LED has developed rapidly in various application fields in recent years, because it has no toxic substances, is environmentally friendly, has a long service life, and has high optical efficiency. In theory, the service life of LED is about 100,000 hours, but in the whole application process, some LELED lighting designers do not know enough about LED driving switching power supply or use it unreasonably, and the conclusion greatly shortens the service life of LED lighting products.
Due to the uniqueness of LED production, processing and production, the current and operating voltage characteristics of LEDs produced by different manufacturers and even the same manufacturer in the same batch of products have great individual differences. Taking typical 1W white light LED specifications and models as an example, according to the change trend of LED current and working voltage, it is briefly explained that 1W white light generally adopts a positive working voltage of about 3.0-3.6V. In order to ensure the service life of 1WLED, the general LED manufacturer recommends that the lighting factory use a current of 350mA to drive. When the forward current on both sides of the LED reaches 350mah, the forward working voltage on both sides of the LED will not increase much, which will greatly increase the forward current of the LED to increase the LED bulbs, making the LED ambient temperature into a parallel line, thereby accelerating the LED light. damage, reducing the service life of the LED. Due to the uniqueness of LED’s operating voltage and current changes, the switching power supply that drives LEDs is strictly managed.
LED drive switching power supply is the basis of LED lamps. It’s like a human brain. To manufacture high-quality LED lamps, the constant-voltage approach to driving LEDs must be abandoned.
At this stage, for LED light products produced by many manufacturers (such as protective fences, lamp cups, projection lamps, lawn lamps, etc.), select resistors, reduce blood pressure, and then add a Zener diode Zener tube to the LED power supply system, so as to promote the LED’s The method has great disadvantages, first of all, it is inefficient, consumes a lot of electromagnetic energy on the step-down resistor, and may even exceed the electromagnetic energy consumed by the LED, and cannot drive large currents. Because the higher the current, the more power is dissipated on the step-down resistor, there is no guarantee that the LED current will not exceed its normal operating standard. When designing a product, choosing to reduce the two DC voltages of the LED to drive the power supply system is the biggest advantage of abandoning the LED chromaticity. Select the resistance, the method of lowering the blood pressure to push the LED, the screen brightness of the LED cannot be stable. When the power supply voltage of the power supply system is low, the chromaticity of the LED is darker, and when the power supply voltage of the power supply system is high, the chromaticity of the LED is high, and the chromaticity of the LED is high. Naturally, the method of lowering blood pressure is the biggest advantage of lowering the cost value.
Post time: Jul-28-2022