LED - Technical Notes

The latest LED improvement has been “Chip On Board” or COB innovation.  A COB (Chip-on-Board) is an LED packaging technology that describes mounting multiple LED chips directly onto a substrate to form a single module.    Multiple LEDs, minuscule in size, are wired and packaged together into a single ceramic or copper board so that they function as a sole light source. ​ They are sometimes nicknamed “fried eggs” (when they are not lit) because of their yellow phosphor circle on a white board. COBs are made up of multiple chips, usually with a minimum of 9 on a board.  Due to the small size of the LED chips (imagine a quarter), Chip-on-Board technology allows for a much higher packing density than surface mount technology (SMD). COB chips only have 1 circuit and 2 contacts, regardless of the number of the diodes. When a COB LED package is energized, it appears more like a lighting panel than multiple individual lights as usually the case with other LED packages, li...

LED downlights are recessed systems those are designed and engineered for optimal operation of an LED module and also efficient regulation and precise distribution of its luminous flux. In conjunction with custom designed secondary optics, an array of discrete LEDs can be designed to provide uniform ambient illumination; a single-point LED can create a spot beam with the highest punch possible for accent lighting. The integrated design allows the LEDs to make full use of the luminaire housing for heat sinking, thereby keeping the LED junction temperature under control and maximizing the performance potential of LEDs. In systems with co-located drivers, miniaturized LEDs or compact LED arrays make space for an electrical compartment that can accommodate full-featured driver and control circuitry while isolating thermal stresses from the LED module. An integrated LED downlight generally consists of housing, an LED light module, a driver, and a trim. Housing The housing is the...

LED panel lights offer a contemporary, sleek alternative for ceiling lighting to old-dated fluorescent lighting. An LED panel light is designed to  provide sufficient lighting of varied light intensity, or lux level. Panel lights offer “edge to edge” lighting for smooth, even and bright output. LEDs are oriented directly toward light diffusing layer, inducing the light emitted from LEDs to shine directly onto light diffusing layer. Two of the primary lighting panel structures are direct-lit backlight modules and edge-lit modules The difference between edge-lit and back-lit lies in the position of LEDs and the usage of LGP(light guide plate). Normally, Back-lit Panel Light doesn’t have any LPG due to direct shining method. A direct-lit LED panel comprises a number of LED light sources which are directly disposed under a panel. But LED is a form of directional light source, of which light output intensity is strongest at 90 degrees. LEDs are oriented directly toward light dif...

A LED driver is an electrical device that regulates power to a LED or a string of LEDs. A LED driver is a self-contained power supply which regulates the power required for the LED or array of LEDs. The power level required changes throughout the LED’s temperature increases and decreases. Without the correct LED light driver the LEDs would become too hot and unstable resulting in failure and bad performance. To ensure the LEDs function perfectly, the self-contained LED driver is required to supply a maintained constant amount of power to the LED. It is a crucial piece to an LED circuit and to operate without one will result in system failure. Characteristics of an LED LEDs are semiconductors where the junctions produce light when powered by a DC voltage. Like all semiconductors, they only conduct electricity in one direction and, consequently, the connecting wires indicate the polarity. Light comes from the LED when electrical current flows through it from the anode (+) to the cathod...

The traditional method of diffusing light is to position a frosted glass in front of the light source. But glass has a very high absorption-coefficient, which blocks a large amount of the LED light output. Apart from that, glass is heavy, increasing the weight of the whole product. It also does not possess the required toughness and is prone to breakage. Nowadays, manufacturers are adopting new ways to develop cost-effective diffusers entirely from plastic. LED diffusers generally come with two types of surface finishes—opal (milky) and frosted (translucent). The distribution of light through frosted diffusers is good but the LED light is quite visible. Opal diffusers give better results than frosted options—the light is more uniformly distributed and the LED is well concealed. LED diffusers are available in a variety of forms like UV-tolerant films and rigid sheets. Also, they are manufactured using various high quality plastic materials. Polycarbonate (PC):   This is a ther...