LED - Technical Notes

Lighting represents almost 20% of global electricity consumption. With the emerging concept of retrofitting, it is desirable to spare as many kilowatts of power as possible. This not only results in better utilization of energy inside buildings but also helps us to cut our electricity bill.  It is quite feasible and economically viable by just making few changes inside our buildings or homes, for instance, changing paint color of the walls, choosing windows that prevent unnecessary heat transfer and even the simplest trick is to use LED light bulbs of suitable illuminance and wattage instead of traditional light bulbs. Light Emitting Diodes (LEDs) are extremely energy-efficient. Nowadays LEDs are used for household light  fixtures due to following reasons: 1)  Cost-Saving &  Energy Efficiency  The number one benefit of LEDs is their energy efficiency.  In comparison to incandescent, halogen or fluorescent (CFL) lamps with LED lighting, we can expect e...

LEDs are sustainable, eco-friendly, efficient, and safe lighting solutions that deliver multiple benefits to the users.   One of the benefits of LED is its long lifetime. Because they have no movable parts  or filaments tht may break, LED’s can have long lifetime. LEDs generally do not fail by burning out but will slowly reduce in light output over time; as solid state devices they will continue to operate even after 100,000 hours, continuing to use electrical power even if they produce very little useful light. LEDs, however, follow a different method for measuring life expectancy called lumen maintenance. What is lumen maintenance? Lumen maintenance is an approach of measuring the light output (lumens) of a brand new light source and comparing that with its light output after a certain period of time. L70 and L50 are examples of lumen maintenance – benchmarks for when 70% or 50% of a lamp or fixture's total light output remains. What is L70? It is rated lumen-maint...

In LED lights ‘Color’ refers to the color of light that the diode emits – this can be any color.   Colored LEDs are all around us, in decorative applications, also being used for communication and indication purposes.  LEDs can generate up to 16 million colors. The material used in the semiconducting element of LED determines its color. A color-changing LED contains three separate diodes within the same bulb casing. Each of these diodes emits its own, specific color – red, green, or blue. When all three diodes are switched on at full capacity, white light is produced. Adjusting the intensity of each diode allows a range of different colors and shades to be created. RGB Concept The RBG concept is an additive model, these colors are used because our eyes see all colors as different combinations of red, green, and blue wavelengths. Red and amber LEDs use the aluminum indium gallium phosphide (AlInGaP) material system. Green diodes, whereas, use gallium phosphide and blue...

A DOB "driver-on-board" LED light is an LED lighting system (either an LED bulb or an LED luminaire) that incorporates a light engine (driver-integrated LED assembly intended to operate directly on line voltage power) with an integrated on-board driver.  In conventional LED lighting systems the driver is typically separated from the LED assembly and fabricated on an FR4 printed circuit board (PCB). This configuration is based on the consideration that LED drivers have been dominantly designed as switching mode power supplies. SMPS drivers typically make use of bulky, expensive and unreliable reactive components such as inductors and capacitors. The use of reactive components necessitates a dedicated FR4 board which provide adequate routing layers for component interconnects. In an integrated lighting system, the considerable volume of a typical SMPS driver creates a need for an adequate space within the lighting system in order to accomm...