Misunderstanding in choosing LED Lighting Products
Misunderstanding 1, too high expectations of the service life.
LED lighting manufacturers predict LED light life up to 100,000 hours MTBF (mean time between failures, conventional lamp manufacturers to measure source life standard). However, like all basic light sources, LED light lumen depreciation over time and attenuation. Therefore, although the LED lights lighting time can be very long, MTBF is not the only consideration in determining useful life. LED lights lumen depreciation is affected by numerous environmental conditions such as ambient temperature, humidity and ventilation. Lumen depreciation is also under control, thermal management, current levels, and many other electrical design considerations (the above-cited U.S. CK company description).
Many sales in the marketing of LED lights provide customers with some vague information, misleading, such as LED light life of 100,000 hours, 100,000 hours here is intended by the manufacturer to use LED lights life. As a lighting source, lamp brightness has a gradual decay process of darkening (such as fluorescent lamps, energy saving lamps), the process referred to bad light. LED lights at the application level, the light fades more than 50%, the human eye can clearly feel the change in brightness, brightness products at this time we believe does not apply to lighting. Many producers and engineering companies in the use of low-cost three to six months or so LED lights, LED lights brightness often found significantly less bright when just installed, and even almost non-existent, it is not taken into account because of bad light LED lights causes. In summary, we have to pay attention when you buy LED lighting is its light decay rate, rather than the use of time.
Misunderstanding 2, misunderstand the actual light angle as effective angle.
LED lights emitting angle perspective into effective and practical light angle. Luminous intensity is half the value of the direction of the axial strength of the light emitting axis (normal) angle of the effective angle. Half-value angle 2 times the angle (or called half-power angle) is the actual light angle. In the other half of the angle of axial strength because the light is too weak in practice not included in the effective angle. (The following figure shows a side view of piranha particles, solid and broken lines are not included angle between the effective angle)
So we should be concerned about when purchasing products emitting angle of the actual product, Computational Engineering Products Used in quantities subject to actual light angle, the effective light angle can be used as reference values.
Misunderstanding 3, the higher produce higher brightness.
The brightness LED lights to measure the luminous intensity, luminous intensity fingering line (pair of cylindrical light emission tube is its axial) direction of the luminous intensity per unit solid angle of the luminous flux emitted by the unit is candela (Candela, cd) . Due to the general LED lighting luminous intensity, luminous intensity so common milli candela (mcd) for the unit. Typically, the light source to the different intensities in different directions to the luminous flux emitted in a particular direction per unit solid angle of the visible radiation intensity emitted light intensity that is called, referred axial brightness.
From the force at the same time acting for many incoming electrical power concept, the current acting fast, the electric power is large; current acting slow, the electric power is small, or that the at equal period, the current work done, the more electric power, the greater, In the LED lights, not the greater the power, the higher the product brightness. In the three lights Electronics red LED lights, for example, the axial brightness 1200mcd, the current is 40ma, power is 0.48W; three lights at the same brightness white LED lights, the current is 18ma, power is only 0.24W; can seen two kinds of optical power at the same brightness are different. So when we buy LED lights concern is its axial brightness, rather than power.
Misunderstanding 4, choosing of white LED lighting modules.
High brightness (blue-green) white LED lights are sensitive to static electricity, which is determined by characteristics of the decision itself, LED lights. It can allow more than the maximum forward DC current and the maximum reverse voltage may cause damage or breakdown LED lights. If three lights LED lighting modules, each lamp will have an Antistatic resistance, coupled with current limiting resistor is used, a total of four. Antistatic resistance can effectively inhibit electrostatic damage to the LED lights; limiting resistor primarily serves to limit the amount of current through the entire module, this design can effectively improve the anti-overload LED lights, and enhance product stability. Meanwhile, four resistors marking is complete Identity Module is simply a sign of quality is stable or not.