CFL vs. LEDBy -

Case study - physics

Mansvini Misra, X-B

INDEX❶ CFL – Compact Fluorescent Lamp

❷ More about CFL

❸ LED – Light Emitting Diode

❹ More about LED

❺ CFL vs. LED – Which Bulb is the Best? : ❶ Advantages

❷ Disadvantages

CFL - Compact Fluorescent LampA compact fluorescent lamp (CFL), also called compact fluorescent light, energy-saving light, and compact fluorescent tube, is a fluorescent lamp designed to replace an incandescent andescent lamps. The lamps use a tube which is curved or folded to fit into the space of an incandescent bulb, and a compact electronic ballast in the base of the lamp.Compared to general-service incandescent lamps giving the same amount of visible light, CFLs use one-fifth to one-third the electric power, and last eight to fifteen times longer. A CFL has a higher purchase price than an incandescent lamp, but can save over five times its purchase price in electricity costs over the lamp's lifetime. Like all fluorescent lamps, CFLs contain toxic mercury which complicates their disposal.

More about CFLIn many countries, governments have established recycling schemes for CFLs and glass generally.The principle of operation in a CFL bulb remains the same as in other fluorescent lighting: electrons that are bound to mercury atoms are excited to states where they will radiate ultraviolet light as they return to a lower energy level; this emitted ultraviolet light is converted into visible light as it strikes the fluorescent coating on the bulb (as well as into heat when absorbed by other materials such as glass).CFLs radiate a spectral power distribution that is different from that of incandescent lamps. Improved phosphor formulations have improved the perceived color of the light emitted by CFLs, such that some sources rate the best "soft white" CFLs as subjectively similar in color to standard incandescent lamps.

LED – Light Emitting Diode

A light-emitting diode (LED) is a two-lead semiconductor light source. It is a basic pn-junction diode, which emits light when activated. When a fitting voltage is applied to the leads, electrons are able to recombine with electron holes within the device, releasing energy in the form of photons. This effect is called electroluminescence, and the color of the light (corresponding to the energy of the photon) is determined by the energy band gap of the semiconductor.An LED is often small in area (less than 1 mm2) and integrated optical components may be used to shape its radiation pattern.Appearing as practical electronic components in 1962, the earliest LEDs emitted low-intensity infrared light. Infrared LEDs are still frequently used as transmitting elements in remote-control circuits, such as those in remote controls for a wide variety of consumer electronics. The first visible-light LEDs were also of low intensity, and limited to red. Modern LEDs are available across the visible, ultraviolet, and infrared wavelengths, with very high brightness.

More about LEDEarly LEDs were often used as indicator lamps for electronic devices, replacing small incandescent bulbs. They were soon packaged into numeric readouts in the form of seven-segment displays, and were commonly seen in digital clocks.Recent developments in LEDs permit them to be used in environmental and task lighting. LEDs have many advantages over incandescent light sources including lower energy consumption, longer lifetime, improved physical robustness, smaller size, and faster switching. Light-emitting diodes are now used in applications as diverse as aviation lighting, automotive headlamps, advertising, general lighting, traffic signals, and camera flashes. However, LEDs powerful enough for room lighting are still relatively expensive, and require more precise current and heat management than compact fluorescent lamp sources of comparable output.LEDs have allowed new text, video displays, and sensors to be developed, while their high switching rates are also useful in advanced communications technology.

CFL vs. LED – Which Bulb is Best?ADVANTAGES

CFL AdvantagesCFL, or compact fluorescent, is simply a mini version of a standard fluorescent light bulb, However, these bulbs fit in standard light sockets without any adaptor. The light appears much like the incandescent light we’re used to, and looks nothing like the harsh lighting we associate with offices or school buildings.

LED AdvantagesLED lights last longer, so even though you’re paying more at purchase, you buy fewer bulbs over time. These bulbs fit in standard light fixtures with no adaptor necessary. LED makes very nice lighting for effect and decorative purposes.

Disadvantages

CFL DisadvantagesThe primary disadvantage to CFL lights is the mercury contained in the bulb. This is ordinarily not a problem, but if the bulb breaks clean up is a hassle. Mercury is a dangerous heavy metal, and proper cleanup and disposal of CFL bulbs is critical. Never put a used CFL bulb in with the rest of your trash. Contact your local waste management company to learn how to properly dispose of used CFL bulbs.

LED DisadvantagesLED lights generally cost more to buy than CFLs, but manufacturing technologies are lowering these prices continually. These lights are directional, meaning they are excellent for lights under cabinetry, but not as suitable to table lamps. Some of the newer LED lights come with diffusers, which helps some.

Special Thanks and Support To :-

❶ www.google.com

❷ www.forbes.com

❸ www.wikipedia.com

❹ research work by phillips (electronical company)