As a new light source, in recent years, major companies and research institutions have been in the ascendant in the research of LED power supply and driving circuit. The main function of the LED drive circuit is to convert the AC voltage into a DC voltage, and at the same time complete the matching with the voltage and current of the LED. As the power supply voltage of silicon integrated circuits plummets, the LED operating voltage is more and more in the optimal range of the output voltage of the power supply, and most technologies for powering low-voltage ICs are also suitable for powering LEDs, especially high-power LEDs. .
In order to improve the efficiency, the output voltage of the white LED driving charge pump that has been applied in recent years is no longer an integer multiple of the input voltage. The negative pressure charge pump white LED driver can switch the working mode of each channel separately, which significantly improves the working efficiency compared with the 1 times voltage/1.5 times voltage positive charge pump LED drive scheme. High efficiency is the overall energy saving requirement of LED drive system, and high efficiency of LED drive power supply is the foundation and guarantee of low temperature rise, long life and high reliability.
1. High efficiency, low temperature rise, long life.
If you choose a high-temperature electrolytic capacitor with a life span of 10,000 hours at 105°C, according to the popular electrolytic capacitor life estimation formula "every 10 degrees lowers, the life is doubled", then its working life at 95°C is 20,000 hours, and at 85°C The working life in the environment is 40,000 hours. For example, when the operating temperature of the Inventronics drive power supply is generally up to 70 degrees, and the temperature of the electrolytic capacitor is roughly controlled at about 85 degrees, the life can reach 40,000 hours. If it works for 12 hours a day, The life expectancy is nearly 10 years.
2. High efficiency, low loss, low temperature rise.
For example, an LED driving power supply with an output of 100W, when the efficiency reaches 95%, the loss is 5.2W, when the efficiency is***** 85%, the loss is 17.6W, the latter is 3.4 times the former, the experiment shows that under the same conditions, the former The temperature is 10~15℃ lower than the latter.
3. High efficiency, low temperature rise, and high reliability. With the decrease of the temperature of the led drive power supply and the improvement of the working environment of IC and power semiconductors, the MTBF (mean time between failures) will be significantly improved.
4. The increase of the temperature of the LED chip will lead to the change of the performance of the light-emitting device and the attenuation of the electro-optical conversion efficiency, and even failure in severe cases. Some experimental tests have shown that the luminous flux of the LED itself will decrease by 3% for every 5°C increase in the temperature of the LED itself.