标签：LED power suppliers

More than 80% failure of LED products is from LED power suppliers

LED lighting market is fast growing, along with the rapid development of LED lighting industry. On one side, manufacturers for traditional light power supplies aggressively introduced new LED power suppliers or upgraded products for LED lights. On the other side, man entrepreneurial companies have been founded as well. However, the power technology is not mature yet. There is still no unified standard and the corresponding market is also in chaos. Relevant experts believe that LED lighting market will be finally dominated by a few giants. Marketing strategy an product quality is the key to the final victory.

 

More than 80% failure of LED products is from LED power suppliers

 

2012 is a mixed story for LED lighting industry. Market is growing fast. But not every participants earned money at last. Most of LED street light suppliers did not make any profits. Most of LED tunnel suppliers only earned enough money to cover all charges. Some LED commercial lighting application providers with strong trade ability actually made money. All LED chip makers and packaging factories, both domestic and overseas earned money in 2012.

 

It is noticed that most manufacturers for LED power suppliers also had a good harvest in 2012. LED power suppliers are technically belong to the traditional electronics industry. Chinese manufacturers have strong manufacturing capabilities in this area. Although it is an emerging industry, price war has started in advance, especially in low-powered LED driver field. In fact, the price of small-powered LED drivers is very transparent, normally 24-25 yuan.

 

But LED drivers are still a highly profitable business. The relatively high technical threshold and large capital investment are major reasons. In addition, High-powered LED drivers are usually used in high-powered LED lighting applications, such like LED street lights, LED tunnel lights. These lamps are mainly used in government lighting projects and supported by government policies. Manufacturers will use best components and modules on their products to obtain a good effect, which will virtually increase the production cost at last.

 

According to incomplete statistics, about 80% failure of LED lighting products comes from LED power supplies. In recent years, with the continuous improvement of packaging technology and cooling technology, the stability of LED drivers has reached a satisfied level. The additional light attenuation and color shift all comes from the unreasonable cooling design.

How to make competent LED power suppliers for high-power LED lighting products

Intelligent control is one of advantages of LED lighting technology. LED power suppliers is a key point of LED intelligent control. Intelligent control have achieved obvious results in LED street lighting and LED tunnel lighting. Central controllers can switch on/off lamps or let them maintain in a certain energy consumption level depending on the density of vehicles on roads or in tunnels. These functions can be realized through all kinds of sensors and embedded systems. Intelligent control in one hand can make LED lighting technology more energy-saving and on the other hand can guarantee the safety of drivers by providing suitable light for drivers within tunnels. Research data demonstrated that tunnels using intelligent LED lighting system can reduce the accident rate by 2%.

 How to make competent LED power suppliers for high-power LED lighting products

Give up high power or supper power, replaced by more stable small-power suppliers. High-power LED circuits will generate more power. High working temperatures are a chief culprit of LED power suppliers’ failure. Relatively, small-power suppliers have been fully developed. They have more advantages in stability and production cost. As a matter of fact, most high-power designs have not been fully tested and verified. In another word, they are still in an immature state before getting to the market. Failures occurred frequently.

 

Cooling and protection is the main external factor for LED power suppliers’ failures. Not only that power suppliers themselves generate heat, lamps body can create heat also. How to conduct this heat into the air was always a big challenge for LED lamp designers. Within such limited space, it is very easy for heat to gather and form “heat island” effect. This will cause huge damages to power suppliers. Isolated circuit is a good solution for this problem.

 

The possibility of maintenance. Power failure is inevitable. The only way is simplifying the structures, making power replacement as easy as lamp body replacement.

 

Protection. Protection is another important aspect for LED lights. The penetration of moisture may cause short circuits. Dust on shells also affects the cooling effect of power suppliers. Exposure to sunlight results high temperature and aging circuits and electronic components. Experiments results show that rotating wiring plug has a higher failure rate, normally caused by moisture penetration.


Notice points for LED power suppliers

With the improvement of LED packaging and LED cooling technology in recent years, the stability of LED lighting products has reached up and maintained in a high level. An unreasonable cooling section design may cause inevitable lighting attenuation and light shift. Relatively, problems caused by unreasonable drives design are much more serious: such like failure and flickers. Nowadays, LED power suppliers have been the weakness of the entire LED lamps. In another word, according to bucket analogy, the service life of LED power suppliers has become the service life of LED lamps.

With the improvement of LED packaging and LED cooling technology in recent years, the stability of LED lighting products has reached up and maintained in a high level.

Normally, light heads of Street Light are separated from power suppliers. In most cases, it was light heads that failed to work firstly, like Pressure Sodium Lamps. The service life of Pressure Sodium Lamps is around one year.

 

Solving problems of LED power suppliers is rather important, since most LED lamps’ failures are mainly caused by them. Due to lacking of a uniform standard, power suppliers on the market are various in circuit designs, dimensions and other electronic parameters. It is very difficult to replace them once failed. With the emergence of high-power LED lamps, such like high-power LED High Bay Lights, high-power LED Tunnel Lights and high-power LED Flood Lights. Among which LED power suppliers hardly sustained for a long term. Additionally, most of the power suppliers are designed as embedded previously. Maintenance works was beset with difficulties. During a very long period of time, customers had no willing to buy any high-power LED lighting products. “They can be easily damaged. We buy high-power LED lamps since we are looking for a more advanced lighting technology which can help us save more energy, save more money. On contrary, these high-power LED lamps cost us even more.” Complained one of buyers.

 

However, how to make LED drives more reliable? Here we conclude several points:

 

  1. Get rid of multi-output design concepts, develop single output circuits (duplex output tops). Give up high current or supper current, replaced by small current. Multi-output drives will increase the complexity of circuits. Currents on different branches will interfere with each other. Solving this problem will cost manufacturers a large amount of money. Meanwhile, it is current that generate heat (heat is proportional to the square of current). In other words, if current increased to 2 times of original values, the entire system will generate 4 times heat than before. Thus, single output/duplex output will dramatically reduce the failure of LED power suppliers.

How to choose suitable LED power suppliers?

The load characteristics of LED determine that only power suppliers with higher reliability can be used. Within a certain section, increasing the external voltage will cause an exponentially increased current. When LED Lights work in the normal condition, subtle changes in voltage will cause widely vibrations in current. Thus most switching power suppliers are no longer suitable for LED applications. Because the output of switching power suppliers is not a constant value. However, how to choose right LED power suppliers for LED applications?

The load characteristics of LED determine that only power suppliers with higher reliability can be used.

LED is very sensitive for input voltage. The normal working voltage for LEDs is around 3.0V-3.6V (different power has different input voltage). A slightly fluctuation in input voltage will lead to a violent change in current, consequently causing a violent power output. If the vibration exceeds a certain threshold, accidents may happen. Experiments proved that adding voltage suppressing components (TVR, TVS) in circuits is useless.

 

Reliability and efficiency are constrained by each other. Power suppliers with higher efficiency must have a lower reliability, vice versa. In order to reduce the influence of output voltage to input voltage, electrical energy must go though several transformations. For example, the reliability of BUCK circuit is not very high. But BUCK-BOOST circuit has much better reliability than BUCK circuit. This has been proved. Known by those who had electricity background, when the switch of BUCK circuit is turned on, LED HIGH BAY loads and inductances are cascaded in the circuit under 300V external voltage. BUCK-BOOST circuit separately charge inductances firstly. When the BUCK-BOOST circuit is switched off, then inductances in BUCK circuit will transmit electrical energy to LEDs. The difference between them is BUCK circuit will work directly under 300V voltage in a period of time while LEDs in BUCK-BOOST circuit will not be explored under such high voltage. Thus the later has a much better reliability than the former. And relatively, BUCK-BOOST circuit actually has two electrical transmission sections: from power supplier to inductances and then from inductances to LEDs while BUCK circuit need only one step to charge LED STREET LIGHTS. In the aspect of efficiency, BUCK circuit has a better performance.

 

Thus currently used LED power suppliers are followed such law: isolated circuit has a better reliability than non-isolated circuit. Low voltage circuit has a better reliability than high voltage circuit.