the simulation with LED linear high bay

LED linear high bay is the trend of industrial lighting

Let’s talk about the trends and trends of industrial lighting. Everyone knows that ten years ago, most of our market products were large barrels of metal halide lamps, top square or round metal boxes, and better industrial lighting die-cast aluminum fin-type electrical boxes. works. The large 18-inch spinning aluminum reflector is hung below. The initial LED high bay light is the same as the metal halide lamp, just a light source. Next, I think it can be regarded as the age of the ufo mining lamp. This UFO LED high bay is also magical. It turned out to be a hit, and I couldn’t find the source.

the simulation with LED linear high bay

The simulation with LED linear high bay

However, this UFO LED high bay still does not get rid of the shadow of the traditional high bay light, the shortcomings of the application and the lack of light applications still make it slowly decline. UFO is still not good for many occasions, especially a large amount of storage lighting and high bay lighting in the low and medium spaces. At this time, the LED linear high bay fixture is slowly squeezed in with its slim slim body and flexible application, with professional optical applications. The linear lighting slowly took to the front of the Frankfurt exhibition and European lighting applications.

For large space areas such as open warehouses, lighting is required to be illuminance, uniformity and energy saving. In this kind of scene, 30 degrees, 60 degrees, 90 degrees, 120 degrees, etc. are selected according to the height, and the circular symmetrical light distribution is targeted. Linear lighting fixtures will be the best solution.

If you encounter this kind of shelf-type warehouse space, the lighting design should be different.

Elliptical strip light distribution lamps will be the best choice. Relatively circular light distribution lamps use elliptical light distribution in this scenario, the lamp power demand is reduced by at least 30%, and the warehouse usually has a very bright lighting time every day. Long, the electricity bill saved every day will be a large amount. You can save the cost of the lamp in less than two years, so it is especially advantageous for the energy-saving renovation project and the ppp project. After all, the savings are earned. of.

full spectrum led grow light

LED grow light manufacturer must know the knowledge

Various plants survive in a unique geographical environment, including sunlight, temperature, altitude and soil. They have formed a unique flowering and breeding response strategy in the evolution of the natural environment of hundreds of millions of years, which is to limit the flowering season to a suitable The period to ensure that the offspring can grow and develop smoothly, this is the photoperiod of plants. Most plants gradually adapt to the rhythm of the natural light environment during the natural selection and evolution process, forming a distinct seasonality of optimal reproduction. Studies have shown that photoperiod is an important environmental factor for inducing plant flowering, summarizing and analyzing the regularity of plant breeding performance, in order to improve the output efficiency of facility agriculture and promote the healthy development of agricultural planting industry.

The photoperiod is an important inducer of plant flowering. This paper summarizes the specific application of photoperiod in flowering of plants through the analysis of plant photoperiod physiological pathways, and points out that other environmental factors should be considered in the application, which provides useful ideas for the efficient development of plant agriculture flower planting industry. It also provides a scientific basis for LED manufacturers to produce plant growth lamps and control design.


full spectrum led grow light

Full spectrum LED grow light


Plant flowering photoperiod physiological pathway


Plant leaves sense photoperiod signals that conduct this flowering stimuli to the growth point of the stem tip. Photosensitive pigments and cryptochromes participate in this pathway as photoreceptors, and the flowering organs are controlled by gene expression to complete flowering control. Higher plants have at least three types of photoreceptors: sensitizing pigments that sense red and far-red light, and cryptochromes and photosensitizers that absorb ultraviolet (UV-A) and blue light.



Plant photoperiod response type


The transition from simple vegetative growth to nutrient and reproductive growth is a major turning point in plant life, and its importance is the continuation of the plant species itself. In 1920, W. W. Garner and H. A. Allard proposed the concept that the plant itself can measure the length of sunshine and can sense the season according to it, which is now called the photoperiod phenomenon.


In a certain developmental period, plants can be divided into long-day plants (abbreviated as LDP), short-day plants (short-day plants, abbreviated as SDP), and Japanese-negative plants according to the type of response to the length of sunshine. Day-neutralplant, abbreviated as DNP). LDP is a plant that must be lighted longer than a certain number of hours per day and can bloom after a certain number of days. Such as winter wheat, barley, rapeseed, fairy, sweet-scented osmanthus and sugar beet, etc., and the longer the illumination time, the earlier the flowering. SDP is a plant that must bloom for less than a certain number of hours per day. If the light is properly shortened, it can be flowered in advance, but if the light is extended, it will delay flowering or flowering. Such as rice, cotton, soybeans, tobacco, begonia, chrysanthemum, morning glory and cocklebur. DNP refers to plants that can bloom under any sunshine conditions, such as tomatoes, cucumbers, rose and Clivia.


Key issues in the application of plant flowering photoperiod regulation


1.plant critical day length

The critical day length of a plant refers to the longest sunshine that can be tolerated by short-day plant flowering during the day and night cycle or the shortest sunshine necessary to induce flowering of long-day plants. For LDP, the daily length is greater than the critical day length, and even 24 hours can be flowered. However, for SDP, the length of day must be less than the critical length to bloom, but too short to bloom. The Institute of Semiconductors of the Chinese Academy of Sciences and Baoding Dazheng Company should fully consider the chrysanthemum as the SDP factor in the edible chrysanthemum supplement project of Beijing Huitian Agricultural Cooperative.


2.Plant flowering key and artificial control of photoperiod

SDP flowering is determined by the length of the dark period and does not depend on the length of time of illumination. The length of sunshine required for LDP flowering is not necessarily longer than the length of daylight required for SDP flowering.


Knowing the key types of plant flowering and photoperiod response, you can extend or shorten the length of sunshine in the greenhouse, control the flowering period, and solve the problem of no flowering. Artificial extension of light can accelerate the flowering of long-day plants, and appropriately shorten the light, which can promote the flowering of short-day plants early. If you want to delay flowering or not flowering, you can reverse the operation. If the long-day plant is cultivated in the tropics, it will not bloom due to insufficient light. Similarly, the cultivation of short-day plants in the temperate zone and the cold zone will not bloom due to the long time of illumination.


3.introduction, breeding work


The artificial control of plant photoperiod is of great significance for the introduction and breeding of plants. For SDP, the northern seeds are introduced into the south, and they must be flowered in advance, requiring late-maturing varieties. Similarly, the southern species move northward and require early maturing varieties; for LDP, the northern seeds are introduced into the south, and it is necessary to delay flowering and require early maturing varieties. Similarly, the southern species move northward and require late-maturing varieties. For example, the genus Roselle is a SDP, and if the southern species moves northward, the vegetative growth period is prolonged. The bud, flowering, and seeding period are lagging, and it is very vulnerable to early frost damage. At this time, it should be known that shading treatment is required.


4.flowering induction of red light and far red light


Photofrin mainly receives red (Pr) and far red (Pfr) signals, affecting plant flowering induction. The flowering effect is not determined by the absolute amount of Pr and Pfr, but by the Pfr/Pr ratio. SDP is flowered at a lower Pfr/Pr ratio, while the formation of LDP flower stimulating substances requires a relatively high Pfr/Pr ratio. If the dark period is interrupted by red light, the ratio of Pfr/Pr is increased, which suppresses SDP flowering. The requirement of LDP for Pfr/Pr ratio is not as strict as SDP, but long enough illumination time, relatively high irradiance and far red light illumination are essential for inducing LDP flowering.


Problem discussion

1.vernalization and temperature environmental factors

The process of inducing plant flowering at low temperature is called vernalization. Vernalization plays an important role in flower induction as well as photoperiod. After germination of seeds or low temperature treatment of plants, the content of gibberellin in the body increases, which is a comprehensive consideration when using photoperiod to treat flowers.


In the photoperiod phenomenon, in addition to the dominant factor, other environmental factors such as temperature also affect the flowering induction of plants. Lowering the night temperature allows the LDP to induce flowering under shorter sunlight, while allowing the SDP to bloom under longer sunlight. For example, beets usually bloom under long days of sunshine, but at a low night temperature of 10 to 18 ° C, 8 hours of sunshine can also form flowers. The morning glory is short-lived at 21 to 23 ° C, but at 13 ° C low temperature. It is characterized by long-term nature.


2.photoperiod induction


When a certain physiological age is reached, the plant is treated with a suitable photoperiod of sufficient number of days, and even after an unfavorable photoperiod, the stimulating effect can be maintained and flowered.

The relationship between geographical environment and photoperiod


Most of the short-day plants are tropical and subtropical with short sunshine hours, and most of the long-day plants are native to temperate and cold zones. China is located in the northern hemisphere, and most of the areas belong to the mid-latitudes. In the mid-latitude region, spring has long-day conditions and autumn has short-day conditions, so both LDP and SDP are distributed, and the length of sunshine varies seasonally in different latitudes.


LED grow lights and control systems


The photoperiod control is a dark state of light illumination within a day, and can be manually and automatically changed. The LED control technology has been controlled by the initial single constant current, and has been developed to the current thyristor dimming, PWM dimming, DMX512, DALI, ZigBee and other protocol dimming. The control mode has also evolved from the earliest line control technology to IR, FR, Wi-Fi short-range wireless control. The controller adopts an embedded structure, which can monitor the optical parameters in real time, communicate data with the remote server through the Internet, and the system can easily realize the shading time control.



Photoperiod control has the characteristics of environmental safety, low cost of LED grow lights and labor saving, and is easy to operate under agricultural facilities. Therefore, rational and effective use of the photoperiod can break the seasonal restrictions of factory-cultivated plants within a certain limit, and achieve anti-seasonal stimulation or inhibition, in order to achieve the purpose of efficient production of agricultural products. With the continuous development of science and technology, the understanding of the phenomenon of photoperiod will inevitably become more profound. The application of photoperiod-regulating plant flowering and breeding to the factory-based breeding industry will promote the steady and rapid development of facility agriculture and LED grow lighting application industry.

Passive cooling and active cooling of led lighting fixture

How to design the heat dissipation of 347v-480v LED high bay

The effect of heat on the LEDs

LEDs are sensitive to temperature and performance is greatly affected by ambient temperature. Mainly in the following three aspects:

1. Excessive junction temperature can cause LED performance degradation, especially life, light color and lumen output. If the rated maximum junction temperature is exceeded, the LED’s lifetime will drop by 30% to 50% for every 10 degrees increase in operating temperature.

2. When the junction temperature rises, it will also cause obvious color drift to the high end of the spectrum (wavelength becomes longer), which has a great influence on the “white light” LED light source. Most of the so-called “white light” LEDs actually emit blue light, which turns into white light after being converted by phosphors. When the temperature rises, the blue light drifts toward the red spectrum, and the effect of the phosphor changes, and as a result, the color tone of the final light changes.

3. The last major parameter affected by the LED thermal management system is the lumen output. Increasing the current increases the lumen output of the LED, but a large current also causes an increase in heat generation. Therefore, an optimal balance must be chosen between system performance and service life when determining the current value.

In summary, excessive heat directly affects the short- and long-term performance of LED sources:

• Short-term: color drift, reduced light output

• Long-term: accelerated light decay and reduced life

Therefore, in order to obtain long-life, high-performance LED lamps, it is necessary to design an excellent cooling and cooling system. Thermal management can be said to be the most important part in the design of LED lamps. Natural (passive) and manual (active) cooling systems are often used to dissipate heat.


Passive cooling and active cooling of led lighting fixture

Passive cooling (a. LED luminaires using heat sinks) and active cooling (b, LED luminaires using heat sinks and fans).


1 passive cooling:

“Passive” means that the system does not contain energy-consuming mechanical equipment such as heat pumps, fans or fans. The most common passive heat sink in LED luminaires is the heat sink. In general, the heat sink consists of a number of sets of metal segments that quickly conduct heat from the LED source. Since the heat sink itself does not consume energy, it is the most energy efficient cooling system. However, as the power of the LED light source increases, the heat dissipation area is required to be larger and larger, which requires the design of a heat sink having a complicated shape, which adversely affects the design of the lamp.


2 active cooling:

“Active” means that the cooling system contains energy-consuming mechanical equipment such as pumps, fans or fans. For small luminaires that use high-power, high-light-packaged LED light sources, an active cooling system is necessary because it allows for a smaller luminaire structure and size.


How to design a passive cooling system?

The most common type of LED luminaire is the passive cooling system. Several factors must be considered when designing such a system, such as the layout of the LED source, the properties of the luminaire material, the shape and surface treatment of the heat sink, and other factors described below.


1.347v-480v LED high bay layout spacing

Most of the energy consumed by the LED is converted into heat, and the tighter the LED particle layout, the less heat dissipation, and the higher the junction temperature. Therefore, the LED particles should be as large as possible under the conditions allowed by the package and optical characteristics.

led layout spacing

LEDs layout spacing


2.Material properties

Thermal conductivity is a physical quantity used to measure the efficiency of heat transfer. The thermal conductivity of a material reflects the thermal conductivity of the material. Some materials are good conductors of heat compared to other materials. For example, the thermal conductivity of pure copper is 400W/m.K, and the thermal conductivity of air is only 0.025W/m.K.

Aluminum is a common material for making heat sinks, not only because of its high cost performance, but also because of aluminum, easy processing, die casting, and extrusion. Another feature of the heat sink is the geometric shape, while the aluminum profile is easy to shape. In addition, aluminum has advantages such as light weight, corrosion resistance and good structural stability. In summary, aluminum is an excellent material for making heat sinks.


Material Thermal conductivity(W/m·k)
Stainless steel 12.11~45
Aluminium 237
Copper 401



Convection is a fluid process that removes heat from the surface of a object by the flow of a gas or liquid. The larger the surface area, the more convection occurs. An example is the heat sink, which is designed to be the current shape to maximize the surface area of ​​the convection. This multi-bladed structure can greatly increase the surface area without changing the volume.

4.Surface treatment

The emissivity is a physical quantity that reflects the relative ability of the surface to radiate energy from the surface of the object, usually written as ε or e. It is defined as the ratio of the radiant energy of a material’s surface to the standard and the energy radiated by the black body at the same temperature. The ideal black body has ε=1, while the real material ε<1. High emissivity coatings increase the rate of heat exchange. Generally, the darker and darker the surface, the closer the emissivity is to one. The higher the reflectivity of the material, the closer the emissivity is to zero. Printed circuit board (PCB) LEDs are mounted on multi-layer FR4 or metal printed circuit boards (MCPCB). For best performance, the thermal resistance of the PCB should be as low as possible.

5.FR4 board (FR4 PCB)

FR4 is the standard material for making PCBs. The number of LED particles installed on each PCB depends on the LED input power and boundary conditions. The heat on the PCB is transferred to the heat dissipation system through the heat dissipation holes. These heat dissipation holes are plated through holes (PTH), which can be opened, blocked or closed. Finally, the thermal resistance of the entire board is determined by the number and density of the heat sink holes on the board, the thickness of the copper foil layer, and the plating thickness of the plated through holes.

6.Metal circuit board (MCPCB)

The following figure shows the structure of the MCPCB. An MCPCB board consists of a copper layer, an insulating layer and a heat sink, aluminum or copper. Increasing the thickness of the copper layer or thinning the thickness of the insulating layer can greatly reduce the thermal resistance.


7. Surface roughness

When the heat sink is connected to the packaged semiconductor, the two parts of the solid surface are required to be as close as possible. Unfortunately, no matter how well handled, the solid surface cannot be completely smooth. Due to the unevenness of the microstructure, all surfaces have a certain roughness. The presence of these small protrusions, small dimples or twisted shapes superimposes to form a rough, uneven surface visible to the naked eye. When two such surfaces are in contact, only the small protrusions on the two faces are actually in contact with each other, and the small cavities are still separated to form an air gap.

Thermal Interface Materials (TIMs), also known as thermal conductive materials, are used to increase the heat transfer coefficient between bonded solid surfaces, such as PCB boards and heat sinks, to improve heat dissipation efficiency. Because if not filled, the air-filled gap between the surfaces of the two mechanically joined materials can be a poor conductor of heat.


8.Thermal interface material

a) unfilled voids; b) TIMs material filling

The most common thermal interface materials are white or thermal paste. The most common is thermal grease, which is doped with alumina, zinc oxide or boron nitride. Some brands of thermal interface materials use finely ground silver powder. Another large class of thermal interface materials are phase change materials. These materials are solid at room temperature and liquefy at the working temperature of the chip.


9.Production Process

The most common technique for utilizing natural convection is to make several holes in the top and bottom of the package, allowing the airflow to pass up and down to dissipate heat from the LED. Compared to the two processes of die casting and extrusion, the aluminum profile treated by the extrusion process will be denser (making fewer bubbles inside the heat sink). Since the difference in thermal conductivity between air and aluminum is so large, a little bit of air residue can cause a significant change in the thermal conductivity of the material. The thermal conductivity of die-cast aluminum heat sinks is on average 20-30% lower than extruded aluminum heat sinks of the same volume and shape.


10.Shell design and installation method

When designing the LED housing, consider also leaving a thermal path from the PCB backplane to the enclosure. It is common practice to mount the back side of the PCB directly onto the LED housing to maximize contact between the two.

The improvement of this installation method is to add a heat conducting plate between the PCB board and the outer casing, and the heat conducting board can be better fitted with the PCB board to increase the contact area of ​​heat conduction.

Similarly, the most common technique for utilizing natural convection is to make several holes in the top and bottom of the package, allowing the airflow to pass up and down to dissipate heat from the LEDs.

smart control led lighting

In addition to the US trade war, you may not pay attention to the EU GDPR

In fact, the frequent US trade wars around the world have also prompted countries around the world to make relevant counter-measures or protective measures to maintain economic security in their own countries or regions, which has made global mesh trade more and more Complex and changeable.

We believe that at this stage, it is more worthy of attention for China’s LED lighting companies to impose tariffs with the United States. The EU’s General Data Protection Regulation (GDPR) has already entered into force on May 25, but it has not Caused enough attention.


GDPR is known as the most stringent data protection bill in the history of the European Union. Why do you say that? GDPR covers the definition of personal assets very broadly. “In addition to personal phone numbers, addresses, health information, e-mail, etc., such as fingerprints, face recognition, retinal scans, online identification codes, and online location data. Such as cookies, IP locations, mobile device IDs, etc., all included in the scope of capital.”

The “three most”, which has the widest scope of application, the strictest regulations and the most expensive punishments, has attracted the attention of all parties. Moreover, in terms of the scope of influence, GDPR is not only applicable to enterprises that set up subsidiaries or branches in the EU, but also applies to all foreign companies in the EU that have handled the capital of EU residents. This means that regardless of the size of the company, across the service, technology, manufacturing, and financial industries, it will inevitably be affected. As long as companies have computer systems, servers and employees using mobile phones, they may touch the GDPR specification, and the unpredictable uncertainty will eventually become a risk.

Do you know that if you infringe on GDPR, how many penalties are there? Let me give you an example. Austrian activist MaxSchrems quickly filed suit against Google’s Android system, Facebook and its affiliates of Instagram (IG) and WhatsApp for a number of violations.

According to the GDPR regulations, companies that violate this law will face a fine of up to 20 million euros or 4% of global annual turnover (both high). According to this rule, if the European regulators are illegal, the parent company of Google will face a maximum fine of 3.7 billion euros. Facebook and its two subsidiaries, WhatsApp and Instagram, each face a maximum fine of 1.3 billion euros, and the amount is close to antitrust. The punishment of the law.

Now it is time to understand why GDPR is called the most stringent data protection program in the history of the EU? !

When the smart bulb returns to a normal light bulb in one second

Then you may ask, what does this have to do with our LED lighting companies? Yes, this is the place to be especially careful – LED smart lighting products. As long as personal assets (IP, face, cookies, etc.) are protected by GDPR, can LED smart lighting companies, especially smart home lighting, smart commercial lighting and other Internet of Things companies be careless? !

smart control led lighting

Although as early as 2014, Chinese company Xiaomi set up a privacy committee, and the official certification body launched privacy protection related business. By 2016, the MIUI operating system and the domestic and international versions of received the TRUSTe privacy certification. However, Xiaomi The Xiaoe Smart Light of its eco-chain company was forced to close its service because it could not comply with the GDPR regulations in time. When the smart bulb degenerates into a normal light bulb for one second, some people suspect that the light will record the user’s switch light record.

Yeelight CEO Jiang Zhaoning once said that the closure of the data service is based on the GDPR test for non-EU companies, but only temporarily offline.

In addition to Yee Light, there are also a handful of export companies that are known to have smart lighting concepts in China. Although accurate data is not yet available, for example, LED-based smart bulbs, smart home lighting, smart street lights, and intelligent control systems are the leading export-oriented enterprises (the list of enterprises is no longer listed, there are a lot of them). Special attention should be paid to the impact of GDPR. Even Chinese lighting companies that work for foreign companies cannot be ignored.

What is more noteworthy is that some experts believe that the next stop of the data “strict law” will not only be in the EU, but also may be of reference and reference for other countries and regions, such as North America, Asia and the Gulf Arab region. If so, the scope and measures for the protection of personal data in the future will greatly affect the global business landscape, and the impact will be far-reaching.

For the lighting industry, when a smart light bulb becomes an ordinary light bulb and a smart light fixture returns to a normal light fixture, where will China’s smart LED lighting companies go? We wait and see.


Trump plus tariffs to 200 billion US dollars

What is the impact of the LED industry on Trump plus tariffs to 200 billion US dollars?

On July 10th, the Trump administration promoted the plan to impose tariffs on China’s $200 billion in goods and released a list of target products. The LED industry may be affected.

The first round of taxation projects for industrial intermediates has limited impact. In 2017, China’s exports to the United States were about 175 million US dollars. Therefore, the impact on China’s LED industry is quite limited. The main impact is that CREE has lighting factories in the United States. American manufacturer of LEDs from China.

Trump plus tariffs to 200 billion US dollars

Trump plus tariffs to 200 billion US dollars

The second round of 200 billion LED products covered a wide range of products, including LED and lighting categories of more than 10 items, and the trade volume is also large, of which the main lighting products in 2017 China exports to the United States The amount is as high as more than 5 billion US dollars.

Because the United States has always been an important export market for China’s LED downstream including lighting and other industries, if the 200 billion US dollar tariff project is approved, China’s LED-related industries will inevitably suffer.

However, due to the obvious advantages of China’s lighting industry, it has formed a global industrial cluster. Compared with other regions in the world, it has obvious comprehensive cost advantages. Therefore, more than 85% of global LED lighting products are assembled and produced in China.

Even with a tariff of more than 10%, it is difficult for US consumers to obtain alternative products from other regions in the short term, and 10% of the additional tariff costs will be shared between US consumers and Chinese lighting manufacturers.