Challenges still existed in using LED

LED light bulbs will soon be adopted in household lighting and industrial lighting because of its characters of energy efficient and environmental protection. But challenges still existed in using LED. 

LEDsin different colors-Light Emitting Diode

LEDs are currently an initial capital cost compare with other conventional lighting technologies. For example, a single AC bulb replacing a 25 watt incandescent bulb, will cost about $40. We would have replaced all the conventional bulbs with LEDs if the initial capital cost reduced, isn’t it?

LED performance largely depends on correctly engineering the fixture to manage the heat generated by the LED, which causes deterioration of the LED chip itself. Over-driving the LED or not engineering the product to manage heat in high ambient temperatures may result in overheating of the LED package, eventually leading to device failure. Adequate heat-sinking is required to maintain long life. The most common design of a heat sink is a metal device with many fins, which conducts the heat away from the LED. 

Current LED technology has its limitations. LEDs utilize expensive sapphire-based technology in their construction. This is perhaps the largest contributing factor in high production costs.

LEDs that are poorly designed or poorly manufactured tend to flicker, dim, shift in color, draw power even when they are turned “off” or provide uneven lighting within a year of regular use. LEDs are rated to last for several years before they need servicing or replacing which is why consumers should be weary of LEDs that operate improperly within their first year of use.

LEDs are very small, typically less than .25-inch in diameter. Such small lights have their limitations, LEDs are often grouped together in clusters to broaden their applications. One single LED does not produce much visible light which is why they are offered in clusters for everyday home-use. Some clusters feature diffusers which helps disperse light from the LEDs more evenly.

To Light Up a Room, a Liquid-Filled Bulb

In the debate over the merits of incandescent light bulbs versus compact fluorescent lamps, LED bulbs have become a viable alternative. Switch Lighting is hoping to ride the wave of rising consumer interest with its own series of LED bulbs.

An LED Spot Bulb from myled.com

Switch assembled a team of engineers and physicists in its Silicon Valley headquarters in 2007, and produced a bulb last year with distinct design that has won several innovation awards.

The bulb incorporates technology that Switch calls a LQD cooling system, a patented design that bathes the LED with a coolant made of liquid silicone. The liquid diffuses the light over the surface of the bulb, producing light that is omnidirectional and illuminating a room similar to the way an incandescent does. The shape is similar, too, for those who prefer traditional A-series light bulbs.

The Switch bulbs turn on instantly, unlike fluorescent lighting, and are compatible with standard dimmers. Their durable design makes them much harder to break than incandescent or fluorescent bulbs.

But Switch bulbs are still relatively expensive, and they are hard to find. I had to do a little searching on the Web and found the Switch60 bulb at Batteries Plus for $50.

Make the investment now, Switch says, and you will be rewarded with lower electric bills for years to come. According to Switch, the bulbs have a lifespan of 25,000 hours, 25 times longer than an incandescent. They come in wattage equivalents of their incandescent counterparts; for instance, the Switch60 bulb emits 800 lumens, about the same as a 60-watt incandescent bulb.

Switch says its bulbs can be used in any fixture, even enclosed, recessed or outdoors. However, I live in a tiny apartment in New York, and have none of those options. So I replaced the CFL bulb in a table lamp in my living room with a Switch bulb.

The light was warm, reminiscent of the incandescent bulbs I used to use, and not as white as the light from the CFL. This is a personal preference, but visitors noticed the difference in the quality of the light almost immediately, remarking that they had lost their ghostly pallor. Switch bulbs probably won’t appeal to everyone, but those who value good design from a premium product will appreciate them.

                                                                    This article is reprinted from GREGORY SCHMIDT

The First Country Banned Incandescent Lamp - Australia

According to a 2006 International Energy Agency report, lighting absorbs nearly one-fifth of global electricity generation, more than is produced by hydro or nuclear stations and about the same amount produced from natural gas. From Australia to Russia, energy-efficient light bulbs are gaining political traction around the globe. Governments are promoting energy-efficient light bulbs like LED in place of incandescent lamp across the world.

Australia is the first country to launch a plan for banning incandescent bulbs. Australians are among the world’s largest greenhouse gas emitters per capita, and the country has refused to sign the Kyoto Protocol. The new law reduced Australia’s current emissions by 800,000 tons by 2012 and simultaneously cut household lighting costs 66 percent.

More and more Lawmakers from other country hope to follow Australia’s lead. They are the United Kingdom, Canada, California, the New Jersey. Ontario premier Dalton McGuinty estimates that a ban of the energy-sucking incandescent would save enough energy to shut down one coal-fired power plant, according to the Toronto Globe and Mail.

The European Lamp Companies Federation, with includes General Electric, Siemens, and Royal Philips Electronics, said it plans to promote “public incentives to encourage consumers to purchase more efficient products and set performance standards that will eliminate the least efficient products from the market.”

European bulb makers announced that they would work together to promote energy-efficient lighting to European consumers, including light emitting diodes, or LEDs, which can save even more energy than CFLs.

Even Russia, a country with huge oil and gas reserves, is beginning to join the plan of banning incandescent lamp. As Moscow resident Nastya Meshkova observed, “It’s important to save energy, and if it’s going to save my energy bill of course I'll do it.” The IEA reports that a global switch to efficient lighting systems would cut the world’s electricity bill by nearly one-tenth.

Several Types of LEDs

Light emitting diodes, or LEDs, are electronic lights. They are produced in a variety of shapes and sizes. There are several types of LED lights, which can be found in any number of electronic devices and have various functions.

The first is Miniature LEDs. They are some of the most common types of LED lights and can be found in small electronic devices. Miniature LEDs are used in an array of devices with surface-mount or through-hole designs and mostly used as indicator lights on devices such as calculators or cell phones.

 It is possible to use a miniature LED light without package, such as a cube or dome. Lights not packaged are simple semiconductor chips connected to conductive wires. Miniature LED lights are divided into three categories: ultra-high output, standard and low current.

The second is High-Power LEDs(HPLEDs). They are produced a much stronger light source than most other LEDs and becoming more popular for house decorating and lighting.Their initial cost is relatively high but due to a long lifespan, they typically save on energy costs in the long term. So they are good replacements for fluorescent and incandescent lights as they are proving to be more energy saving. HPLEDs are known as solid state lights. Their electroluminescence is generated through a small, solid mass, rather than through more sensitive and brittle bulbs or fluorescent tubes. The danger of an HPLED overheating is high and must, therefore, be mounted on heat-absorbent material, allowing the light to cool through convection. Too much heat can cause an HPLED to burn out quickly.

The third is Super Flux LEDs. They can be found most commonly in large panels like billboard advertising. Large video screens are often made from LEDs. Large Panels types of LEDs are designed for maximum light emission, as they consist of two positive and two negative leads.

The forth is Flashing LEDs. They are stand-alone lights that serve as indicators. To make a LED flash or blink, a vibrator is integrated into the circuit that interrupts its flow in intervals.

The fifth is Bi-color LEDs. It combines two light emitting dies connected to one lead in one encasing, allowing for the case to emit two different colors. The current flow of the dies alternates to produce the color variation. Bi-color LEDs can also produce a third light when the flow of both dies is equal.

The last is RGB and Tri-color LEDs. RGB LEDs are the red, green and blue light emitting diodes, commonly found in LED televisions and projections. The LEDs are emitted through a four-wire connection on a common lead.  Tri-color LEDs combines two light emitting dies in one encasing. In contrast to the bi-color LEDs, the tri-color dies are connected to two leads. This enables the two LEDs to light up simultaneously and be controlled. The third lead shares one of the common leads.