What are LED Light Bulbs

LED light bulbs give off directional light, so the light goes where you aim it. LED bulbs are closer to the colour of daylight — which new studies suggest is good for staying alert.

LED light bulbs can replace standard fluorescent or halogen light bulbs (led lights).The bright, white LED light produced by LED Light Bulbs works especially well for task lighting and reading light.

LED’s not only produce light more efficiently, they also have a tiny mirror that reflects light in one direction. A more directed light means less wasted light which can be ideal for caravans, led torches & backlighting.

Lifespan:

Bright LED signs ! Super bright 8mm wide-angled LED’s giving excellent daytime visibility, tested with up to 100,000 hours lifespan and controlled with the very latest advanced microchip power management.

Power Saving:

1. A normal light bulb wastes up to 80% of its energy through heat, a 40watt light bulb could be replaced with an equivalent light producing 4 watt led bulb, power saving.

2. The power saving is 1/10 that of a traditional bulb3. Brightness is 2-3 times brighter than the traditional bulb4. By 2027, LED lighting could cut annual energy use by the equivalent of 500 million barrels of oil, with the attendant reduction in emissions of carbon dioxide, the gas believed to be responsible for global warming.

How to Buy Dimmable LED Bulbs

Light-Emitting Diode (LED) bulbs are a relatively new technology in the lighting industry. They are considered a green technology, and require much less energy than traditional types of bulbs. One of the main criticisms of these bulbs to this point has been their poor compatibility with dimmer switches. While virtually any LED bulb can be used in most dimmable fixtures, the basic technology behind these bulbs leads to poor control over light levels. Fortunately, the newest LED bulbs are completely dimmable, and offer much more versatility than older models.

Instructions

Understand the limitations of LED bulbs. The traditional LED light bulb is not designed for dimming. When placed in a dimmable fixture, the bulb will have some dimming capabilities, which will generally perform best in the upper and lower 10 percent of light levels. If you want to enjoy the benefits of an LED, and only require a limited dimming range (for example, the light is either at full or near full brightness, or it is at minimum brightness, with no options in between), then any LED bulb will work.

Choose the correct LED bulb base type. For example, the traditional incandescent light bulb used in most home applications has a standard size base known as a "Type A base." Bulbs used in ceiling fans, lamps, or flood lights may have bases of many different sizes and shapes. When making your purchase, be sure to specify the appropriate base design. For more information on this topic, review the Lumi Select website found in the Resources section.

Compare brightness levels carefully. Many homeowners are accustomed to buying bulbs based on wattages. Because of the difference in light output between LEDs and other types of bulbs, LED bulbs should be purchased based on their light output, measured in lumens. This is an important consideration when purchasing these bulbs, as a 3 watt LED bulb can produce the same light levels as a 35 watt incandescent.

How Light Emitting Diodes Work ?

Light emitting diodes, commonly called LEDs, are real unsung heroes in the electronics world. They do dozens of different jobs and are found in all kinds of devices. Among other things, they form the numbers on digital clocks, transmit information from remote controls, light up watches and tell you when your appliances are turned on. Collected together, they can form images on a jumbo television screen or illuminate a traffic light.
Basically, LEDs are just tiny light bulbs that fit easily into an electrical circuit. But unlike ordinary incandescent bulbs, they don't have a filament that will burn out, and they don't get especially hot. They are illuminated solely by the movement of electrons in a semiconductor material, and they last just as long as a standard transistor.

What is a Diode?

Diode is the simplest sort of semiconductor device. Broadly speaking, a semiconductor is a material with a varying ability to conduct electrical current. Most semiconductors are made of a poor conductor that has had impurities (atoms of another material) added to it. The process of adding impurities is called doping.

In the case of LEDs, the conductor material is typically aluminum-gallium-arsenide (AlGaAs). In pure aluminum-gallium-arsenide, all of the atoms bond perfectly to their neighbors, leaving no free electrons (negatively-charged particles) to conduct electric current. In doped material, additional atoms change the balance, either adding free electrons or creating holes where electrons can go. Either of these additions make the material more conductive.

A semiconductor with extra electrons is called N-type material, since it has extra negatively-charged particles. In N-type material, free electrons move from a negatively-charged area to a positively charged area.
A semiconductor with extra holes is called P-type material, since it effectively has extra positively-charged particles. Electrons can jump from hole to hole, moving from a negatively-charged area to a positively-charged area. As a result, the holes themselves appear to move from a positively-charged area to a negatively-charged area.

A diode comprises a section of N-type material bonded to a section of P-type material, with electrodes on each end. This arrangement conducts electricity in only one direction. When no voltage is applied to the diode, electrons from the N-type material fill holes from the P-type material along the junction between the layers, forming a depletion zone. In a depletion zone, the semiconductor material is returned to its original insulating state -- all of the holes are filled, so there are no free electrons or empty spaces for electrons, and charge can't flow.

To get rid of the depletion zone, you have to get electrons moving from the N-type area to the P-type area and holes moving in the reverse direction. To do this, you connect the N-type side of the diode to the negative end of a circuit and the P-type side to the positive end. The free electrons in the N-type material are repelled by the negative electrode and drawn to the positive electrode. The holes in the P-type material move the other way. When the voltage difference between the electrodes is high enough, the electrons in the depletion zone are boosted out of their holes and begin moving freely again. The depletion zone disappears, and charge moves across the diode.

If you try to run current the other way, with the P-type side connected to the negative end of the circuit and the N-type side connected to the positive end, current will not flow. The negative electrons in the N-type material are attracted to the positive electrode. The positive holes in the P-type material are attracted to the negative electrode. No current flows across the junction because the holes and the electrons are each moving in the wrong direction. The depletion zone increases.
The interaction between electrons and holes in this setup has an interesting side effect -- it generates light! 

LED Advantages

While all diodes release light, most don't do it very effectively. In an ordinary diode, the semiconductor material itself ends up absorbing a lot of the light energy. LEDs are specially constructed to release a large number of photons outward. Additionally, they are housed in a plastic bulb that concentrates the light in a particular direction. As you can see in the diagram, most of the light from the diode bounces off the sides of the bulb, traveling on through the rounded end.

LEDs have several advantages over conventional incandescent lamps. For one thing, they don't have a filament that will burn out, so they last much longer. Additionally, their small plastic bulb makes them a lot more durable. They also fit more easily into modern electronic circuits.

But the main advantage is efficiency. In conventional incandescent bulbs , the light-production process involves generating a lot of heat (the filament must be warmed). This is completely wasted energy, unless you're using the lamp as a heater, because a huge portion of the available electricity isn't going toward producing visible light. LEDs generate very little heat, relatively speaking. A much higher percentage of the electrical power is going directly to generating light, which cuts down on the electricity demands considerably.

Up until recently, LEDs were too expensive to use for most lighting applications because they're built around advanced semiconductor material. The price of semiconductor devices has plummeted over the past decade, however, making LEDs a more cost-effective lighting option for a wide range of situations. While they may be more expensive than incandescent lights up front, their lower cost in the long run can make them a better buy. In the future, they will play an even bigger role in the world of technology.