 24VDC, 220VAC.

Digital control has expanded the relay application. Profile milling and coordinate boring are programmed by data and the signals are fed into the machine controller, memory unit and other logic elements to control 2 to 5 axes of the coordinate servo motor. With this automatic control method is easy to control drilling, hex lathes, lathes and automatic calibration machine.

Digital control systems require relays to adapt to low-level signals, medium sensitivity, fast motion and high switching reliability.

Industrial machinery installation of environmental conditions must be considered, running industrial machinery and nearby equipment is always some of the impact, vibration transmitted to the control cabinet; there is the possibility of splashing cutting coolant. Equipment manufacturers usually take some protective measures on the control components, but these adverse environmental conditions should still be considered when selecting and designing relays.

Second, the automotive sector

The automotive industry is using relays more and more widely. More common are: start the motor start relay, horn relay, motor or generator circuit breaker relays, charging voltage and current regulation relays, change the signal flash relay, light brightness control relays and air conditioning control relays, sliding door automatic opening and closing control relays ; Window lift control relay.

The car's power supply is now more 12V, the coil voltage is designed for 12V. Because it is a battery-powered, voltage instability; to poor environmental conditions, suction voltage V ≤ 60% VH (fixed operating voltage); coil over-voltage allows up to 1.5VH. Coil power consumption is larger, generally 1.6 ~ 2W, temperature rise higher.

Third, household appliances

1, air conditioning

The relays are mainly used to control the compressor motor, the fan motor and the cooling pump motor to perform the relevant control functions. Home compressor motor, the power is generally 1 to 3 horsepower; fan motor and cooling pump motor 1/2 to 2 hp.

As the load starts momentarily, a large inrush current occurs, about 6 times the full load operating current. Compressor motor to reach full speed takes a long time, which poses a serious threat to the relay contacts, therefore, requires the relay's load capacity to leave sufficient margin; requires as much as possible to eliminate the relay pull-in contact bounce; require the relay to release Fast, minimize contact bounce.

2, household appliances in this area, relays for washing machines, microwave ovens, electric heaters and so on.

Relay contact load: large up to 220V, 5000W heater (or 1 horsepower motor) load, as small as the drive solenoid, other relay coils, lights and other small loads. Relays are expected to have a life expectancy of 5 to 10 years. This means that the electrical life of the relay requires 105 times to 2 × 105 times.

Shenzhen Xin Ai Fu Electronics Co., Ltd., professional sales of general relays for more than 10 years. In this era of rapid development and competition, customers need more than just product suppliers, but high-quality and stable strategic partners, providing customers with a full range of products and services and solutions, which requires a professional and efficient team of qualified personnel, stable And competitive channels for the integration of goods, a solid financial strength, in order to achieve this goal, Xin Aifu Electronics Products Division after more than 10 years of professional temper and build came into existence in the relay industry, is now providing customers with great Competitive products and services.