To design product, must first determine who LED encapsulation structure; Then consider how to adapt to these packaging form; By the we don't have much choice, optical structure is built on the encapsulation; We have many ideas can't play very well.
First, the problems existing in the semiconductor lighting application
1, The heat dissipation.
2, Lack of standards, the products are good and bad are intermingled.
3, Price and design quality problems, and ultimately consumers choose LED lighting, lack of confidence.
4, Semiconductor lighting in electrical design aspect, and there was a big difference between traditional lighting, lamps and lanterns of traditional enterprise needs to experience/skills accumulation process.
5, Everyone is bullish on the market, but there's no size on the quantity.
1, By adjusting the high-precision constant current chips, ensure the consistency of the LED brightness, chroma, at the module level provide standard and customized for downstream customers, reliable quality products;
2, The old and new lamps and lanterns design factory, don't be too complex electrical design, only need to add the traditional constant pressure at external power supply to work without the simple circuit design, is the fastest and most reliable way;
3, Solve the LED lighting market on massive amount of technical and quality problems.
Second, the heat dissipation design
1、The heat to the path of the shortest, reduce the heat conduction resistance;
2、Increase mutual conduction area, increase the heat to speed;
3、Reasonable calculated design cooling area;
4、Effective use of thermal mass effect.
The output driving voltage options:
About 20w grid driver within 48v more appropriate;
Large power grid driver output voltage is 36v around the most appropriate;
An off-line lighting most is 12v and 24v voltage.
Based on series-parallel safety load suitable driving voltage value, as far as possible a unified voltage value, reduce the cost of power supply design specification;
Based on the safety regulations, the product design should conform to the requirements of the certification, the peak flow more than 42.4 Vac or dc over 60 VDC voltage;
From solving the amount in the LED lighting market large-scale technical and quality issues to consider.
Three, highest efficiency back-end drive mode
When at about 48 v output voltage, low dropout linear constant current constant current device efficiency is as high as 99%, constant current accuracy within + / - 3%, is not affected by any peripheral devices; When around 36 v output voltage, low dropout linear constant current device, constant current efficiency is as high as 98.6%, constant current accuracy within + / - 3%, is not affected by any peripheral devices; Even in an off-line lighting, low voltage 12 v and 24 v, efficiency is 96% and 96% respectively; Power size efficiency are equal.
The most efficient drive constant current architecture; The highest precision constant current mode, minimal affected by peripheral devices; Concise, convenient and practical.
Four, the design of AC - DC
Until today in development of switch power supply is the result of years of accumulation, in the short term AC - DC constant current directly do not break; Constant voltage and constant current is the relationship between the spear and the shield, must be considered separately; Constant current source load adjustment rate is 1% (mA)/V, short of constant current effect; Ideas, the more cost is higher, is proportional to the risk.
Should reasonable use of existing resources, switch power supply is one of the most economic;
Constant voltage and constant current technology is inevitable;
On the stability of product technology creativity is effective.
Compared with switch constant-current method.