Presently, the heat dissipation of LED strips is one of the major issues for LED light strips companies. The aluminum substrate is used to overcome the difficulty, for it has the great thermal conductivity and excellent heat dissipation. The substrate is a unique copper clad laminate with good thermal conductivity, electrical insulation properties, and machinability. The PCB should be mounted close to the metal base as far as possible to lessen the thermal resistance.
Initially, the features of the aluminum PCB.
1. Using surface mount technology (SMT).
2. The particular circuit design is beneficial for heat diffusion.
3. The lower working temperature of LED lights, improve the dependability, as well as increase service life.
4. Decreasing sizes of the product, and costs of hardware and assembly.
5. Having better mechanical durability than other traditional substrates.
The aluminum-based PCB consists of the copper foil, the thermally conductive insulation layer and the metal plate, and its composition is classified into 3 layers:
1. Circuit layer: it is the same as normal copper clad, and its thickness is 1oz to 10oz.
2. Dielectric layer: also known as the insulation layer, is a low thermal resistance material covering on the LED light strip.
3. Base layer: it is a metal board, usually aluminum or copper.
The circuit layer is the printed circuit that used to connected different components. In most cases, the circuit layer needs to have a large current carrying ability, so that the thick copper foil should be utilized.
The heat conductive insulation layer is the key of the aluminum PCB, which has small heat resistance, great viscoelasticity, resistance to heat aging, and can resist physical and thermal stress.
The metal plate is the base of the substrate, which is needed to has great thermal conductivity. In production, aluminum plate and Copper plates are most commonly applied, which suited to traditional machinings including drilling, punching, and cutting etc.
Aluminum PCB materials have advantages that are unmatched by other materials, such as no need for a heat sink, greatly reduced sizes of LED lights, excellent heat dissipation, good insulation, and mechanical properties etc.
2018年10月4日星期四
2018年9月27日星期四
The effect of LED grow light on plant senescence
Chlorophyll degradation, rapid protein loss, and RNA hydrolysis during plant senescence are mainly characterized by leaf senescence. Chloroplasts are hypersensitive to the change of surrounding light. The red light, blue light, and red-blue mixed light are conducive to the formation of chloroplasts. Blue light is helpful to increase the starch granules in chloroplasts. Red light and far-red light inhibit the development of chloroplasts. The red-blue light can boost the synthesis of chlorophyll in cucumber seedling leaves and also delay the attenuation of chlorophyll content in the later stage. This effect is more obvious with the decrease of red light ratio and the increase of blue light ratio. The chlorophyll content of cucumber seedlings under LED red-blue combined light treatment was significantly higher than monochromatic red and blue light treatment. LED blue light could significantly increase the chlorophyll a/b value of black-spotted and green garlic seedlings.
During the leaf senescence, the content and activities of cytokinin (CTK), auxin (IAA), abscisic acid (ABA) are changed. Different light qualities have different effects on phytohormones. CTK stimulates leaf cell growth, promotes photosynthesis, inhibits the activity of ribonuclease, deoxyribonuclease and protease, and slowdowns the degradation of nucleic acids, proteins and chlorophyll, hence slowing leaf senescence. IAA is principally centered in the region where growth is strong. Violet light can increase the activity of indoleacetic oxidase, and low IAA levels prevent elongation. ABA is generally produced in senescent leaf tissues, mature fruits, seeds, stems, and roots. Compare with the white light and blue light, the red-blue LED grow light will decrease the ABA content of cucumber and cabbage to a greater extent.
Peroxidase (POD), superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT) are important and photoconductive protective enzymes. In the process of plant aging, the activity of these enzymes will decrease rapidly. The effects of different light qualities on the antioxidant enzyme activities of plants were significant. Illumination rapeseed seedlings for 9 days with red light, APX activity increased significantly and POD activity decreased. After 15 days of red and blue light irradiation, the POD activity of tomato was higher than that of white light 20.9% and 11.7% respectively. After 20 days of green light treatment, the POD activity was the lowest, only 55.4% of white light. For cucumber seedling leaves, blue light can obviously boot the soluble protein content and increase the activities of POD, SOD, APX, and CAT. Furthermore, the activity of SOD and APX gradually decreased with the extension of illumination time. The activity of SOD and APX under blue light and red light decreased slowly but were always higher than white light. Red light irradiation significantly reduced the activity of IAA peroxidase in tomato leaves, such as peroxidase, IAA peroxidase, and eggplant leaves, but caused the peroxidase activity of eggplant leaves to increase significantly. Therefore, the use of reasonable LED grows light strategy can effectively delay the aging of plants.
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| COB LED red-blue combined plant grow light |
During the leaf senescence, the content and activities of cytokinin (CTK), auxin (IAA), abscisic acid (ABA) are changed. Different light qualities have different effects on phytohormones. CTK stimulates leaf cell growth, promotes photosynthesis, inhibits the activity of ribonuclease, deoxyribonuclease and protease, and slowdowns the degradation of nucleic acids, proteins and chlorophyll, hence slowing leaf senescence. IAA is principally centered in the region where growth is strong. Violet light can increase the activity of indoleacetic oxidase, and low IAA levels prevent elongation. ABA is generally produced in senescent leaf tissues, mature fruits, seeds, stems, and roots. Compare with the white light and blue light, the red-blue LED grow light will decrease the ABA content of cucumber and cabbage to a greater extent.
Peroxidase (POD), superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT) are important and photoconductive protective enzymes. In the process of plant aging, the activity of these enzymes will decrease rapidly. The effects of different light qualities on the antioxidant enzyme activities of plants were significant. Illumination rapeseed seedlings for 9 days with red light, APX activity increased significantly and POD activity decreased. After 15 days of red and blue light irradiation, the POD activity of tomato was higher than that of white light 20.9% and 11.7% respectively. After 20 days of green light treatment, the POD activity was the lowest, only 55.4% of white light. For cucumber seedling leaves, blue light can obviously boot the soluble protein content and increase the activities of POD, SOD, APX, and CAT. Furthermore, the activity of SOD and APX gradually decreased with the extension of illumination time. The activity of SOD and APX under blue light and red light decreased slowly but were always higher than white light. Red light irradiation significantly reduced the activity of IAA peroxidase in tomato leaves, such as peroxidase, IAA peroxidase, and eggplant leaves, but caused the peroxidase activity of eggplant leaves to increase significantly. Therefore, the use of reasonable LED grows light strategy can effectively delay the aging of plants.
2018年9月26日星期三
Blue light chip in the white light LED
In normal conditions, white light LEDs have a blue light source. An ordinary white-light LED is consisted of the blue-light LED chip and the fluorescent substance. It works very simply, that is the chip illuminates blue-light to the fluorescent powders to emit the white light.
In the 1960s and 1970s, red and green LEDs were successively created. However, the blue-light chip has still not been invented, for it has greater photon energy, and is difficult to grow blue-light materials. Due to the difficulties and cost, a lot of institutes quit. However, two Japanese researchers who keep working at it and eventually invented blue-light LEDs for the first time in 1989. At that time, the light was very weak and had no practical application value, but it gave people hope of developing blue-light LEDs. Finally in 1993, a staff of Nichia, Nakamura Shuji invented the high-brightness blue-light chips technology. Thanks to this technology, the white light LED lighting has really stepped out of the laboratory into practical production and application. Today we can conclude that, without the blue-light chip, white-light LEDs is extremely hard to popularize.
There is some date show the influences that the blue-light LED brought to our lives and environment. According to relevant information, the worldwide annual electricity consumption is about 200 billion kWh, of which about 19% is used for lighting. Imagine if all incandescent lights (electrical conversion rate of about 10%), fluorescent lights (electrical conversion rate of about 30%) are replaced with white LED energy-saving lights (electrical light conversion rate of 50% or more), then a minimum of 1.52 billion kWh of electrical energy is saved on a yearly basis. Furthermore, it reduces coal consumption by about 500 million tons, reduces carbon dioxide emissions by about 1.3 billion tons, and reduces sulfur dioxide emissions by about 4.2 million tons. These tangible data highlight the significance of the blue light LED.
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| Whit light SMD LED |
In the 1960s and 1970s, red and green LEDs were successively created. However, the blue-light chip has still not been invented, for it has greater photon energy, and is difficult to grow blue-light materials. Due to the difficulties and cost, a lot of institutes quit. However, two Japanese researchers who keep working at it and eventually invented blue-light LEDs for the first time in 1989. At that time, the light was very weak and had no practical application value, but it gave people hope of developing blue-light LEDs. Finally in 1993, a staff of Nichia, Nakamura Shuji invented the high-brightness blue-light chips technology. Thanks to this technology, the white light LED lighting has really stepped out of the laboratory into practical production and application. Today we can conclude that, without the blue-light chip, white-light LEDs is extremely hard to popularize.
There is some date show the influences that the blue-light LED brought to our lives and environment. According to relevant information, the worldwide annual electricity consumption is about 200 billion kWh, of which about 19% is used for lighting. Imagine if all incandescent lights (electrical conversion rate of about 10%), fluorescent lights (electrical conversion rate of about 30%) are replaced with white LED energy-saving lights (electrical light conversion rate of 50% or more), then a minimum of 1.52 billion kWh of electrical energy is saved on a yearly basis. Furthermore, it reduces coal consumption by about 500 million tons, reduces carbon dioxide emissions by about 1.3 billion tons, and reduces sulfur dioxide emissions by about 4.2 million tons. These tangible data highlight the significance of the blue light LED.
2018年9月25日星期二
Effects of LED Grow Light on Nutritional Quality of Fruits and Vegetables
The proteins, carbs, organic acids and vitamins in fruits and vegetables are good for human health. Light quality can influence the content of VC in crops through controlling the activity of VC synthesis and decomposing enzymes, in addition, to regulate the protein metabolism and carbs buildup in horticultural plants. Red light stimulates the accumulation of carbs, and blue light is helpful to protein structure, while the mixture of red and blue light has an appreciably greater influence on the nutritional quality of plants than single color light. For lettuce, LED red or blue light can decrease the nitrate, applying blue or green light can boost the amount of soluble sugar, and replenishing infrared light is effective to promote the VC synthesis. For tomato growing, blue light LED grow lights can enhance the content of VC and soluble protein. The mix of red and blue light and red light can increase the value sugar and acid. Furthermore, red and blue combined light can raise the VC content in
cucumber.
The phenolic substances, flavonoids, anthocyanins and other substances contained in fruits and vegetables do not merely have a significant effect on the color, flavor and commercial value of vegetables and fruits as well as have natural antioxidant activity, which can effectively inhibit or eliminate free radicals in human body. The use of LED grow lights with blue light can truly improve the anthocyanin of eggplant by 73.6%, while utilizing of LED red light, red and blue mixed light can increase flavonoids and total phenolic content. Blue light can increase the content of lycopene, flavonoids, and anthocyanins in tomato. The combination of red and blue light advances the creation of anthocyanins but prevents the synthesis of flavonoids. In contrast to the white light LED plant lights, red light can enormously boost the anthocyanin content in the upper part of lettuce, nevertheless, the blue light treated lettuce has the lowest anthocyanin content. The entire phenolic content of green leaf, purple leaf, and red leaf lettuce had greater amounts under white light, red and blue combined light, and blue light, but the smallest value under red light. Supplementing LED UV or orange light can raise the value of phenolic compounds in lettuce leaves while providing green light can increase anthocyanin content.
Consequently, the effective use of LED grow lights with suitable color is a useful method to enhance the nutritional quality of facilities fruits and vegetables.
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| LED plant grow light with red and blue combined light |
The phenolic substances, flavonoids, anthocyanins and other substances contained in fruits and vegetables do not merely have a significant effect on the color, flavor and commercial value of vegetables and fruits as well as have natural antioxidant activity, which can effectively inhibit or eliminate free radicals in human body. The use of LED grow lights with blue light can truly improve the anthocyanin of eggplant by 73.6%, while utilizing of LED red light, red and blue mixed light can increase flavonoids and total phenolic content. Blue light can increase the content of lycopene, flavonoids, and anthocyanins in tomato. The combination of red and blue light advances the creation of anthocyanins but prevents the synthesis of flavonoids. In contrast to the white light LED plant lights, red light can enormously boost the anthocyanin content in the upper part of lettuce, nevertheless, the blue light treated lettuce has the lowest anthocyanin content. The entire phenolic content of green leaf, purple leaf, and red leaf lettuce had greater amounts under white light, red and blue combined light, and blue light, but the smallest value under red light. Supplementing LED UV or orange light can raise the value of phenolic compounds in lettuce leaves while providing green light can increase anthocyanin content.
Consequently, the effective use of LED grow lights with suitable color is a useful method to enhance the nutritional quality of facilities fruits and vegetables.
2018年9月24日星期一
Matters needing attention for LED strips installation
In the marketplace and on the web, many people sometimes asking why the LED strips' brightness is lower, the lifetime is shorter in the abnormal range than the theoretical value provided by the supplier. There are various causes of this condition, apart from some dishonest businesses sell seconds at best quality prices, the incorrect use is the major factor. Therefore, it is necessary to pay our attention to numerous issues during install for the LED lights.
Firstly, the wiring way of LED light strips. The most of LED light bars are adopt input voltage of DC12V or DC24V, which must be powered by the matching power supply. The total power must be greater than the sum of the connected LED lights. The wiring of the LED tapes needs to be correctly welded by anode and cathode. Commonly, LED light strips producers will clearly mark the anode (+) and cathode (-) beside the bonding pad as well as solder the wires in one end or both ends. Furthermore, if you want to save money on the power supply, there is a cost-effective choice that you can parallel connect the LED strips, and just need a matched high power supply.The second thing is the connection of the controller. RGB LED lights need to connect with the controller to realize various lighting effects. The three chips in the RGB LED usually share one positive pole, so the RGB LED tapes to have one "+" bonding pad and three "-" bonding pads. Different controllers have different control distance. The farthest distance of ordinary controller is 10 to 15 meters, some better controllers are about 20 meters and the best's remote distance up to 30 meters.
Last but not least, the total length of the LED strips. In most cases, we suggest a parallel connection, for the overlong series connection length, will case the brightness reducing and excess temperature. LED lights' working lifetime will be dramatically reduced in the excessive temperature condition.
Consequently, at the time of installation, we must follow the relevant instructions and requirements.
2018年9月20日星期四
Influences of LED plant lights on the horticultural plants
The control of light on plant growth includes seed germination, stem elongation, leaf and root improvement, phototropism, chlorophyll synthesis and decomposition, and flower induction. The light environment features in the facility include illumination intensity, photoperiod, and spectral distribution. The man-made supplemental light can direct controls these light features without being affected by the weather.
Plants absorb specific light and use different photoreceptors to identified different light signals. At present, there are three types of photoreceptors are found in plants, including a Photosensitive element (absorbing red and far-red light), Cryptochrome (absorbing blue light and near-ultraviolet light), and ultraviolet light receptors (absorbing UV-A and UV-B). Illuminating the plants by LED plant grow lights with particular wavelength can boost the photosynthesis, increase the growth and improvement of the plant.
Photosynthesis mostly applies red-orange light (610-720nm) and blue-violet light (400-510nm). It can be realized by LED manufacturing technology that emitting single color light with a particular wave crest according to the wavelength band that the chlorophyll has the strongest absorption. Nowadays, based on relevant experiments, we knew that the red-orange light will benefit the plants' growth, dry matter's accumulation, organic formation, as well as promote precocious flowering and fruiting. The Blue-violet light can regulate the phototropism of leaf, boost stomatal opening, chloroplast activity and boost organs development, meanwhile inhibit stem elongation, control over growth and postpone flowering. The red and blue mixed LED grow lights have a lot of advantages that the single color light have not, it can release the specific spectrum that basically facilitates photosynthesis and morphogenesis. The energy efficiency is outstanding and the light energy utilization is able to get 80% to 90%.
In the facility gardening production, LED plant grow lights have a great promoter action. In the entire growing period of time, controlling light quality, intensity, and lighting period by LED plant lights, can lessen the growth cycle, enhance the yield, nutritive value and form value of agricultural products, as well as realize efficient, economical and intelligent manufacturing of facility horticultural plants.
Plants absorb specific light and use different photoreceptors to identified different light signals. At present, there are three types of photoreceptors are found in plants, including a Photosensitive element (absorbing red and far-red light), Cryptochrome (absorbing blue light and near-ultraviolet light), and ultraviolet light receptors (absorbing UV-A and UV-B). Illuminating the plants by LED plant grow lights with particular wavelength can boost the photosynthesis, increase the growth and improvement of the plant.
Photosynthesis mostly applies red-orange light (610-720nm) and blue-violet light (400-510nm). It can be realized by LED manufacturing technology that emitting single color light with a particular wave crest according to the wavelength band that the chlorophyll has the strongest absorption. Nowadays, based on relevant experiments, we knew that the red-orange light will benefit the plants' growth, dry matter's accumulation, organic formation, as well as promote precocious flowering and fruiting. The Blue-violet light can regulate the phototropism of leaf, boost stomatal opening, chloroplast activity and boost organs development, meanwhile inhibit stem elongation, control over growth and postpone flowering. The red and blue mixed LED grow lights have a lot of advantages that the single color light have not, it can release the specific spectrum that basically facilitates photosynthesis and morphogenesis. The energy efficiency is outstanding and the light energy utilization is able to get 80% to 90%.
In the facility gardening production, LED plant grow lights have a great promoter action. In the entire growing period of time, controlling light quality, intensity, and lighting period by LED plant lights, can lessen the growth cycle, enhance the yield, nutritive value and form value of agricultural products, as well as realize efficient, economical and intelligent manufacturing of facility horticultural plants.
2018年9月18日星期二
The difference between high power and low power LEDs
LEDs are the pointolite, different from compact fluorescent and incandescent lamps in the marketplace. The pointolite, as the name suggests, is a light source that glows evenly from a point to the surrounding space.
Generally, the specifications of most low-power LEDs are 0.1 watts, 0.2 watts, and 0.3 watts, of which a 0.3 watt LED's luminous flux reach up to 45lm. Therefore, we call the LED with a power of 0.5 watts or more as the high-power LED, of which a 0.5 watt LED can reach up to 60 lm and a 1 watt LED's maximal luminous flux is 110 lm. That is the difference in lumination between the two.
If you're looking for lighting products that apply to your house, then the low-power LEDs will be satisfactory, but in advertising lighting, outdoor lighting and other public lighting, high-power LEDs would be a better choice.
Economically, the price of high-power LEDs is commonly more expensive. High-power LEDs have higher energy consumption, higher lumination, and more heat production. In order to ensure the reliable quality and long working lifetime, LED lights manufacturers must use materials with high heat dissipation efficiency and superior quality, such as gold wires, copper-bases, highly conductive PCB and so on.
With the progress of relevant production technology, the LED with power exceeding 200 watts can be manufactured by the LED lights factory. However, the cost performance of these ultra high-power LEDs is too low to popularize. Presently, the LED strip lights with 0.5 watt LEDs is one of the top sellers LED strips, for its moderate price, high brightness, good heat dissipation, and wide applicability. The LED strips made of 0.5 watt LEDs can be applied to indoor lighting, outdoor lighting, advertisement lighting etc.
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