LED's small and lightweight, low driving voltage, full color, long life, high efficiency, resistance to vibration, easy to control light and other characteristics, provide superior conditions for the design of lighting systems for different locations and purposes. People are accustomed to seeing things under the sun. For general lighting, people need light sources that are close to the quality of sunlight, so white LEDs are an important indicator of semiconductor lighting technology. Since a single LED has low power and low brightness, it should not be used alone. For this reason, multiple LEDs must be assembled together to be a practical LED lighting system. However, there is still a certain distance between the requirements of white LEDs and general lighting, and there are many technical and cost issues that need urgent solution.
1, the main technical overview of semiconductor lighting system
1) The thermal management of a luminaire system is often referred to as a cold light source. This is because the principle of LED luminescence is that electrons emit photons directly after recombination without the need for a thermal process. However, due to the presence of Joule heat, LEDs emit heat while accompanied by heat, and for high-power and multiple LED applications, the heat quantity becomes less and less, LED is different from traditional lighting sources such as incandescent lamps and fluorescent lamps. Excessive temperatures can shorten or even terminate their service life. Moreover, the LED is a temperature-sensitive device. When the temperature rises, its efficiency drops sharply. Therefore, the system structure design and the development of the heat dissipation technology are also problems faced by the LED application. Since forced air cooling is often not desirable in light sources, heat sinks and other methods for enhancing natural convection cooling are playing an increasingly important role in the design of LED lamps and light sources as input power increases.
2) Enhancing color rendering Currently, white LEDs commonly use blue emitting LEDs to superimpose yellow-emitting YAG phosphors excited by blue light into white light. Since the luminescence spectrum contains only two spectra of blue and yellow, there is a problem that the color temperature is high and the color rendering index is low, which does not meet the general lighting requirements. The sensitivity of the human eye to chromatic aberration is much higher than the sensitivity to light intensity. For illumination, the color rendering of the light source is often more important than the luminous efficiency. Therefore, adding an appropriate amount of red emitting phosphor and maintaining high luminous efficiency is an important issue in LED white lighting.
3) The secondary optical design of the lamp system Traditional lamps have long used incandescent lamps and fluorescent lamp sources as the reference to determine the standard of the lamp's optics and shapes. Therefore, the LED lamp system should consider abandoning the assembly method of traditional lamps and LED lighting modules. Taking into account its optical characteristics, different lamps are specially designed for LED light sources. The optical system design content mainly includes the following aspects: 1 According to the requirements of the lighting object and luminous flux, the shape of the optical system, the number of LEDs, and the power are determined; 2 A plurality of LED light emitting tube combinations are designed as a point light source, a ring light source or The "secondary light source" of the surface light source calculates the illumination optical system according to the combined secondary light source. 3 It is very important to control the light distribution of each LED tube on the "secondary light source" that constitutes the illumination optical system.
Because the light beam emitted by the LED is concentrated, it is easier to control and does not require the reflector to collect light, which is beneficial to reduce the depth of the lamp. For example, using a planar mirror optics system, one or two LEDs can be used to illuminate a large surface, while the depth of the lamp is very thin; and using light guide technology, the LED is directly mounted beside the light guide, which can greatly reduce the light source and other components. Occupied by the volume, made of ultra-thin lamps.
4) Integration of power supplies, circuits, and luminaires. Designing luminaires for LEDs requires attention. One issue that incandescent and fluorescent luminaire designers rarely care about is the power supply. Most incandescent lamps are powered directly from the AC line, so no power is required. Fluorescent lamps use ballasts to complete the power function. However, LEDs need a dedicated power supply and driver circuit, and they should be considered when designing lamps.
The major characteristics of semiconductor lighting and solar power generation are environmental protection, energy saving, long life, and safety. The combination of solar power generation and semiconductor lighting to complete the conversion of photoelectric to electro-optic light is the best combination. Natural energy-utilizing independent semiconductor lighting fixtures that use solar battery power as a power source are energy-saving, environmentally-friendly, and long-lived. They also eliminate the related wires and supporting facilities and have a huge market space.
5) to improve the reliability of the system LED light source is called it longevity lamp, as a solid light emitting device, the theoretical life of more than 100,000 hours, its life is much longer than the traditional light source, so in some difficult to replace and maintain the occasion to use, Its maintenance costs can be greatly reduced. However, in many practical applications, this advantage cannot be seen. Instead, the user sees that the light fades badly and has a short life span. It takes only less than 10,000 hours to be broken. This is because the LED used by everyone is The Ф3 to Ф5 mm LED, which is most commonly used as an indicator function in the electronics industry, uses a simple electronic circuit to increase the current to increase its luminous intensity, but the LED only gains a brief high brightness, but it loses the life expectancy of the LED. Therefore, careful selection of LEDs in the design of semiconductor lighting fixtures should use high-power LEDs as the lighting source.
6) Increase luminous flux and reduce prices Currently, a single 1W LED device has a luminous flux of about 25 lm, a good quality price of more than 5 US dollars, and a poorer price of 3 US dollars. The luminous flux of 25 lm is too small for general illumination. The luminous flux of an ordinary 60 W incandescent lamp is greater than 700 lm, which means that in order to replace traditional lighting, multiple LED devices are required, plus a drive circuit and a lamp housing. Lamps, etc., such a high cost is the biggest problem of white LEDs in general lighting. In particular, the efficiency is currently 25 to 45 lm/W, which needs further improvement.
2. Technology Development Trend
1) Abandon the current LED lamps and lanterns are merely the design method of the traditional lamps and lanterns and LED luminous module, should fully consider LED optics characteristic, develop LED special-purpose lamps and lanterns.
2) The power supply and control circuit design, power supply to change the current widely used capacitive buck and impedance divider application mode, design a reasonable low current constant current source circuit, the use of clock cycle modulation in the drive current, improve LED lamp stability, while further improving the efficiency of the power supply.
3) In the control circuit circuit design, it is necessary to develop three aspects of centralized control, standard modularization, and system expandability.
4) In the current situation of limited LED light efficiency and luminous flux, give full play to the characteristics of LED color diversity, and develop control circuits for color-changing LED lighting.
5) Take advantage of LEDs to develop a lighting system that incorporates LED lighting and photovoltaic systems.
6) Develop an integrated flat light source system for indoor lighting. The trend is to integrate LED lighting fixtures with architecture.
7) Develop LED lamp simulation system to speed up product development.
8) Develop solar and high-brightness LED integration technologies to address the matching and control technologies of solar cell systems and LED lighting systems.
1, the main technical overview of semiconductor lighting system
1) The thermal management of a luminaire system is often referred to as a cold light source. This is because the principle of LED luminescence is that electrons emit photons directly after recombination without the need for a thermal process. However, due to the presence of Joule heat, LEDs emit heat while accompanied by heat, and for high-power and multiple LED applications, the heat quantity becomes less and less, LED is different from traditional lighting sources such as incandescent lamps and fluorescent lamps. Excessive temperatures can shorten or even terminate their service life. Moreover, the LED is a temperature-sensitive device. When the temperature rises, its efficiency drops sharply. Therefore, the system structure design and the development of the heat dissipation technology are also problems faced by the LED application. Since forced air cooling is often not desirable in light sources, heat sinks and other methods for enhancing natural convection cooling are playing an increasingly important role in the design of LED lamps and light sources as input power increases.
2) Enhancing color rendering Currently, white LEDs commonly use blue emitting LEDs to superimpose yellow-emitting YAG phosphors excited by blue light into white light. Since the luminescence spectrum contains only two spectra of blue and yellow, there is a problem that the color temperature is high and the color rendering index is low, which does not meet the general lighting requirements. The sensitivity of the human eye to chromatic aberration is much higher than the sensitivity to light intensity. For illumination, the color rendering of the light source is often more important than the luminous efficiency. Therefore, adding an appropriate amount of red emitting phosphor and maintaining high luminous efficiency is an important issue in LED white lighting.
3) The secondary optical design of the lamp system Traditional lamps have long used incandescent lamps and fluorescent lamp sources as the reference to determine the standard of the lamp's optics and shapes. Therefore, the LED lamp system should consider abandoning the assembly method of traditional lamps and LED lighting modules. Taking into account its optical characteristics, different lamps are specially designed for LED light sources. The optical system design content mainly includes the following aspects: 1 According to the requirements of the lighting object and luminous flux, the shape of the optical system, the number of LEDs, and the power are determined; 2 A plurality of LED light emitting tube combinations are designed as a point light source, a ring light source or The "secondary light source" of the surface light source calculates the illumination optical system according to the combined secondary light source. 3 It is very important to control the light distribution of each LED tube on the "secondary light source" that constitutes the illumination optical system.
Because the light beam emitted by the LED is concentrated, it is easier to control and does not require the reflector to collect light, which is beneficial to reduce the depth of the lamp. For example, using a planar mirror optics system, one or two LEDs can be used to illuminate a large surface, while the depth of the lamp is very thin; and using light guide technology, the LED is directly mounted beside the light guide, which can greatly reduce the light source and other components. Occupied by the volume, made of ultra-thin lamps.
4) Integration of power supplies, circuits, and luminaires. Designing luminaires for LEDs requires attention. One issue that incandescent and fluorescent luminaire designers rarely care about is the power supply. Most incandescent lamps are powered directly from the AC line, so no power is required. Fluorescent lamps use ballasts to complete the power function. However, LEDs need a dedicated power supply and driver circuit, and they should be considered when designing lamps.
The major characteristics of semiconductor lighting and solar power generation are environmental protection, energy saving, long life, and safety. The combination of solar power generation and semiconductor lighting to complete the conversion of photoelectric to electro-optic light is the best combination. Natural energy-utilizing independent semiconductor lighting fixtures that use solar battery power as a power source are energy-saving, environmentally-friendly, and long-lived. They also eliminate the related wires and supporting facilities and have a huge market space.
5) to improve the reliability of the system LED light source is called it longevity lamp, as a solid light emitting device, the theoretical life of more than 100,000 hours, its life is much longer than the traditional light source, so in some difficult to replace and maintain the occasion to use, Its maintenance costs can be greatly reduced. However, in many practical applications, this advantage cannot be seen. Instead, the user sees that the light fades badly and has a short life span. It takes only less than 10,000 hours to be broken. This is because the LED used by everyone is The Ф3 to Ф5 mm LED, which is most commonly used as an indicator function in the electronics industry, uses a simple electronic circuit to increase the current to increase its luminous intensity, but the LED only gains a brief high brightness, but it loses the life expectancy of the LED. Therefore, careful selection of LEDs in the design of semiconductor lighting fixtures should use high-power LEDs as the lighting source.
6) Increase luminous flux and reduce prices Currently, a single 1W LED device has a luminous flux of about 25 lm, a good quality price of more than 5 US dollars, and a poorer price of 3 US dollars. The luminous flux of 25 lm is too small for general illumination. The luminous flux of an ordinary 60 W incandescent lamp is greater than 700 lm, which means that in order to replace traditional lighting, multiple LED devices are required, plus a drive circuit and a lamp housing. Lamps, etc., such a high cost is the biggest problem of white LEDs in general lighting. In particular, the efficiency is currently 25 to 45 lm/W, which needs further improvement.
2. Technology Development Trend
1) Abandon the current LED lamps and lanterns are merely the design method of the traditional lamps and lanterns and LED luminous module, should fully consider LED optics characteristic, develop LED special-purpose lamps and lanterns.
2) The power supply and control circuit design, power supply to change the current widely used capacitive buck and impedance divider application mode, design a reasonable low current constant current source circuit, the use of clock cycle modulation in the drive current, improve LED lamp stability, while further improving the efficiency of the power supply.
3) In the control circuit circuit design, it is necessary to develop three aspects of centralized control, standard modularization, and system expandability.
4) In the current situation of limited LED light efficiency and luminous flux, give full play to the characteristics of LED color diversity, and develop control circuits for color-changing LED lighting.
5) Take advantage of LEDs to develop a lighting system that incorporates LED lighting and photovoltaic systems.
6) Develop an integrated flat light source system for indoor lighting. The trend is to integrate LED lighting fixtures with architecture.
7) Develop LED lamp simulation system to speed up product development.
8) Develop solar and high-brightness LED integration technologies to address the matching and control technologies of solar cell systems and LED lighting systems.
LED Down Light Features :
1. More efficient: LED Ceiling Light is more effective than traditional bulb. A 1W LED Bulb is equals to a 10W traditional bulb, 90% of the electrical power can be saved.2. Much safer: led down light generates little heat, apprightoximately 50 degree centigrade, much safer than traditional lamp which might generate heat up to 2000 degrees in its core.
3. Long Life-span: LED Ceiling Light has more than 50 thousand hours life span, 50 times more than the traditional lamp.
4. Environmental friendly: LED Ceiling Light will never produce red-infrared, ultra-violet or any other radial that might harm for human.
5. Easy Installation: Remove the quartz lamp cup, and reace the led down light cup. 1. High quality Constant-current power supply to keep it more stable and very low luminance decrease;
2. Pure aluminium material benefits for heat dissipation;
3. 50000hours lifespan three year warranty;
4. Wide range of beam angle is available: 30°/45°;
5. Direct Retrofit, Easy Installation;
6. Energy saving up to 80%, extremely low maintenance cost;
7. No heat UV or IR Radiation, No mercury,Instant start,Reduce CO2;
8.Adopt high brightness and low light decline led;
9.Well-design of thermal structure;
10.High efficiency constant current driver;
High brightness
LED Down Light
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FOSHAN OUHONG LIGHTING CO., LTD. , http://www.soelighting.com