1. LED light source high luminous efficiency
Luminous efficiency comparison: incandescent lighting effects in 10-15lm, tungsten halogen lighting efficiency of 12-24 lumens / watt, fluorescent lamps 50-90 lumens / watt, sodium lamp 90-140 lumens / watt, most of the power consumption into heat loss.
LED light effects: can be sent to 50-200 lumens / watt, and the light is good monochromaticity, narrow spectrum, without filtering, can emit colored visible light directly.
2. LED light source consumes less power
LED single-tube power 0.03-0.06 watts, using DC drive, single-tube drive voltage of 1.5-3.5 volts. The current of 15-18 mA reflects the fast speed and can be operated at high frequency. In the case of the same lighting effect, the power consumption is one ten thousandth of that of the incandescent lamp, and the half of the fluorescent tube, which Japan estimates, if adopted Light efficiency is twice as high as that of a fluorescent lamp. It replaces half of Japan's incandescent and fluorescent lamps, saves an equivalent of 6 billion liters of crude oil per year, and has the same effect as a fluorescent lamp of more than 40 watts, while the power consumption of each LED is only 18 watts. .
3. Long life LED light source
Incandescent lamps, fluorescent lamps, and tungsten halogen lamps are characterized by the use of electronic light field radiation, filament burning, thermal deposition, and light attenuation. LED lamps are small in size and light in weight, and are encapsulated in epoxy resin to withstand high-strength mechanical shocks. Vibration, not easy to break, the average life expectancy of 3-5 million hours, LED lamp life of up to 3-5 years, can greatly reduce the maintenance costs of lamps to avoid the constant light of the pain.
4. Safe and reliable
Low calorific value, no heat radiation, cold light source, safe collision, accurate control of light type and luminous angle, light color, no glare, no mercury, sodium and other substances that may harm health.
5. LED light source is environmentally friendly
LED is a solid-state light-emitting body, impact-resistant and not easily broken, waste can be recycled, there is no pollution to reduce a large number of harmful gases such as sulfur dioxide and nitrides, and the production of greenhouse gases such as carbon dioxide to improve people's living environment, can be called "green lighting."
Currently, there are three types of white LED technology: one is the use of the principle of three primary colors and three kinds of ultra-high brightness LEDs of red, green, and blue that can be produced are mixed in a ratio of light intensity of 3:1:6 to form white, two kinds, and super Highly InGan blue LED, the tube with a total of a little plutonium-based phosphor, it can generate yellow-green light under the excitation of blue light, and this yellow-green light can synthesize white light with the blue light, three kinds can not make ultraviolet The light LED uses a UV-excited three-color phosphor or other phosphor to generate white light that is a mixture of multiple colors.
6. LED light source is more energy-efficient
Of course, energy saving is the most important reason for considering the use of LEDs. Maybe LEDs are more expensive than traditional light sources, but with one year's energy saving to recover the investment of light sources, we can obtain several times of annual energy saving net collection period in 4-9 years.
life
Constant current source driving is the best LED driving method. It adopts constant current source driver and does not need to connect the current limiting resistor in series in the output circuit. The current flowing on the LED is also not affected by external power supply voltage change, ambient temperature change, and discreteness of LED parameters. Impact, so that we can maintain a constant current, give full play to the excellent features of LED.
The LED constant current power supply is used to power the LED lamps. Since the current flowing through the LEDs is automatically detected and controlled during the power supply operation, there is no need to worry about excessive current flowing through the LEDs when the power is applied. Bad power supply.
Lamp housing
LED lights have high efficiency, environmental protection and long life. However, people who use LED lights will find that, due to the large brightness of the LED, it is easy to make light energy into heat, making the LED light very hot. At this time, if the LED or the like is not able to dissipate heat as quickly as possible, its life will be greatly reduced.
Many LED manufacturers use aluminum housings for LED lamps. The aluminum shell is easy to dissipate heat, the appearance is exquisite, the weight is light, many high-end electronic products use the aluminum shell. For example, Apple's Apple laptop "Mac Pro" high-end computer series products use an all-aluminum shell, easy to notebook cooling, so that the computer does not even have to install the fan.
LED aluminum housing can increase the life of the wick, so that the LED lamp looks beautiful. However, aluminum lamp cups are relatively expensive to make and the production cost is very high. Lamp cups need to be machined using lathes. Therefore, some high quality, medium quality LED lights will use aluminum housings.
Another common LED lamp housing is a plastic housing. Due to the low cost of plastic shells, some low-end LED fixtures use plastic shells. However, plastic shells do not easily dissipate heat, and plastics easily melt and sublimate to produce harmful gases when exposed to heat. Therefore, plastic enclosures are not used in Europe, North America and Japan. Due to large-scale demand for inexpensive LED lamps in some parts of the country, there is a large amount of plastic housing sold in China.
Household lights
Many LED lights can replace spiral-type hot-bulbs or energy-saving light bulbs, from 5-40 watts, low-power hot-firing lamps, to 60 watts (only about 7 watts of electricity). As of 2010, some lamps can even replace higher-powered light bulbs. For example, a 13-watt light bulb is similar to a 100-watt incandescent light bulb. (General heat-firing lighting performance standards, about 14 to 17 lumens/watt, depending on the size and voltage. According to EU standards, an energy-saving light bulb equivalent to a 60-watt incandescent lamp, at least Can output 806 lumens.)
Most of the LED bulbs are designed not to be dimmable, but some also work with dimmers and have narrow illumination angles. Starting in 2010, these light bulbs began to fall in price from 30 to 50 US dollars. The LED light bulb is more energy efficient than the power saving light bulb, and has a life expectancy of up to 30,000 hours if properly radiated. Hot-glow lamps generally have a lifespan of only 1,000 hours, and power-saving light bulbs have only about 8,000 hours. Therefore, LED bulbs can be used for about 25 to 30 years, and the luminosity decays little with time. The Energy Star standard stipulates that after 6,000 hours of lamp use, the attenuation of light shall be within 10%, and the worst may not exceed 15%. Unlike fluorescent lights, LED bulbs are mercury-free. LED bulbs also have different color options. Although the price is higher, the power and maintenance costs are lower and can be offset.
Special Purpose
White LED bulbs are highly efficient and have a leading position in low-power markets (such as flashlights, solar garden lights and pedestrian street lights, bicycle lights, etc.). Monochromatic LED lights are commonly used to make traffic lights and holiday lighting.
In 2010, LED lights became a hot topic in the horticultural industry and agriculture. NASA took the lead in planting LED lights in space, followed by home and commercial indoor gardening. These specially designed lights are specially designed, and their light waves are just the wavelengths absorbed by chlorophyll, which promotes growth and also reduces light waves that plants do not absorb, resulting in waste. In the visible spectrum, photosynthesis requires only red and blue colors, so these lamps are designed with both colors. Compared with similar products, these LED lamps can provide the same photometric, no ballast, and heat much less than gas discharge lamps, suitable for indoor planting. Less heat can reduce evapotranspiration, thereby reducing the number of irrigation. Because of this, when using these planting lights, the plants should not be overly impregnated.
Purchase guide
1. Purchase LED lights with "Three Guarantees" commitments, and purchase lamps with CCC certification marks;
2, depends on the LED lighting product identification is complete, formal products should be identified;
3, see LED light power cord whether there is CCC safety certification mark;
4, to see if the lamp charged body exposed, the light source into the lamp holder, the finger should not touch the live metal lamp;
5, see the LED chip is accurate, the lens or the screen is worn.
Cause of damage
1. The voltage of the current is not stable, and the power supply voltage rises are particularly likely to cause the destruction of the LED lamp. There are many reasons for the sudden increase in the voltage. The quality of the power supply, or improper use of the user may cause the power supply voltage to rise suddenly. high.
2. Part of the lamp's power supply path is short-circuited. This is usually caused by a component in the line, or a short circuit in other lines increases the voltage at this point.
3. It is also possible that the LED is damaged due to its own quality and thus forms a short circuit, and its original voltage drop is transferred to other LEDs.
4. The cooling effect of the lamp is not good, we all know that the lamp is a heat-dissipating process. If the temperature inside the lamp is too high, the characteristics of the LED will be easily deteriorated. It is also easy to damage the LED lights.
5. There may also be water in the lamp because the water is conductive, which will short circuit the lamp.
6. The anti-static work was not done during assembly, so that the interior of the LED has been damaged by static electricity. Although the normal voltage and current values are applied, it is extremely easy to cause LED damage.
Common Causes and Treatments of LED Blinking
Normally the human eye can perceive light flicker at frequencies up to 70 Hz. Above this frequency, it is not perceived. Therefore, in LED lighting applications, if the frequency of the pulse signal is lower than 70 Hz, the human eye will experience flicker. Of course, there are several factors that can cause LED lights to flash in a specific application. For example, in off-line low power LED lighting applications, a common power topology is an isolated flyback topology. For an example of an 8W off-line LED driver GreenPoint® reference design that meets the "Energy Star" solid-state lighting standard, the sinusoidal square-wave power conversion of the flyback regulator does not provide constant power to the primary bias, dynamic self-powered (DSS) ) The circuit may activate and cause light to flicker. To avoid this problem, the primary bias must be allowed to discharge in each half-cycle, and accordingly the capacitance and the resistance of the bias circuit must be properly chosen.
In addition, electromagnetic interference (EMI) filters are required even in LED driver applications that provide excellent power factor correction and support TRIAC dimming. The transient current caused by the TRIAC step can excite the natural resonance of the inductor and capacitor in the EMI filter. If this resonant characteristic causes the input current to fall below the TRIAC holding current, the TRIAC will shut down. After a short time delay, the TRIAC usually turns on again, inducing the same resonance. In one half cycle of the input power waveform, this series of events may be repeated several times, resulting in visible LED flicker. In order to deal with this problem, a key requirement of TRIAC dimming is that the input capacitance of the EMI filter is extremely low, and this capacitor must be able to be decoupled through the TRIAC and the winding impedance. According to the formula, if the capacitance in the dimming module is reduced, the resistance of the resonant circuit can be increased, and in principle the oscillation is suppressed and the desired circuit operation is restored.
