Comprehensive interpretation of the characteristics and standards of LED lamps

This article analyzes the characteristics and current problems of LED lamps and lanterns based on the definition of LED lamps and lamps and the current situation, and compares with the performance, evaluation and design of traditional lamps and lanterns. At the same time, it introduces the publication of the relevant standards of the International Electrotechnical Commission (IEC), the American Energy Star (EnergyStar), the North American Lighting Association (IESNA) in the LED lamps and the national standards of the LED lamps in China.

LED's entry into the field of lighting has triggered a new revolution in the field of lighting technology. Due to different shapes, numbers, sizes of LEDs can be arranged and combined in different ways, different LED replacement lamps can have different LED structures, etc., various types of LED lighting products (such as LED decorative lamps, LED road lamps, LED floodlights, embedded LED lamps, LED tunnel lamps, LED table lamps and traffic signal lamps, etc.) and traditional light source replacements (for example: LED instead of incandescent lamps, MR16, PAR lamps, straight fluorescent lamps) T8 / T12 etc.). With the continuous improvement of LED technology and the further improvement of people's pursuit of lighting sensory vision, people have more specific requirements on the design and performance of LED lamps, which puts forward higher requirements for lamp manufacturers and lighting product designers. For information about LED lights and other products, please click here: http: //

Semiconductor LED solid-state lighting is a newly developed industry in recent years. For lighting terminal product designers and lamp manufacturers, it is necessary to master the knowledge of the traditional lighting industry, domestic and foreign standards, and familiarize and understand the knowledge of LED devices. , In particular, it is necessary to accurately grasp the definition of LED lights and lamps and the difference with traditional lighting lamps. Because the semiconductor industry and the lighting appliance industry belong to different industries, and currently there is insufficient standard support for semiconductor LED solid-state lighting (SSL), at present, domestic LED lighting products are mixed, and the performance of the products claimed by manufacturers often differs from the actual results. Very far, the color quality and life expectancy are extremely exaggerated, which is unfavorable to the development of China's LED lighting industry and the cultivation of consumer confidence.

This article analyzes the characteristics and current problems of LED lamps and lanterns based on the definition of LED lamps and lamps and the current situation, and compares with the performance, evaluation and design of traditional lamps and lanterns. At the same time, it introduces the situation of LED lamps in China and internationally. It points out that the technical elements of LED lamps should be combined to observe and track the changes and development of standards.

1. LED lights, lamps and related definitions

1. LED lights

-LED package: an assembly of one or more LED chips that includes wire bonds or other types of electrical connectors, which may have optical components, thermal, mechanical, and electrical interfaces. The device does not include power supply and standard lamp head. The device cannot be directly connected to the branch circuit.

-LED array or module (LED array or module): an assembly of LED packages (components) or chips on a printed circuit board or substrate, which may have optical components, additional thermal, mechanical, and those intended to be connected to the load side of the LED driver Electrical Interface. The device does not include power supply and standard lamp head. The device cannot be directly connected to the branch circuit.

-LED light engine (LED light Engine): contains LED packages (components) or LED arrays (modules), LED drivers, and other photometric, thermal, mechanical, and electrical components. The device is directly connected to the branch circuit through a conventional connector that matches the LED lamp, which is designed not to use a standard lamp holder.

-Non-integrated LED lamp (LED lamp, non-integrated): an assembly containing an LED array (module) or LED package (component) and a standard lamp base. The device is intended to be connected to the LED driver of the luminaire via a standard lamp base. The device cannot be directly connected to the branch circuit.

-Integrated LED lamp (LED lamp, integrated): contains LED packages (components) or LED arrays (modules), LED drivers, standard lamp caps, and other photometric, thermal, mechanical, and electrical components. The device is intended to be directly connected to the branch circuit through a standardized lamp holder.

2. LED lamps

-LED luminaires are LED-based light-emitting components and matching drivers, as well as light distribution components, components for fixing and protecting light-emitting components, and complete lighting appliances that connect the appliance to branch circuit components. The possible forms of LED-based light emitting elements are LED packages (elements), LED arrays (modules), LED light engines or LED lamps. The LED luminaire is intended to be directly connected to the branch circuit.

-Hybrid LED luminaire: a luminaire equipped with LED-based light-emitting elements and other types of light sources such as incandescent or fluorescent lamps.

3. LED driver

LED driver (LED driver): a device containing a power supply and LED control circuit, the purpose is to make the LED package (component), or LED array (module) or LED lamp work.

Interpretation of the above definitions related to LEDs provides a basis for us to distinguish between LED lamps and LED lamps. In general, the main difference between LED light sources and LED lamps is whether they are directly connected to branch circuits. LED lamps are designed to not be connected to branch circuits. Directly connected products, and LED lamps are products designed to be directly connected to branch circuits.

The LED light engine is also an LED lamp, but its characteristics are between LED lamps and integral LED lamps. The difference from the integral LED lamp is that it contains a connector that matches the lamp, not the standard lamp head, but the difference from the LED lamp is It cannot be directly connected to the branch circuit. Due to the set light distribution function and standardized connectors, the LED light engine can improve the maintainability of some LED lamps.

Second, the difference between LED lamps and traditional light source lamps

At present, there are many differences between LED lamps and traditional light source lamps in terms of performance, evaluation and design.

1. In terms of performance evaluation of LED lamps

a) Evaluation of the uniformity of color space to evaluate the difference in color of different observation angles of the existence of LED lamps.

Traditional light sources have different characteristics of single illuminants. LED lamps used in LED luminaires are composed of multiple illuminants and emit light. There are color differences between the illuminants in LED luminaires. The color space uniformity evaluation needs to be used to evaluate the color of LED luminaires. Spatial distribution.

b) Use the life to evaluate the durability of LED lamps.

The measurement and evaluation of the life performance of traditional light sources have been standardized and are interchangeable, so the life of traditional light sources can be met by replacing damaged light sources and lamp control devices designed for 10 years of life, so they are generally not evaluated The life of traditional light source lamps. The life of LED lamps is related to many factors such as the life of the LED itself, the LED driver and the environment provided by the lamp to the LED, and there are many forms of LED lamps. Except for LEDs with standard lamp heads, other LED lamps are not interchangeable. The life span of different LED lamps can only be determined by the relevant life evaluation. When evaluating the life of LED lamps, it is necessary to claim not only the luminous flux maintenance life (LX), but also the failure rate (FX).

c) The evaluation parameters of the luminous flux ratio that can be used by lamps are different from traditional lamps. Traditional lighting fixtures are evaluated by the efficiency of the fixture, while LED fixtures use the evaluation of light efficiency.

d) Unlike traditional lighting sources, which can be used for photometric testing alone, the relative method can be used for photometric measurement. The LED light source is extremely sensitive to temperature. It is not suitable to separate the LED light source from the lamp for separate measurement. The absolute method should be used for photometric measurement. Perform photometric testing as a whole.

2. In the design of LED lamps

LED lamps are the same as traditional light source lamps in terms of optical system design, electrical accessories, heat dissipation measures and structure design.

There is a clear difference in comparison.

a) Optical system

The optical system of the lamp is the soul of the lamp. Its purpose is to design a lamp optical system that meets the specific lighting requirements according to the characteristics of the selected light source. Generally, the optical system of a traditional light source lamp is composed of a light source, a lamp holder, a reflector, and a light-transmitting cover. Because some LED units have a photometric characteristic of 2Ï€ light emission, the photometric system of the lamp is very different from the traditional light source lamp. The specific performance characteristics are as follows:

(1) The LED luminaire optical system is generally composed of LED chips and lenses composed of LED units or LED unit arrays. The array is sometimes arranged on a flat aluminum substrate, or may be on a protruding or concave molded substrate. The luminaire is used or not Use a light shield. The lamp manufacturer can combine multiple LED units or dozens of LED units on the substrate according to the lighting requirements. Care should be taken to control the consistency of the light color of the combined LED unit and assess the color space uniformity of the LED lamp.

(2) Because the photoelectric characteristics of LEDs are very sensitive to changes in the PN junction temperature; the encapsulation resin will rapidly deteriorate under high temperature and strong light irradiation; long-term light radiation will gradually reduce the photo-induced conversion rate of the phosphor and cause color seats The logo will be offset. When evaluating the life of LED luminaires, the lumen maintenance rate of LED luminaires is usually evaluated under the condition of limiting color shift.

b) Electrical accessories

LED drive power is the key factor that constitutes the performance of LED lamps, and is also one of the selection or design requirements of lamps. The electrical design of LED lamps should consider the characteristics and number of LEDs used, the installation location of the lamps, and the position of the lamps in the power grid to consider electrical safety, constant current drive, immunity, and EMI, and select or design an appropriate LED drive power supply.

Since the LED is driven by a low voltage constant current source of 2V ~ 3V, unlike ordinary incandescent bulbs, which can be directly connected to 220V AC mains, it is necessary to design a power supply and control circuit to drive the LED. In addition, the electrical connection of the LED module is also An important part of the electrical system of LED lamps, full consideration should be given to safety, and standard connectors, adequate insulation, and protection against electric shock should be used.

c) Heat dissipation measures

Like traditional light source lamps, LED lamps also generate heat. The heat of LED lamps comes from the loss in LED photoelectric conversion and LED drive power. Unlike the luminous principle of traditional electric light sources (the thermal radiation of incandescent lamps and the gas discharge of fluorescent lamps, etc.), the luminescence of LEDs is electroluminescence. Due to the problem of conversion efficiency, most of the energy output is mainly a lattice of non-radiative recombination The form of vibration transforms heat energy. And the way heat is transferred in the LED is not radiation but conduction. Therefore, the main goal in the heat dissipation design of LED lamps is to effectively conduct the heat of the LED chips and effectively control the LED junction temperature in the LED lamps.

For LED lamps, in addition to LEDs being heat-generating components, the drivers in LED lamps are also heat-generating components. In order to ensure a coordinated life with the LED light source, the thermal control of the LED driver is also very important. If the built-in driving power supply is used, the lamp should be based on its The internal ambient temperature selects the drive marked with the corresponding tc. When the driver is installed independently, the corresponding tc driver should be selected according to the possible ambient temperature of the installation location.

d) Mechanical components and structures

The role of machinery is to determine the position and relationship of the optical system, electrical system and thermal system of the lamp through structural design, so that the lamp can be fixed and used safely in the set environment.

The mechanical system of traditional lamps is composed of the structure of fixed light sources, reflectors, lamp control devices and other components, the routing structure of flexible cables or cords, sealing structure, mechanical protection structure, lamp fixing structure and lamp adjustment structure, etc. It is composed of lamp holder or light source connector, lamp holder mounting bracket, cord fixing frame, terminal block, housing, lampshade and lamp mounting frame. Due to the characteristics of LED light sources, LED lights have several forms such as packaging, modules, LED light engines, integral LED lights, and non-integral LED lights. Except for the last two forms, which may have similar internal structures as traditional light sources, other The LED lamp does not have a standard lamp base. In this case, the LED lamp has the following structural features:

-There is no lamp holder in the LED lamp, but the electrical connection between the LED lamp and the lamp is completed by the connecting piece, and the LED lamp is fixed to the lamp body by other methods.

-In order to export the heat generated by the LED chip, the LED lamp has a large number of heat sinks. The volume and weight of the lamp are much larger than the traditional light source lamp. The installation structure of the lamp should be considered accordingly to ensure the safety and reliability of the installation. At the same time, the heat sink should be designed to be easy to clean or not easy to deposit dust, otherwise, the efficiency of the heat sink will quickly decrease.

-When the LED luminaire uses a power cord, and the power cord can be disassembled for maintenance, it is a non-Z type connection. Just like the traditional light source with a non-Z type connection, the LED luminaire should also use a flexible cord fixing bracket.

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Heshan Jianhao Lighting Industrial Co., Ltd. , https://www.sunclubtw.com