I finally got to know the LED bulbs, it’s too comprehensive!

LED bulbs are actually corresponding to incandescent lamps. It is very easy to understand. LEDs can be collectively referred to as LED bulbs. LED bulbs are one of the most widely used LED lighting products for commercial and residential use, and the market capacity cannot be underestimated.

LED bulb composition

Main parameters of LED bulbs

1. Color temperature: Conventional color temperature: warm white light (WW) 2700-3200k, natural light (NW) 4000-4500K, positive white light (PW) 6000-6500K, cool white light (CW) 7000-7500k [here cold white light difference and jewelry light The cool white light, the cool white light of the jewelry lamp is generally 15000-20000K. In addition, red, green, blue and other single color beads can also be done.

2. Power: The general power of LED bulbs is below 12W. Common LED bulb power is divided into: 3w, 4w, 5w, 6w, 7w, 8w, 9w, 10w.

3. Voltage and current: Voltage and current are also important parameters of LED bulbs. The grid voltages of different countries in the world and the voltages used in some occasions are different. Commonly used voltages are 12v, 110v, 220v, 85v-265v. The current is divided into input current and lamp current. First: input current: can be tested with the power supply, different power is not the same, the instrument is subject to. Second: lamp current: Generally, the high power is between 300mA and 320mA. The current has a great influence on the light decay of the LED lamp, so the stability of the current is also important. The lamp current and voltage cannot be given too much, otherwise it will seriously affect the life of the LED lamp.

4, light efficiency: light efficiency is also a very important factor of LED bulbs. At present (August 2013), the efficacy of the lamp beads of Nichia and Cree is generally about 150-0Lm/W. [The light efficiency of the test in the laboratory environment is not considered here. At present, (the highest luminous efficiency of the laboratory published by Cree is 276Lm/W as of 2013-May). At present, the light effect of the domestically used Taiwanese lamp is basically 100. -130Lm/W up and down.

5. Luminous flux: Luminous flux is mainly determined by the efficacy and power of the LED bulb. The following figure shows the physical map of the test luminous flux:

6, illuminance: illuminance, general lighting designers will consider more, in general, we consider very little. The unit of illuminance is lux, the English is Lux, and can now also be abbreviated as Lx. The luminous flux of 1 Lm is evenly distributed on the surface of 1 square meter. The illuminance is usually measured by illuminance meter. The illuminance meter is simple to use and the purchase cost is cheap. When there is no integrating sphere system, it can be measured by illuminance meter as some reference. . As shown above.

7, light decay: light decay in popular terms, is the brightness of the bulb after a certain period of time, the brightness decreased. The main factors affecting the LED light decay are heat dissipation and current. The current is unstable, the heat dissipation effect is poor, and the light decay is very serious. If the LED bulb uses an isolated constant voltage + constant current LED driving power supply and a car aluminum lamp housing to dissipate heat, the light decay is controlled within 2 inches.

8, color difference: color difference is the color temperature inconsistency, generally warm white light (2700-3200k) will take into account the color difference. Warm white light is the yellow light we usually say. Sometimes we buy two energy-saving lamps of the same brand and the same power and yellow light. When lighting in the same environment, we will find that one light color is brighter and one light color is darker. This situation is the color difference. In some cases, chromatic aberration is absolutely not allowed.

9. Color rendering: The degree to which the light source appears to the color of the object itself is called color rendering, which is the degree of color fidelity; the color rendering of the light source is indicated by the color rendering index, which indicates that the object is lighter than the reference light. (Sunlight) The deviation of color during illumination can reflect the color characteristics of the light source more comprehensively. Light sources with high color rendering perform better for color, and the color we see is close to natural color. Light sources with low color rendering have poor color performance, and the color deviation we see is also large. The International Commission on Illumination CIE sets the color rendering index of the sun to 100, and the color rendering index of each type of light source is different, such as: high color sodium lamp color rendering index Ra=23, fluorescent tube color rendering index Ra=60~90. There are two kinds of color development: faithful color development: the color of the original color can be correctly expressed. The light source with a high color rendering index (Ra) is used, and its value is close to 100, and the color rendering property is the best. Effect color development: To emphasize the specific color clearly, the beauty of life can use the additive color method to enhance the color rendering effect.

10. Glare: Objects with extremely high brightness or strong contrast in the field of view can cause visual discomfort called glare. Glare is an important factor affecting the quality of lighting.

11. Service life: LEDs can be used for more than 50,000 hours in general instructions, and some manufacturers claim that their LEDs can operate for about 100,000 hours. The main problem in this regard is that LEDs are not simply no longer functioning, and their rated service life cannot be calculated using traditional luminaire measurements. In fact, when testing the life of an LED, no one stays aside waiting for it to stop working. However, there are other ways to measure the lifetime of the LED. LEDs last because they don't cause filaments to blow. The LED does not stop working directly, but it gradually degrades over time. It is predicted that high-quality LEDs can maintain more than 60% of the initial brightness after 50,000 hours of continuous operation. Assuming the LED has reached its rated service life, it may actually be still emitting light, but the light is very weak. In order to extend the life of the LED, it is necessary to reduce or completely dissipate the heat generated by the LED chip . Thermal energy is the main reason why LEDs stop functioning.