日期：2012年5月7日

Filament lamps should not be replaced by super high power LED though power consumption judgment (2)

LED lighting technology is enjoying a rapid development. 15 years ago, a LED street light with a power consumption of 1 watt can only sent out lights of 30lm. 15 years later, a one-watt LED light can have a luminous flux around 100lm (super high power LED). While a 15-watt filament lamp have a luminous flux about 180lm. The development of LED is so fast that it is really hard to replace a 15-watt filament lamp by a LED light with fixed power consumption. On the other hand, power consumption is a parameter used to present electrical energy converting conditions. LED components with high electrical energy converting ability can have a higher luminous flux only consuming very little power.

 

Filament lamps should not be replaced by super high power LED though power consumption judgment

 

Luminous flux, optical spectrum is photometric data typically used to present lighting effects. Why people choose to use power consumption to present the brightness of traditional lamps instead of these more accurate photometric parameters? In the early age, when filament lamps had just been invented, the brightness of a 1-watt filament lamp is approximately equivalent to then light from one candle. Gradually, people related power consumption with brightness. Same situations happed in fluorescent lamps. Nowadays, LED lights have taken the place of traditional lights in many areas. It is improper to represent brightness though power consumption. As for LED Grow Lights, brightness of which is hard to be related with power consumption, can only be clearly represented by more scientific photometric parameters mentioned above.

 

As for light sources of LED lights, luminescence ability can be represented by the light distribution curve measured on their surface. Luminescence ability of the entire LED lights, the light distribution curve should be measured in front of projectors. If two lamps, no matter what type of lamps they are (super high power LED or traditional filament lamp), they will have same brightness if the light distribution curve measured before the entire lamp is similar. Brightness measured though illuminometers are usually different from brightness felt by our eyes. Under circumstances that accurate luminous flux is not necessary, brightness can be roughly represented by the measuring results from illuminometers. Since this method is cheap and easily to be realized.

Investment Opportunities of shop LED Lighting Should Be Judged Rationally

During current years, various aspects of China’s LED industry are packed with industry and non-industry investors and nearly 4000 enterprises found only in the shop LED lighting application side in the past two years. Flowers are flourishing before the spring really comes, which is quite appropriate to describe the status of this industry. On one hand, market participants become more and ambitious; on the other hand, the industry chain develops unevenly. What investment opportunities lie behind this glittering industry? PV industry and wind energy investment boomed a few years ago and now retreat. What lessons can be left to this wave of LED Lights market participants?

Semiconductor lighting is recognized as one of the most promising technology of the 21st century, opening the third revolution in  shop LED lighting of the human society, bringing huge economic benefits. Over the past decade, the average annual growth rate of the global LED downlight market’s scale is over 20%; the growth high brightness LED market is more rapid, the average annual growth rate 46% from 1995 to 2005. The size of the market in 2008 reached 5.1 billion U.S. dollars, accounting for the ratio of the LED market more than 80 percent growth from 40% in 2001, with a conservative estimate that in 2012 the market size is expected to reach $ 11.4 billion.

In this industry chain which is full of highlights and value, the upstream firm took more than 70% of the profits, which is a capital-intensive, high technology content, high rate of return link. The core patented technology of upstream is concentrated in Japan Nichia (Nichia), the United States Corey (Cree), Germany Osram (Osram), and a small number of overseas giants, belong to a typical oligopoly business (Schedule). In the fields of epitaxial wafers and chips, the U.S. and Japanese companies take a monopoly advantage.

Shop LED lighting growth in the mainland should follow the bottom-up path. To think about the early industrial mode, it may be worth LED domestic enterprises to seize market opportunities and grow their own strength.

The LED street lighting market in the turbulent perhaps is a new feast for Chinese manufacturing enterprises. PE should be rational in this area to avoid irrational thinking of the investment in solar energy industry market. On the basis of market-oriented principles to select the appropriate enterprises, it will be illuminate the manufacturer and PE future.

Filament lamps should not be replaced by super high power LED though power consumption judgment (1)

“What is the equivalent LED lamps for xx watt filament lamps?”. “We replaced an energy-saving lamp by a LED down light with much less power consumption, but coming out that it looks much dimmer than before. Should we use a super high power LED instead?” these are questions that would be asked by customers mostly. In fact, this comparison criteria is inaccurate. We cannot judge the brightness of a LED lamp and a filament lamp just tough their power consumption. Traditional lamps like filament lamps and fluorescent lamps, they usually send out a full space light due to their internal constructions. In practical applications, no matter LED lights or traditional filament lamps, all of them will be used together with other reflecting tools, like projectors or other lamp covers with reflecting function. Lamp cover plays a role of light re-distribution. This re-distribution will be different according to different lamp covers used. For instance, straight tubular fluorescent lamp can be mounted either by lamp covers with reflection function or by lamp covers without reflection function. However, the lighting effects are totally different for them, as well as effective luminous flux. Thus, it is improper to compare LED lights and filament lights just though power consumption. To what subject you are comparing? Filament tubes without any other auxiliary components? Filament tubes only mounted by ballasts? Or filament tubes with full set of reflecting components including projectors? This kind of view makes no sense without any premises.

 

Filament lamps should not be replaced by super high power LED though power consumption judgment

 

It is unreasonable to compare LED lights with traditional filament lamps just though power consumption. Traditional lighting sources have relatively stable technology, power consumption is basic a linear relations with luminous flux. Thus power consumption can present brightness to some degrees. While this linear relations cannot be established between LED lights’ power consumption and their luminous flux due to the unstable of the photosynthetic efficiency value of LEDs. Even for super high power LED, there is no such relation. With the rapid development of LED lighting technology, the improvement between the power consumption and the luminous flux will be continued. Thus it is impossible to give out a certain relations between them in near future. Maybe after several years, this problem can be solved. Then we can compare the brightness of LED lights and traditional lights by judging power consumptions.

 

 

Does high efficiency white LED look brighter than filament lamp in same luminous flux? (2)

In previous article, we mentioned about the concept that under different circumstances people feel different light brightness. Even these lights come from the same lamp. The most important reason is that radiations energy will change the brightness of this light in our eyes. For example, if the ground and walls are blue. In same luminous flux, high efficiency white LED looks much brighter than filament lamp. In the optical spectrum of white LED lights, the peak value of the light intensity distribution is between 466nm and 485nm (blue-ray). Thus most of the light coming from white LED lights will be reflected by the ground and walls. On the contrary, if the ground and walls are red colored, more light from filament lamps will be reflected. In such condition, we cannot simply conclude that high efficiency white LED looks brighter than filament lamp in same luminous flux. That is all depends on surroundings.

 

Does high efficiency white LED look brighter than filament lamp in same luminous flux?

 

So far, we have concluded two different results. One is from the measurement result of illuminometer and the other one is from our eyes’ feeling. Differences between them are caused by the unscientific measuring method. In the matter of fact, using illuminometers to measure luminous flux is not as accurate as we all considered. The light measured by illuminometers is light directly coming from light sources, and the light caught by our eyes is mostly from the ground. They are totally different objects. But why designers and engineers still use this method to measure the luminous flux? Firstly, this method is relatively easy compare to other methods. Secondly, it can provide a rough measuring result in most conditions. Finally, illuminometers are much cheaper. These three advantages make illuminometers frequently used in situations that accurate brightness data is not necessary. Many design houses for residential decorations use this method to reduce their cost.

 

In conditions that LED high bay light intensity results are required, methods measuring light intensity are more accurate. Engineers can measure the light intensity on the surface of the ground and walls directly. Values measured by this method will be much more closed to results perceived by human eyes. Brightness meter is an optical instrument typically used to measure light intensity. But this instrument is more expensive than illuminometer and Eneltec LED Flood Lights. In commercial field, brightness meter is not so popular as illuminometer.

Does high efficiency white LED look brighter than filament lamp in same luminous flux? (1)

Does high efficiency white LED look brighter than filament lamp in same luminous flux? This is a rather complex problem. It involves properties relate to human optic nerve system, and also some optical concepts. From the view of the optical measurement, as long as different testing LED lights have same luminous flux, they should look like the same in human eyes. No matter what color they are. However, if the testing object is light radiance, the result will be different. Tow bundle of lights with same radiation energy but different color temperature, will look different in human eyes. A lot of technician did not take these differences into account, leading to the inaccuracy of their testing results. In their opinion, high efficiency white LED street light has been proved much brighter than filament lamps in all conditions.

 

Does high efficiency white LED look brighter than filament lamp in same luminous flux?

 

If using luminous test to compare the brightness of high efficiency white LED and filament lamp, there is one point needs to be noticed: the object should within the same surroundings (consider the radiation energy from the ground reflection), otherwise, the result will be inaccurate.

 

When we design an indoor led lighting products application, the commonly used instrument for testing light intensity near the ground is illuminometer. However, even for the same lamp with same projectors and luminous flux, light intensity near the ground will be different due to different ground conditions. Similarly, we will recognize them as different light since they have different brightness. Illuminometer is a type of instrument typically used to measure light intensity though the optical energy caught by the sensors mounted on its head. When we measure the light near the ground, we are only measuring the lighting coming from light sources. What about other light reflected by the ground and walls? After absorbing and diffuse reflecting by the ground, some light energy converts into radiation energy. The amount of energy all depends on what material the ground and walls used and the construction of the entire room. In other words, light caught by illuminometer is just part of what we have “seen”. That is reason why when illuminometers gave out same measuring result, we feel different light brightness.