Summary
The global focus on low-power and high-efficiency technologies continues. As lighting applications account for nearly 20% of the world's power consumption, advances in lighting technology can have a huge impact on energy conditions. LED solid state lighting (SSL) is an environmentally friendly technology with excellent form factor, long life, high conversion efficiency and 80% or 90% lower power consumption than conventional incandescent bulbs. In LED SSL, the LED driver plays an important role because it relies on it to provide the exact current needed to maintain a steady brightness. However, conventional LED driver solutions use secondary feedback circuits to drive the voltage and current of the LEDs, while secondary feedback circuits result in increased cost and size. This article will introduce a patented "Primary Side Regulation" (PSR). This PSR controller eliminates the need for a secondary side feedback circuit that precisely adjusts the voltage and current of the LED driver in the primary side of the transformer. It also includes frequency jittering to reduce EMI and light-load standby mode to reduce standby loss. With this solution, the PSR charger can achieve smaller form factors, lower standby power consumption and higher efficiency than traditional designs such as Ringing Choke Converter (RCC) and traditional PWM.
LED lighting overview
Energy-saving green technologies are becoming more and more important due to imbalances in energy demand, increased energy costs, and global concerns about environmental issues. Energy consumption in lighting applications can be as high as 20%, so using innovative technologies to reduce energy waste has a major impact on energy efficiency. Energy efficiency regulations are becoming more common in all regions of the world. For example, the United States has ENERGY STAR®, and Australia, the European Union and California have announced that they will phase out traditional lighting solutions.
The light-emitting diode (LED) is actually unidirectionally conductive like the rectifying diode. Unlike traditional lighting technology, SSL LEDs use semiconductors to convert electrical energy into light energy. The advantages of LED lighting over traditional technology are as follows:
1. The LED is driven by a DC voltage to maintain high brightness even under low voltage and low current conditions. In the same lighting application, LEDs can save up to 80% compared to other lighting solutions. High-brightness LEDs can last as long as 60,000 to 100,000 hours; incandescent bulbs are only 1,000 hours. In addition, LEDs react quickly (100ns ~ 1ns).
2. The monochromaticity of the LED is good. Common colors include red, green, yellow and orange. Its color can be changed by changing the current, and unlike traditional cold cathode fluorescent lamps (CCFLs), LEDs do not contain ultraviolet and infrared radiation in the spectrum, and harmful mercury metal elements are also less, which is environmentally friendly.
3. LEDs are small in size, resistant to vibration, and have high impact resistance. They can also be made into various shapes in the bulb.
Compared with LEDs, spiral energy-saving bulbs and T5 fluorescent lamps, incandescent bulbs have an illumination efficiency of only 12 lm/W and a lifetime of less than 2,000 hours; spiral energy-saving bulbs have an illumination efficiency of 60 lm/W and have a lifespan of approximately 8,000 hours; while T5 bulbs have a lifetime of approximately 8,000 hours. The lighting efficiency is 96 lm / W, and the life expectancy is about 10,000 hours. The 5mm white LED has an illumination efficiency of 20 to 28 lm/W and a lifetime of approximately 100,000 hours. Clearly, LEDs have a longer life and more attractive features than traditional lighting applications. High-Brightness Light Emitting Diode (HBLED) is a high-power, high-brightness LED that has a longer life, smaller size, and flexible design. It has become a replacement for traditional incandescent bulbs and halogen lamps. . HBLED is generally used in the following applications:
1. Screen display and traffic lights: various billboards, sports scoreboards and traffic numbers.
2. Automotive lighting: dashboard indicators, audio and external LED brake lights, tail lights, side lights, etc.
3. Backlight: Backlighting of cell phones, digital cameras and notebooks.
4. Landscape lighting, architectural lighting, decorative lights, street lights and residential lighting.
As a new type of LED lighting source, HBLED is bound to become a new trend in the future.