LED lamp design problem solving


A problem in semiconductor lighting applications a heat […]

A problem in semiconductor lighting applications
a heat dissipation
b Lack of standards, bad products
c There are price and design quality problems, and the final consumer chooses led lighting, lacking confidence
d Semiconductor lighting is very different from traditional lighting in electrical design. Traditional lighting companies need an experience/skill accumulation process.
Everyone is optimistic about the market, but still no scale
(1) By adjusting the high-precision constant current chip, to ensure the consistency of LED brightness   color, standard   customized   reliable high-quality products are provided to downstream customers at the module level;
(2) New and old lighting design manufacturers, do not overly complicated electrical design, only need to add traditional constant voltage power supply to the external simple circuit design, is the fastest and most reliable way;
(3) Solve the technical and quality problems of the LED lighting market on a large scale.
Luming-LED panel light
2 Thermal design
a shortest heat transfer to the path, reducing heat transfer resistance;
b increase the mutual conduction area and improve the heat transfer rate;
c Reasonable calculation of design heat dissipation area;
d Effective use of heat capacity effect.
Output drive voltage selection:
(1) When the power supply is driven within 20W, it is more suitable for driving about 48V;
(2) The most suitable 36V power supply output voltage is most suitable;
(3) Most offline lighting is 12V and 24V.
(1) Consider appropriate drive voltage values ​​based on series and parallel safety, and maximize the voltage value to reduce the cost of power supply design specifications;
(2) According to safety regulations, product design must comply with certification requirements, with peak flow exceeding 42.4Vac or DC exceeding 60Vdc;
(3) Consider the technical and quality issues of large-scale processing in the LED lighting market.
3 most efficient back-end drivers
When the output voltage is about 48V, the constant current efficiency of the low dropout linear constant current device is as high as 99%, and the constant current accuracy is within ±3%, which is not affected by any peripheral devices; when the output voltage is about 36V, the low dropout linear The constant current efficiency of the constant current device is as high as 98.6%, and the constant current accuracy is within ±3%, which is not affected by any peripheral devices; even in the offline lighting section, the lower voltage of 12V and 24V have 96% and 98% efficiency, respectively; Efficiency is equal.
(1) The most effective driving constant current architecture;
(2) The highest precision constant current mode is least affected by peripheral equipment;
(3) Concise convenient practical.
The development of 4AC-DC design switching power supply is the result of years of accumulation. In the short term, AC-DC constant current cannot be broken. Constant voltage and constant current are the relationship between spear and shield. They must be considered separately. The load regulation rate of the constant current source is 1% (mA). )/V, the constant current effect is not reached; the more ideas, the higher the cost and the risk is proportional.
(1) It is the most economical to make reasonable use of existing switching power supply resources;
(2) The combination of constant pressure and constant current technology is inevitable;
(3) Creativity is effective in stable product technology.
5LED combination package is the future development trend
The combined design of the module can effectively reduce the cost of one-time packaging; the distributed packaging form is conducive to reducing the cost of heat dissipation design; the selection of domestic aluminum-based PCB board; convenient optical design; simplified power supply design; diverse packaging forms; force.
6 Encapsulation structure'abduction' our optical effect design
This is Cree  Nichia  Lumileds  OSRAM representative package.
7 Combination of modular packaging and constant current technology
Design LED packaging at the PCB board level, simple and cost-effective; everyone can brainstorm to develop different types of packaging forms; design products based on power LEDs, integrate constant current technology and light distribution parameters; effectively respond to changing   constantly changing LED lamp demand; the power supply part is only powered by the existing traditional switch constant voltage power supply; the product introduction speed is increased, the lamp design is simple and practical, and the cost is greatly reduced; and the patented leading edge LED package can be avoided.
8Package according to the nominal value of voltage
Innovative LED constant current drive technology was born in Shenzhen CYT. This technology is a direct integration of low-dropout linear high-precision constant current technology based on LED packaging technology; in the future, LEDs may appear directly with nominal voltage specifications, such as: 12V/1W, 24V/ 1W, 36V/1W, 48V/1W, 12V/3W, 24V/2W...36V/10W, etc. In the future, customers using CYT technology for product design will no longer need to consider any LED constant current issues, and can use the existing standard constant voltage power supply. This technology will declare the end of "LED constant current power supply"!