Don't get carried away by the numerous advantages that LED lighting provides. Although this technology is unquestionably a significant development in the history of electric lighting, it also presents unique challenges. The lighting business is currently dealing with a crisis of a size it has never faced before. Engineering and design philosophies were transformed by solid state lighting. Lighting controls are now power electronics rather than simple illuminants. In other words, lighting system design is quite intricate. LEDs are semiconductor light sources that self-heat, are current-sensitive, and produce a lot of light. This raises the biggest issue with LED lighting since a multifaceted piece of work is crucial to the system's performance and dependability. The system engineering and comprehensive design of an LED lighting system also include other elements in addition to the LED package metrics. Thermal management, drive current regulation, and optical control are just a few of the additional interconnected variables at play.
Experts from a distance frequently develop a lengthy list of drawbacks for LED lighting. They would also never fail to highlight the dangers of blue light from LED lighting in order to make the tale interesting. In essence, white light is a synthesis of wavelengths from several colour bands. Regardless of the light sources from which the light is generated, all whites with the same colour look contain nearly the same amount of blue wavelengths in the visible spectrum. A correlated colour temperature (CCT) can be used to describe the hue of white light. A light source's CCT often relates to how blue it is. The percentage of blue wavelengths increases with CCT. Blue radiation from a 3000 K LED product is as low as that from a 3000 K incandescent lamp under the same luminance and illuminance circumstances, while blue radiation from a 6000 K LED product is as high as that from a 6000 K fluorescent lamp. The blue light danger is rarely an issue with white LEDs, as it is with other light sources. The engineering of white light's spectrum makeup is a major benefit of LED technology. Any spectral combination of light that benefits human health and wellbeing may be generated with LED lighting. In order to modify the quantity of blue radiation for a healthy spectrum of white light, human centric lighting, a significant technological trend that is fueling the expansion of the lighting industry, exploits the CCT tuning capacity of LED systems.
In actuality, LED lighting only has a small number of inherent drawbacks.
LED lighting's most well-known flaw is that it generates heat as a consequence. Because they produce heat inside the device packaging rather than radiating heat in the form of infrared radiation, LEDs are known as sell-heating gadgets. An LED converts around half of the electrical energy it receives into heat, which needs to be physically transported through a thermal channel. The kinetics of failure mechanisms including atomic defect production and development in the active area of the diode, carbonization and yellowing of the encapsulant, and staining of the plastic package housing may be accelerated if the device junction temperature is not kept below a certain limit. For every 10 ° C increase in junction temperature above the maximum rated junction temperature, an LED's service life will be reduced by 30% to 50%.
The fact that LEDs are fragile power electronics is both the most underappreciated and the worst limitation of LED lighting. They have very particular eating preferences; drive current. The high forward current sensitivity of LEDs has pros and cons. It improves the controllability of lighting systems but also makes it extremely difficult to regulate driving current. The driving current might fluctuate by a very little amount, which can affect the light output. LEDs are DC-driven devices, yet they frequently need to be powered by an AC source. The current output from the driver to the LEDs may still have a residual ripple (residual periodic fluctuation) if the alternating waveform is not completely suppressed after rectification. Due to this ripple, the LEDs blink at a frequency that is 100Hz or 120Hz, which is twice as fast as the incoming line voltage. The interconnection of LEDs' electrical and thermal systems complicates load regulation further. The amount of electricity provided to the LED reduces as junction temperature increases, forward voltage drops, etc. On the other hand, the amount of waste heat produced at the semiconductor die increases in proportion to the driving current. Overdriving an LED above its rated capacity might result in thermal runaway and early breakdown of the LED. Electrical overstresses (EOS) are the danger that poses the most risk to LEDs, though. When the component's maximum rated values are exceeded by the driving current or voltage, an EOS occurs. Electrical overstresses can have a variety of probable causes, such as electrostatic discharge (ESD), inrush current, or other transient power surges. Due of LEDs' susceptibility to various electrical stressors, strict management of the driving current is required.
The fact that LEDs have a high flux density is a third drawback. Glare may be produced by the intense light sources of directed light. High luminances in the field of vision might impair vision (disability glare) or make you feel irritated or uncomfortable (discomfort glare). The design of the luminaire can include additional optics to reduce glare, although doing so frequently leads to substantial optical loss.
Last but not least, as compared to traditional lighting goods, more system complexity results in higher initial costs for LED products. Because of this, cost optimisation is crucial to the process of designing luminaires. A series of issues will surface when the cost pressure overcomes the goods' dependability and performance.
