According to media reports, Shenzhen LED industry achieved an annual output value of 24.5 billion yuan in 2009, and the average annual growth rate was over 30%. The market prospect is bright. Recently, however, there have been real comments in the media that “the industry is hot and the market is cold and shiveringâ€. The reason is that the price is the culprit. Here we analyze the possibility of declining prices from the LED street lamp products currently on the market.
The LED street light mainly consists of three parts: one is an LED light emitting device, the second is a driving power source, and the third is a lamp socket and the like. Lampholders and other structural components are currently very competitive in the market and prices are already very low. The high-quality light-emitting components are basically imported from the United States, Japan, Germany, South Korea, and Taiwan Province, and the price has also been reduced to some extent. For example, when a 350mA white LED was first introduced, the bid price was 6-10 US dollars. At present, it is possible to buy imported 350mA white LEDs at a purchase price of less than US$2.5. However, such components do not have pricing power and bargaining power at home, and price cuts can only be determined by foreign original manufacturers. So at present, to reduce the cost of LED lights, driving power is the only way. Here we come to understand the structure of the LED street lamp drive power.
The white LED must be driven with a constant current source so that the white light spot does not change (that is, the brightness must be uniform). In addition, since the white LED is a diode, its internal forward voltage drop (Vf) must be overcome. Vf varies with the current value of the white LED and also varies with temperature. In general, Vf of a 350mA white LED varies from 2.9V to 3.7V over the entire operating temperature range. Most applications use multiple white LEDs, and these LEDs can also be configured in parallel, in series, or in series and in parallel. This means that white LED driver ICs must be able to provide sufficient current and voltage for multiple LEDs of a particular configuration, and the voltage conversion topology used by this IC must meet both the input voltage range and the output voltage and current requirements.
Currently, on the market, a single LED circuit generally connects 10-20 LED lamps in series, and the entire street lamp requires 4-20 series circuits. In order to ensure that the brightness of the LED in each loop is the same, there will be no bright and dark side of the same street light. The drive power supply must have a dedicated section to ensure that the street light circuits have constant current. So currently on the market mainstream LED street lamp driver power supply consists of two parts, one is a constant voltage source, will be the mains rectifier, converted to a stable DC, part of the constant current source, to ensure the brightness of each street lamp.
In order to reduce street lighting manufacturer cost pressures. Recently, the CLP Huaxing Technology R&D team has conducted long-term technical research and testing, and has officially launched a full-line, single-channel, multi-channel (up to 20) output constant-voltage, constant-current integrated isolation waterproof LED street light power supply based on a two-stage drive solution. The module product, the volume remains unchanged, and mass production has been achieved.
This kind of LED driving power source encapsulates the isolation module, switching power supply and constant current module in one module. It adopts the exclusive patented technology of China Power Huaxing, and the constant current output can choose 350mA, 700mA or other values ​​in a single way. All products pass 8000KV surge voltage test. The new product introduces voltage and current feedback control, users can change the load LED array form and number of LEDs according to need, and get different output power. Through practical tests, the power supply overcomes the color change of LED lights due to input voltage, ambient temperature and other factors, the power factor reaches 0.95 or more, the life can reach more than 50,000 hours, and the three-year warranty is provided with overvoltage and overcurrent protection functions. .
After cost calculation, the cost of this series of products is reduced by 30% compared with the two-level products.