LED driver development review

[Source "High-tech LED - Technology and Applications" March issue Jiang Delai / Yao Xiaoli]


As the energy crisis and climate warming become more and more serious, energy conservation has become a topic of global concern. Lighting is an important aspect of human energy consumption, accounting for about 20% of the world's total energy consumption. Therefore, research on green energy-saving lighting has received more and more attention. Light Emitting Diode (LED) is a semiconductor light-emitting device that converts electrical energy into light energy. As a new high-efficiency solid-state light source, LEDs have miniaturization, low power consumption, long life, environmental protection, and color. Rich, fast response, high efficiency and energy saving. At the same brightness, the power consumption is only one tenth of that of ordinary incandescent lamps. LED lighting has become the focus of attention in the field of lighting. The incalculable potential of the LED lighting market is bound to ignite the huge demand for energy efficient LED drivers.

Development of LED drive technology

LEDs are used in a combination of connections, serial, parallel, and series-parallel combinations. The series mode can achieve natural current sharing, but the reliability is low. One of the LEDs fails to open, and the whole lamp will fail. At the same time, for high-power applications, the driving voltage will be high and cannot meet the SELV voltage requirements, which will increase the insulation requirements of the lamps and increase the system cost. Parallel use reduces the drive voltage and meets the SELV voltage requirements, but requires current sharing, and the total output current is high and the drive conversion efficiency is low. Therefore, in practical applications, for small power, there are many in series. For medium and large power, choose the combination of series and parallel to achieve a balance between conversion efficiency and reliability.

The following focuses on multi-channel constant current drive techniques for serial-to-serial combination. The multi-channel constant current driving technology has experienced the scheme of constant voltage driver plus multiple constant current driver, multi-channel constant current driver and adaptive driver.

1). Single AC/DC constant voltage driver plus multi-channel DC/DC constant current driver

The traditional switching power supply is mostly based on constant voltage output. When the LED industry is just starting, it chooses AC/DC constant voltage power supply, with the current limiting module or non-isolated DC/DC constant current module. Because it is a non-integrated design, there will be performance matching and EMC compatibility issues when selecting, system efficiency is not optimized, and procurement and maintenance costs are also high.

2). Typical multi-channel constant current driver

The circuit uses PFC stage, isolated DC/DC constant voltage conversion stage and DC/DC constant current three-stage circuit (as shown in Figure 2). The integrated design allows the parameters to be optimized, and the overall efficiency of the LED driver is improved. However, since the three-stage circuit is still used, the efficiency is further limited. Secondly, the three-stage circuit increases the complexity of the circuit, which reduces the reliability of the driver to a certain extent and directly affects the service life of the LED lamp. Third, the use of three-level circuits has increased the material cost and manufacturing cost of the driver, and has become a paradox for the rapid development of LEDs.

For more information, please refer to the March issue of "High-tech LED-Technology and Applications" magazine

Three-axis Smartphone Stabilizer is composed of pan axis, rolling axis and tilt-axis. With a gyro-stabilized gimbal system, it keeps stabilized or steerable horizon with automatic calibration to give you an unprecedented smooth shooting experience.

 3 axis stabilizing hanheld gimbal

Three-Axis Smartphone Stabilizer is born for video lovers. it stabilizers the video footage horizontally, without sacrificing the thrill of dynamic motion in the video.

 iphone gimbal stabilizer

Wewow focusing on handheld stabilizer is a technology company which does R & D independently. With Wenpod series product released, the company achieved the industry's praise and quickly became the leader of the smart stabilizer industry.


Our service


1. Reply to you within 24 hours.


2. Already sample: within 1-2days.


3. Shipping date: within 24 hours once get the payment.


4. 12 months warranty.


5. After-sales service, solve within 3 working dates.

If you have any questions, please contact with us directly.

Wewow appreciates domestic and international business relationship!

Three-axis Smartphone Stabilizer

Three-Axis Smartphone Stabilizer,3 Axis Handheld Gimbal For Smartphone,Smartphone Gimbal For Cell Phone,Three-Axis Stabilizer For Smartphone

GUANGZHOU WEWOW ELECTRONIC CO., LTD. , https://www.stabilizers.pl