‍ ‍ ‍ ‍ ‍ ‍ Electromagnetic compatibility (EMC) definition

Refers to the ability of a device or system to operate in its electromagnetic environment to operate in a normal operation without causing unacceptable electromagnetic interference to any equipment in its environment. Therefore, EMC includes two requirements: on the one hand, the electromagnetic interference generated by the equipment in the equipment process cannot exceed a certain limit; on the other hand, the appliance has a certain degree of resistance to the electromagnetic interference existing in the environment. Disturbance, ie electromagnetic sensitivity.

EMC (ElectromagneticCompatibility)

Electromagnetic compatibility test equipment is defined in the International Electrotechnical Commission standard IEC for electromagnetic compatibility: the system or equipment can work normally in the electromagnetic environment, and will not cause interference to other systems and equipment.

EMC includes EMI (electromagnetic interference) and EMS (electromagnetic tolerance), the so-called EMI electromagnetic interference, electromagnetic interference scanning system is the electromagnetic noise generated by the machine itself in the process of performing its functions, which is not conducive to other systems; EMS refers to the ability of a machine to be unaffected by the surrounding electromagnetic environment while performing its intended function.

Electromagnetic compatibility (accommodation) A variety of electrical or electronic equipment in a complex space of the electromagnetic environment, with the specified safety factor to meet the normal working capacity of the design requirements. Also known as electromagnetic compatibility. Its meaning includes: 1 electronic system or equipment in the electromagnetic environment of each other; 2 electronic systems or equipment in the natural electromagnetic environment can work according to design requirements. If it is extended to the influence of electromagnetic fields on the ecological environment, the content of electromagnetic compatibility can be called environmental electromagnetics.

Electromagnetic compatibility research is gradually moving toward high frequency, high speed, high precision, high reliability, high sensitivity, high density (small size, large-scale integration), high power, small signal operation, and complexity. Need to develop gradually. In particular, the use of modern electronic technology in artificial earth satellites, automobiles, computers, communication equipment and submarines has made electromagnetic compatibility more prominent.

‍ ‍Content

All kinds of operating electrical equipment are related to each other and interact with each other in three ways: electromagnetic conduction, electromagnetic induction and electromagnetic radiation. Under certain conditions, it will cause interference, influence and harm to the running equipment and personnel.

The electromagnetic compatibility EMC discipline that emerged in the 1980s aims to study and solve this problem, mainly to study and solve the interference generation, propagation, reception, suppression mechanism and its corresponding measurement and measurement techniques, and based on this, The principle of technical and economic rationality, clearly stipulates the level of interference generated, the level of anti-interference and the restraining measures, so that the equipment in the same electromagnetic environment is compatible, and at the same time, it does not introduce any unallowable to any entity in the environment. Electromagnetic disturbance.

The institutes for testing and testing electromagnetic compatibility (including electromagnetic interference and electromagnetic resistance) include the Suzhou Electric Apparatus Research Institute, the Aerospace Environmental Reliability Test Center, and the Environmental Reliability and Electromagnetic Compatibility Test Center.

Internal interference refers to mutual interference between various components inside an electronic device, including the following:

(1) The interference caused by leakage of the working power supply through the distributed capacitance and insulation resistance of the line; (related to the operating frequency)

(2) The signal is coupled to each other through the impedance of the ground wire, the power source and the transmission wire, or the interference caused by the mutual inductance between the wires;

(3) Some components inside the equipment or system generate heat, which may affect the interference caused by the stability of the components themselves or other components;

(4) The magnetic field and electric field generated by high-power and high-voltage components affect the interference caused by other components through coupling.

External interference refers to interference from a line, device or system by factors other than electronic equipment or systems, including the following:

(1) External high voltage and power supply interfere with electronic circuits, equipment or systems through insulation leakage;

(2) External high-power equipment generates a strong magnetic field in space, and interferes with electronic circuits, equipment or systems through mutual inductance coupling;

(3) interference caused by space electromagnetic waves to electronic circuits or systems;

(4) The temperature of the working environment is unstable, causing interference caused by changes in internal circuit components of the electronic circuit, equipment or system;

(5) Equipment powered by industrial power grids and interference generated by power grid voltages through power transformers.

Rapid development of electromagnetic compatibility technology

Electromagnetic waves exist everywhere in the nearly 1,000-kilometer space from the surface of the Earth to the activities of satellites. Electricity and magnetism affect people's lives and production all the time. The wide application of electromagnetic energy makes the development of industrial technology change with each passing day. While electromagnetic energy creates enormous wealth for human beings, it also brings certain harms. It is called electromagnetic pollution. Studying electromagnetic pollution is an important branch of environmental protection. In the past, the interference that the radio communication device was subjected to was called electromagnetic interference, which indicated that the device was invaded by external interference. In fact, it also caused damage to other external devices, that is, it became a source of interference. Therefore, it is necessary to study the interference and interference resistance of the device at the same time, and pay attention to the compatibility between the organization and the device inside the device. With the development of science and technology, the increasingly widely adopted microelectronic technology and the gradual realization of electrification have formed a complex electromagnetic environment. Continuous research and resolution of the relationship between equipment and systems in the electromagnetic environment has promoted the rapid development of electromagnetic compatibility technology.

‍ ‍ Design Requirements

When performing EMC design:

1 Clear system electromagnetic compatibility indicators. The electromagnetic compatibility design includes the electromagnetic interference environment in which the system can maintain normal operation and the allowable indicators of the system to interfere with other systems.

2 On the basis of understanding the interference sources, interfered objects and interference paths of the system, these indicators are distributed to each sub-system, subsystem, circuit, component and device through theoretical analysis.

3According to the actual situation, take corresponding measures to suppress the interference source, eliminate the interference path, and improve the anti-interference ability of the circuit.

4 Through experiments to verify whether the original requirements have been met. If not, further measures are taken and the cycle is repeated until the original target is reached.

Electromagnetic interference source

Divided into two kinds of natural and artificial. Natural sources of interference mainly include various phenomena occurring in the atmosphere, such as lightning, snow, rain, hail, sandstorms and the like. Natural sources of interference also include cosmic noise from the sun and outer space, such as solar noise, interstellar noise, and galaxy noise. The sources of human interference are various, such as various signal transmitters, oscillators, motors, switches, relays, xenon lamps, fluorescent lamps, engine ignition systems, electric bells, electric heaters, arc welding machines, high-speed logic circuits, gate circuits, SCR inverters, gas rectifiers, corona discharges, various industrial, scientific and medical high-frequency equipment, urban noise, noise caused by electric railways, and nuclear electromagnetic pulses generated by nuclear explosions.

way for spreading

There are two types: conducted interference and radiated interference. The interference propagating along the conductor is called conducted interference, and its propagation modes are electrical coupling, magnetic coupling and electromagnetic coupling. Electromagnetic interference propagating through electromagnetic waves in space is called radiated interference, and its propagation modes include near-field inductive coupling and far-field radiation coupling. In addition, conducted and radiated interference may also exist simultaneously, resulting in composite interference.

Main research object

1 Various artificial noises, such as transmission line corona noise, car noise, contactor's own noise and noise caused by discharge when the conductor is turned on, electrical locomotive noise, urban noise, etc.

2 The impact of various utility equipment (transmission lines, communications, railways, highways, petroleum metal pipelines, etc.) in the shared corridor. 3

Reflection problems caused by large buildings such as super high-rise buildings, power lines, and iron towers.

4 The role of the electromagnetic environment in humans and various living things. These include power frequency fields such as strong wires, medium and short waves, and the effects of microwave electromagnetic radiation.

The effect of 5 nuclear electromagnetic pulses. Electromagnetic pulses generated by high-altitude nuclear explosions can destroy command, control, communications, computer and reporting systems on the ground.

6 SPECTEST technology. Its substance is a series of research work on information reception and protection from electromagnetic radiation and information leakage of information equipment.

7 Electronic device malfunction. In order to prevent malfunction, measures must be taken to improve the anti-interference ability of the equipment.

8 spectrum allocation and management. The radio spectrum is a limited resource, but it is not consumable. It must be managed scientifically and fully utilized.

9 electromagnetic compatibility and measurement.

10 natural influences, etc.

Compatibility measures

1 Use a perfect shield to prevent external radiation from entering the system, and to prevent the interference energy of the system from radiating outward. The shield should be kept in good condition, and the necessary doors, joints, vents and cable holes should be properly handled, and the shield should be reliably grounded.

2 Design a reasonable grounding system, the small signal, large signal and the circuit that generates the interference should be grounded as far as possible, and the grounding resistance should be as small as possible.

3 Using appropriate filtering techniques, the passband of the filter is properly selected to minimize leakage losses.

4 Using the limiting technique, the clipping level should be higher than the working level and should be limited in both directions.

5 Correctly select the connecting cable and wiring method, and replace the long cable with optical cable if necessary.

6 uses balanced differential circuits, shaping circuits, integration circuits and gating circuits.

7 system frequency allocation should be appropriate. When there are multiple main frequency signals working in a system, try to avoid the frequency of each signal and even avoid the resonant frequency of the other party.

8 All kinds of equipment in the shared corridor should maintain a large gauge when conditions permit, so as to reduce the mutual influence.

EMC design

Due to the increasing dependence of microcomputers, the extensive use of equipment complicates our electromagnetic environment, so external disturbances such as impulse noise, radiated electromagnetic fields, static electricity, lightning strikes, voltage changes, etc., cause malfunctions and even damage. Situations such as radio communications, radar, cell phones, etc. It often interferes with TV, and even causes malfunctions in the use of medical equipment, which affects the safety of flying.

Internationally, the immunity test for electronic, electrical and industrial equipment products has been paid more and more attention, and the integration of IEC (International Electrotechnical Commission) international standards has been adopted as the test standard. The European Community has taken the lead in formulating EMC prevention and control regulations, and comprehensively implemented the immunity test in 1996. .

Power supply

The three-phase input power supply is equipped with a noise filter (NoiseFilter) between the NFB (fuseless circuit breaker) and the transformer. The input line of this filter is as short as possible.

The power supply and high current wires are placed against the bottom of the electrical box and routed along the corners.

The switchgear power supply is equipped with a shield to prevent radiated emissions. The filter selector uses π or T to suppress wide-band noise, and the ferrite magnet suppresses RF noise.

Both ends of the power line are considered to be isolated and grounded to prevent the ground loop (GroundLoop) from forming a common impedance coupling (Common Impedance Coupling) to couple the noise to the signal line.

The power and signal lines should be isolated or separated as much as possible.

The power transformer should be Shielded and the enclosure must be well grounded.

Stranded wires are recommended for single-phase AC control lines.

It is recommended to use a twisted wire for wiring the DC conductor.

Avoid connecting the power supply to the signal cable to the same connector.

Signal line aspect

Signal input lines and output lines should be avoided to cause interference.

The remaining unused wires of CABLE should be grounded at one end to avoid forming an inductive loop.

The signal line near the power line is considered to be Twist.

Different types of signal lines are avoided to be mixed on one connector, and should be classified by category and grounded.

The input signal line and the output line should be avoided as much as possible on the same connector. If it cannot be avoided, the input and output signals should be staggered.

The low-sensitivity signal line with higher sensitivity can be isolated and shielded in addition to the stranded wire.

Analog signal aspect

Isolation lines are recommended for high frequency analog signals and pulse signal lines.

The high-frequency analog signal line adopts a coaxial isolation line, and the low-frequency analog signal line adopts a twisted line. If necessary, an isolation shield can be added, and a coaxial isolation line must not be used.

The mounting position of the connector must be cleaned, and the contact resistance of the connector and metal surface must be less than 2.5m ohms.

Analog circuit interference is dominated by waveform distortion, and the suppression method is mainly based on the characteristics selected by the filter, such as bandwidth and frequency response.

The analog signal line and the digital line must be perpendicular to each other.

Digital signal

Avoid using unisolated shielded wires to transmit digital signals. Multiple strands plus isolation lines should be used.

In addition to digital circuit interference, magnetic field interference is dominant, and isolation measures should be added.

Digital circuits are susceptible to high-energy electric field interference and must be isolated using isolation lines to prevent high-energy electric field 200V/m interference in the 1∼10MHz band as the best isolation option.

Digital circuits are mainly used to suppress adjacent circuit pulse and spike (Spikes) interference.

Digital circuit transmission avoids the use of wires that are too long and unisolated.

Circuit design

Interfering circuits, such as clocks, drivers, switched-mode power supplies ON and OFF, and oscillator-type control signals, should be shielded.

All types of PCB circuit design should use low-noise components as much as possible, and the relationship between noise changes and ambient temperature changes must be considered.

Ferritecore is suitable for high frequency filtering, but care must be taken to reduce the power loss through this coil.

Regulators must consider the suppression of common impedance coupling (CommonImpedanceCoupling) EMI problems between lines.

The smaller the output of the oscillator itself, the better. If a larger output is required, it should be amplified by the amplifier.

Power amplification should be isolated to prevent radiative emissions.

Electrolyte capacitors are suitable for removing high Ripple and Transient Voltage changes.

The interference of the power line has low voltage (or instantaneous power failure) overvoltage and surge. These interferences usually come from the action of the power switch, the moment of opening and closing of the heavy load, the operation of the power semiconductor, the blown fuse, the lightning induction, etc. .

The following items must be considered to suppress:

Use a power filter.

Proper power distribution.

The interfered device switches to another circuit.

Pack the electronic parts and filters appropriately.

Use an isolation transformer.

Device varistor.

AC electromagnetic contactor coils and solenoid valves must be connected to a spark eliminator.

The pyroelectric output side of the electromagnetic switch must be connected to a three-phase spark eliminator.

The DC relay coil is connected to the diode for reverse voltage protection.

The closer the spark eliminator is to the load side, the better.

The surge absorber is placed between the circuit switch and the noise filter, and between the line and the line, between the line and the ground, the surge can be effectively absorbed.

Electromagnetic interference

Electromagnetic interference is any electromagnetic phenomenon that degrades the performance of a device or system. The so-called electromagnetic sensitivity refers to the performance degradation of equipment or systems caused by electromagnetic interference.

Type of interference

Electromagnetic interference (Electromagnetic Interference), referred to as EMI, has both conducted and radiated interference. Conducted interference is mainly caused by interference signals generated by electronic devices through the conductive medium or the common power line. Radiated interference means that the interference signals generated by the electronic devices transmit the interference signals to another electrical network or electronic device through spatial coupling.

In order to prevent the electromagnetic interference generated by some electronic products from affecting or destroying the normal work of other electronic devices, governments or some international organizations have successively proposed or formulated some regulations or standards for electromagnetic interference of electronic products, and products complying with these regulations or standards. It can be said to have EMC (Electromagnetic Compatibility). EMC standards for electromagnetic compatibility are not constant, but are changing every day. This is also the means that governments or economic organizations often take to protect their own interests.

10.1 Measures for Prevention and Control of Electromagnetic Compatibility

The primary measure to suppress electromagnetic pollution is to find the source of pollution; the second is to judge the path of pollution intrusion, mainly in both conduction and radiation, the focus of work is to determine the amount of interference. Solving the problem of electromagnetic compatibility should start from the development stage of the product and run through the entire product or system development and production process. A large number of experiences at home and abroad have shown that the earlier attention to solving electromagnetic compatibility problems in the development and production of products or systems, the more manpower and material resources can be saved.

The key technology of electromagnetic compatibility design is the study of electromagnetic interference sources. Controlling electromagnetic emissions from electromagnetic interference sources is the cure method. Controlling the emission of an interference source, in addition to reducing the level of electromagnetic noise generated by the mechanism generated by the electromagnetic interference source, requires extensive application of shielding (including isolation), filtering, and grounding techniques.

The shielding mainly uses various conductive materials, is manufactured into various shells and is connected with the earth to cut off the electromagnetic noise propagation path formed by the electrostatic coupling, inductive coupling or alternating electromagnetic field coupling of the space. The isolation mainly uses relays, isolation transformers or photoelectrics. Devices such as isolators cut off electromagnetic noise in a conductive form of propagation, which is characterized by separating the grounding systems of the two parts of the circuit and cutting off the possibility of coupling through the impedance.

Filtering is a technique for processing electromagnetic noise in the frequency domain, providing a low-impedance path for electromagnetic noise to achieve the purpose of suppressing electromagnetic interference. For example, the power supply filter exhibits a high impedance to the 50 Hz power supply frequency and a low impedance to the electromagnetic noise spectrum.

Grounding includes grounding, signal grounding, and so on. The design of the grounding body, the arrangement of the ground wire, and the impedance of the grounding wire at various frequencies are not only related to the electrical safety of the product or system, but also related to electromagnetic compatibility and its measurement technology.

problem

In order for electromagnetic compatibility problems to occur in the system, there must be three factors, namely electromagnetic disturbance source, coupling path, and sensitive equipment. Therefore, in the face of electromagnetic compatibility problems, we must start from these three factors, the right medicine, eliminate one of the factors, can solve the electromagnetic compatibility problem.

11.1 Source of Harassment

The electromagnetic energy emitted by any form of natural or electrical energy device can cause harm to people or other creatures sharing the same environment, or cause electromagnetic hazard to other equipment, subsystems or systems, resulting in degradation or failure of performance, known as electromagnetic disturbance source. Generally speaking, electromagnetic interference sources fall into two categories: natural interference sources and human interference sources.

(1) Natural interference sources

It is mainly caused by the skylight noise of the atmosphere and the cosmic noise of the outer space of the earth. They are both an essential part of the Earth's electromagnetic environment and a source of interference that interferes with radio communications and space technology. Natural noise can interfere with the operation of satellites and spacecraft and can also interfere with the launch of ballistic launch vehicles.

(2) Human interference sources

It is the electromagnetic energy interference generated by organic electricity or other artificial devices. Some of them are devices specially used to emit electromagnetic energy, such as radio equipment such as radio, television, communication, radar and navigation, which are called intentional emission interference sources. The other part is the launch of electromagnetic energy with the completion of its own functions, such as transportation vehicles, overhead transmission lines, lighting equipment, electric machinery, household appliances, industrial and medical RF equipment. This part has therefore become an unintentional source of interference.

11.2 Coupling approach

That is, the path or medium through which the disturbance is transmitted. Electromagnetic interference propagation methods are generally divided into two types: conductive coupling and radiation coupling.

Any electromagnetic interference must occur in the transmission and transmission path (or transmission channel) of the interference energy. It is generally believed that there are two ways to transmit electromagnetic interference: one is a conductive transmission method; the other is a radiation transmission method. Therefore, from the perspective of the interfered sensor, the interference coupling can be divided into two types: conduction coupling and radiation coupling.

(1) Conductive coupling

Conducted transmission must have a complete circuit connection between the interference source and the sensor, and the interference signal is transmitted to the sensor along this connection circuit, causing interference. This transmission circuit can include wires, conductive components of the device, power supply, common impedance, ground plane, resistors, inductors, capacitors, and mutual inductance components.

(two) radiation coupling

Radiation transmission is transmitted through the medium in the form of electromagnetic waves, and the interference energy is emitted to the surrounding space according to the law of the electromagnetic field. There are three kinds of common radiation coupling: 1. The electromagnetic wave emitted by the antenna is accidentally accepted by the antenna, which is called antenna-to-antenna coupling; 2. The space electromagnetic field is coupled by wire induction, called field-to-line coupling; 3. two High frequency signal sensing between parallel wires is called inductive coupling of wire-to-wire.

In actual engineering, interference between two devices usually involves coupling of many ways. Because of the simultaneous existence of multiple ways of coupling, repeated cross-coupling, and interference together, electromagnetic interference becomes difficult to control.

11.3 sensitive equipment

A sensitive device (Victim) is a device, device, subsystem or device that can be harmed by electromagnetic energy emitted by an electromagnetic disturbance source, and an electromagnetic hazard that causes degradation or failure of performance. system. Many devices, devices, subsystems, or systems are both sources of electromagnetic disturbances and sensitive devices. A sensitive device is a general term for an interfering object. It can be a small component or a circuit board component, or it can be a single powered device or even a large system.

the term

(1) Equipment refers to any electrical, electronic or electromechanical device that operates as a stand-alone unit and performs a single function.

(2) System refers to "a number of equipment, sub-systems, full-time personnel and technical combinations that can perform or guarantee work tasks."

(3) Electromagnetic environment (electromagnetic environment) The sum of all electromagnetic phenomena existing in a given place.

"A given place" is "space", "all electromagnetic phenomena" includes all "time" and all "spectrum".

EMC: (Electromagneticcompatibility) electromagnetic compatibility

EMI: (Electromagnetic interference) electromagnetic interference

EMS: (ElectromagneticSusceptibility) electromagnetic sensitivity

RE: (Radiatedemission) Radiation disturbance (commonly known as: electromagnetic radiation, radiation emission)

CE: (Conductedemission) conducted disturbance (commonly known as: conducted emission)

CS: (ConductedSusceptibility) conducted disturbance immunity

RS: (RadiatedSusceptibility) Radio Frequency Electromagnetic Field Radiation Immunity

ESD: (Electrostaticdischarge) electrostatic discharge

EFT/Burst: (Electricalfasttransientburst) Electrical Fast Transient Burst

RFI: (RadioFrequencyInterfernce) radio frequency interference

ISM: (Industrial Scientific Medical) industrial, scientific, medical RF equipment

Electromagnetic Compatibility

Electromagnetic compatibility (EMC) is divided into electromagnetic interference (EMI) and electromagnetic resistance (EMS), and all electronic products must comply with the general requirements of electromagnetic compatibility.

Electromagnetic compatibility issues in the electronic, electrical, information, communications and other products continue to use high-tech to promote innovation, in addition to users demand communication quality, but also under the government's active development of relevant regulations to control, more prominent electromagnetic compatibility The importance and urgency of related issues. For example, Europe has stepped up post-market testing of imported products, causing many card closures to occur.

Until now, the technology to determine whether a product will affect the function of another product is still not a precise science, and because the product portfolio is too complex, it is impossible for the certification body to detect each product portfolio, so the relevant supervisor The authorities do not take an attitude of strict control. Figure 1 shows the standards set by the International Special Committee on Radio Interference (CISPR) for electromagnetic interference emitted by each country. CISPR is a special committee of the International Electrotechnical Commission (IEC).

As the world's two major consumer electronics markets, the US and European certification standards are not the same. In short, the United States only requires electromagnetic interference, while Europe also requires electromagnetic compatibility.

US FCC standard certification is harsh

When a current passes through the circuit, an electromagnetic field is generated. This electromagnetic field is emitted outward from the device circuit and its intensity depends on the frequency and magnitude of the current. Any by-products other than those required for electronic circuits are referred to as electromagnetic interference.

At present, most of the electromagnetic interferences of various advanced electronic products on the market come from high-frequency digital signals. The higher the signal frequency, the more electromagnetic interference is generated. Since the Federal Communications Commission (FCC) and other regulatory agencies strictly stipulate the upper limit of electromagnetic interference for each electronic product to ensure that electronic products do not interfere with each other, this situation will cause serious problems, as long as the product is intended to be sold to the United States, it must be Comply with the electromagnetic interference certification standards set by the FCC.

To sell electronic products in the United States, the FCC requires that electromagnetic interference be measured in a specific environment within the electromagnetic interference range. These products must have electromagnetic radiation far below a certain value in a specific frequency band.

The FCC provides two levels of radiation levels: Class A and Class B (Table 2). Class A products are digital products for commercial, industrial and work environments, not for everyday or domestic use; Class B digital products are not only suitable for home use, but also for use in other environments. In general, the B-level standard is more stringent than the A-level.

Table 1 FCC rules for Class A and Class B

Table 1 lists the contents of the A-grade product with a voltage level of 10 meters and a B-level voltage level of 3 meters. Assuming the DUT exceeds these limits, the excess energy must fall below the limits listed in Table 2. It is very dangerous if the electromagnetic interference energy is just below the specified limit, because this energy will increase slightly due to changes in the manufacturing process and the environment. In particular, it is very difficult to reduce the excess interference frequency in the fifth harmonic. If the enterprise forcibly increases the safety limit to 4dB, it will make the problem worse.

Ten questions to be aware of through FCC certification

Experts concluded that failure to pass FCC certification is usually caused by the following ten factors:

The FCC requirements are ignored or underestimated during the initial design phase;

Choose the fastest component and the highest frequency rate;

Use single or double layer boards instead of multilayer printed circuit board (PCB) boards;

Radiation problems are not considered in frequency wiring;

Not enough bypass capacitors are used;

Use an unshielded cable;

Use a plastic connector;

No ceramic iron magnets were used in the cable design;

No integrated circuit filter;

The rack is not properly shielded.

European ESTI standards require simultaneous electromagnetic interference and electromagnetic withstand

In Europe, the electromagnetic compatibility regulations for telecommunications products can be found in the documents published by the European Telecommunications Standards Institute (ETSI). ETSI is a non-profit organization responsible for the development of European telecommunications standards, and its standards are used by many countries, such as China.

The general provisions on electromagnetic compatibility in the documents promulgated by ETSI are EN301489-1. In addition to the electromagnetic interference regulations, there are also provisions for electromagnetic resistance, mainly to test whether the products can work normally under various electromagnetic interference environments. The test content includes:

RadioFrequencyElectromagneTIeField: mainly to simulate the effects of radio waves and radio signals on products;

Electrostatic test (ElectrostatieDiseharge): mainly to simulate the impact of static electricity or hand tools on the human body;

FastTransients (commONMode): The purpose of this test is to verify the tolerance of the product's power line, signal line (control line) subjected to repeated rapid transient pulses;

RadioFrequency (commonMode): This test is to verify the noise tolerance of the product to the RF generator through the power line;

VoltageDIPs and Interuptions: This test is to verify the tolerance of the product through the power line simulation voltage changes;

Surger resistance test (Surges): This test is to withstand the transient overvoltage/current surge of the switch or lightning strike on the power line or communication port under the operating condition of the product.

Electromagnetic compatibility test equipment

technical standard

13.1 Foreign standards

EN55014-1 electromagnetic interference

EN55014-2 electromagnetic immunity

EN60555-2/EN61000-3-2 power supply harmonic detection

EN60555-3/EN61000-3-3 voltage flicker detection

EN61000-4-2 (ESD) Electrostatic Discharge Anti-interference Detection

EN61000-4-3 Electrostatic discharge anti-interference detection

EN61000-4-4 (EFT/B) electrical fast pulse group anti-interference detection

EN61000-4-5 (Surge) lightning strike anti-interference detection

EN61000-4-6 (CS) conducted anti-interference detection

EN61000-4-8 power frequency magnetic field anti-interference detection

EN61000-4-11 (V.Dips) voltage transient anti-interference detection

EN61000-4-12 oscillating wave surge

EN61000-4-13 (Harmonic & interharmonics) harmonic, interharmonic anti-jamming

13.2 Domestic standards

CISPR15:2005 Limits and methods of measurement of radio disturbance characteristics for electrical lighting and similar equipment

General requirements for immunity of GB/T19287 telecommunication equipment

Electromagnetic information security requirements and measurement methods for YD/T1536.1 telecommunication equipment

YD/T1312 wireless communication equipment electromagnetic compatibility requirements and measurement methods

GB1565 city radio noise measurement method

GB6833 electronic measuring instrument electromagnetic compatibility test specification

GB/T17626 electromagnetic compatibility test and measurement technology

GB/T12572-2008 General requirements and measurement methods for radio transmitting equipment parameters

Mutual interference limitation and coexistence requirements and test methods for radio communication equipment in the GB/T26256-2010 2.4 GHz band

GB/T21646-2008400MHz frequency band simulation public wireless walkie-talkie technical specifications and measurement methods

GB8702-1988 Electromagnetic Radiation Protection Regulations

GB9175-88 environmental electromagnetic wave health standard

GB12638-90 microwave and ultrashort wave communication equipment radiation safety requirements