Compared with the traditional lighting method, LED lighting has many unique places, mainly in the following: from the structural point of view, the traditional lighting source and the luminaire are separated, and the LED lighting can realize the integration of light distribution, heat dissipation and lamps in the structure. Functional design; from a functional point of view, only a small part of the traditional lighting can achieve dimming, and LED lighting can not only achieve brightness adjustment, but also achieve color and color temperature adjustment. In addition, LED lighting is more suitable for intelligent and digital control than traditional lighting methods, forming a complex lighting system.
Based on these characteristics of LED lighting, three models can be given, which are for the general illumination of LED, the intelligent control of LED lighting, the combination of LED lighting and solar wind energy, and illustrate some applications of electronic information technology in LED lighting.
Model 1: Power + Light Source
The working essence of modern electric light sources is to convert electrical energy into light energy, accompanied by a certain heat dissipation. Therefore, the LED general illumination model includes only the power supply and the light source. Under this model, only the switch control of the illumination can be realized, and the functions of dimming, communication, feedback, etc. of the illumination cannot be realized.
The power supply specifically refers to an AC-DC constant current type switching power supply. AC-DC refers to AC to DC conversion because the LED is actually a semiconductor diode that operates at DC voltage. Another characteristic of LED is that its working current approximation is an exponential function of the working voltage. A small fluctuation of voltage will cause a huge change of current. In severe cases, it will directly burn the LED. Therefore, to ensure the safe operation of the LED, the operating current must be constant. . Usually, the power supply of household appliances is constant voltage, and the characteristics of LEDs determine that it uses a constant current power supply. In order to improve the reliability of LED operation, we generally use an isolated switching power supply to achieve effective isolation between the LED and the utility grid. Corresponding to the switching power supply, there is also a type of linear power supply, which is rarely used now, because the switching power supply is more advantageous in terms of efficiency and volume. The current switching power supply technology can achieve a conversion efficiency of 85% or higher, a power factor of 0.95 or more, and a total harmonic of less than 15%. These indicators are also the basic requirements for our choice of switching power supplies.
The light source is the LED chip , which is the core component of LED lighting. In addition to electrical parameters such as operating current, tube pressure drop, etc., we are more concerned about its optical indicators, such as luminous flux, light efficiency, color temperature, color rendering index, light decay and so on. The optical performance of LEDs is closely related to their temperature. The increase in temperature causes problems such as reduced light efficiency, color temperature drift, and reduced lifetime. Therefore, heat dissipation technology is especially important in LED lighting.
Thermodynamics tells us that there are only three ways to dissipate heat from objects: conduction, convection, and radiation. Since the LED chip is only fixed to emit visible light of a certain wavelength, there is no infrared radiation to dissipate heat. In the LED, it is mainly conduction heat dissipation, accompanied by a certain convection heat dissipation. Reducing the thermal conduction of LEDs and reducing the thermal resistance of each link, if necessary, using forced air cooling, are all considerations in thermal design.
Model 2: Power + Control + Light Source
Model 2 has one more control module than the model, which greatly enriches the function of LED lighting. If the model is a lighting product, then model 2 can be said to be a lighting system. Since the control module is added, the power supply becomes a constant-voltage switching power supply, but the operation of the LED light source still requires a constant current power supply. This part (constant current drive) is implemented together in the control module. Below, we focus on the control system of LED lighting.
Long life, large capacity and good shock resistance, Low self-discharge and good discharge performance at low temperature, Strong charging acceptance and quick-charging capability, strong over-discharge resistance and charge retention, Maintenance-free and no acod or water for maintenance in usage, Excellent large current discharge performance, and have obvious advantages in startup and climbing, Environmental friendly, Lighter weight and smaller size.
Abl Battery,Lithium Battery,Rechargeable Lithium Battery,Motor Lithium Battery
Delight Eco Energy Supplies Co., Ltd. , http://www.cndelight.com