As high-power LEDs are commonly used in lighting decoration and lighting, power LED drivers are becoming more and more important. Driving high-power LEDs with utility power needs to solve the problems of buck and constant current, and also has relatively high conversion efficiency, small volume, long-term operation, low cost, electromagnetic interference and power factor.
In the field of LED lighting, to reflect the characteristics of energy saving and long life, the choice of LED driver is very important, there is no good driver matching, the advantages of LED lighting can not be reflected.
First, the driver needs to be suitable for the working characteristics of the LED
The high-power LED is a low-voltage, high-current driving device. The intensity of the light is determined by the current flowing through the LED. If the current is too strong, the LED will be attenuated. If the current is too weak, the LED will be affected. Therefore, the LED needs to be driven. Constant current power supply is provided to ensure the safety of high-power LEDs and achieve the desired luminous intensity.
The T220C350W series provides a pulsed constant current power supply. The frequency and duty cycle of the current pulse can be adjusted. The driver provides a constant current and is fully controllable, so the maximum current flowing through the LED can be adjusted according to the performance of the LED. To increase the amount of light emitted by the LED. Due to the pulsed power supply, the LED is in intermittent operation, extending the service life of the high-power LED. In addition, the driver is operated at a high frequency, and fully utilizes the afterglow effect of the phosphor in the LED, which not only does not have the phenomenon of light flicker, but also further improves the luminous efficiency of the LED. Therefore, the driver of the same type, the drive of the T220C350 series will increase the luminous flux of high-power LEDs.
Second, the volume is miniaturized
At any time, the further development of LED, the continuous advancement into the field of lighting, and the gradual popularization of the civilian market. The miniaturization of high-power LED power supply design is an inevitable trend, which poses a new topic for LED drivers.
The T220C350 series driver has a PCB board diameter of only 18.5mm and can be placed directly into the GU10's lamp holder. Packaged into a module with a volume of only 21.5X18mm, it can be placed directly into the lamp holder of E26 and E27. Currently, the series is capable of driving up to 12W of LEDs.
Third, multi-function protection
When the LED is too strong, it causes the LED to attenuate, resulting in a shortened life of the LED. Constant current is extremely important in LED lighting, which requires the driver to provide overcurrent protection. Good LED driver protection is essential. The T220C350 series driver has overcurrent protection, over temperature protection, short circuit protection and safety protection.
In some applications, over-temperature protection is especially important. Without this function, the higher heat generated by the LED causes the attenuation of the high-power LED. T220C350 series driver, when the LED temperature is too high, it will automatically adjust the current, reduce the amount of current through the LED, reduce the occurrence of higher heat, but will not cause significant changes in LED brightness, automatically adjust between heat and current A balance point, the role of the LED to protect, let the LED lamp work for a long time, thus extending the life of the LED.
The LED is a light-emitting diode, and when damaged, the entire LED is in a conductive and short-circuit state. When the high-power LED is abnormal, the T220C350 driver will be short-circuit protected, which will not cause fleas, and other electronic products will still work normally.
Fourth, electromagnetic interference
The T220C350 series driver has its own proprietary control chip, which solves the electromagnetic interference problem by relying on the related application of the chip. Can pass CE safety certification. The following is the AC input waveform of the T220C350 series driver. AC input waveform diagram for drivers of similar products.
Five, power factor
The power factor is the phase angle cosine between the voltage and current waveforms applied to the load (if the phase angle difference between the voltage waveform and the current waveform is φ, then cosφ is the power factor of the power supply). When the voltage and current waveforms applied to the load are in phase (ie, the phase angle difference is φ = 0), the power factor cos φ = 1 is ideal; when the voltage and current waveforms applied to the load have a phase angle difference of 90 ° When (ie φ = 90°), the power factor is equal to zero (at a minimum); usually, the power factor of the power supply is between 0 and 1, ie 0 ≤ cos φ ≤ 1, which can be expressed as a percentage.
One of the consequences of the phase difference between the voltage and current waveforms applied to the load is a reduction in power supply efficiency, i.e., the generation of the required power requires the input of more power. Another result is the more serious consequence, that is, the waveform difference between voltage and current produces too many higher harmonics. A large number of higher harmonics are fed back to the main input line (grid), causing the grid to be contaminated by higher harmonics and becoming a hidden danger of a vicious accident. At the same time, this higher harmonics can also disturb sensitive low voltage circuits in the control system.
With the deepening of the concept of energy saving, the development of high-power LEDs is becoming more and more mature. The indicators of “power factor†are also put forward by the LED power drive industry. The actual power in the AC system is equal to the apparent power multiplied by the power factor. At present, basically all power sources have power factor indicators. The power factor of China's traditional energy-saving lamps is 0.5, while the power factor of T220C350 series drivers is 0.625-0.75. Under the volume of 21.5X18mm, the power factor can be reached very much. difficult. With the further research of Tianxiaming Technology R&D personnel, the energy of the T220C350 series driver will continue to improve. It is expected that the power factor of the driver will reach 0.9 or so next year.
The T220C350 series driver is designed without an electrolytic capacitor, and all of them use high-precision ceramic capacitors, which increases the long life of the entire power supply.
Tianxiaming Technology will have more products for LED decorative lighting, and will be widely used in RGB LED and LED table lamps, LED spotlights and other fields. In the future, Tianxia Ming Technology will develop constant current 700mA and 1000mA drivers to meet the larger power LED driver.
We believe that with the development of high-power LEDs, the power drive design will also be promoted, and the design concept of the new LED driver will be further promoted. High-power LED replacement lighting will soon become a reality.
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Asia Leader Import & Export Co., Ltd. , http://www.nbflashlight.com