Incandescent bulbs acquired the name because what they do is, in essence, burn (i.e. incandesce, or glow with heat). A thin tungsten filament sits inside a partial vacuum. Electricity passes through the wire and, because it offers resistance to the flow of electrons, it heats up. Quickly, the temperature rises enough to make the metal glow.

The interior of the incandescent bulb is usually coated with a diffusing material to cut down on the bright glare of a clear, glass bulb. Though, of course, there are many clear glass lightbulbs around. That doesn’t alter the basic way the bulb operates, but it does change the look.

That look is chiefly the result of the lightbulb’s ability to closely emulate the wavelengths of light given off by the sun. That’s determined to a large degree by the temperature of its surface, about 6,000 Kelvin. That’s roughly equal to 5,700 Celsius, since K = C + 273. That’s about 10,300F. That similarity is measured by something called color temperature.

Interior bulbs will often be a bit lower in color temperature, more toward the bluish than the yellow of sunlight. But don’t confuse the color temperature with the actual temperature. Incandescent bulbs typically glow at anywhere from 120F-200F (49C-93C) or higher. Water boils at 220F or 100C, so that gives you an idea how hot one can be.

By contrast, a fluorescent bulb is much cooler because it generates light in an entirely different way.

Inside the fluorescent bulb are electrodes and a thin vapor, usually mercury and a few trace gases. A voltage is applied to one of the electrodes at one end in a long tube and electrons are shot out toward the other end, bumping into the mercury atoms along the way. When they do, they give energy to its electrons. When the mercury atoms release that energy again, it appears in the form of light.

That process generates much less waste energy in the form of heat. That provides the primary reason that fluorescent bulbs are so much more efficient. In other words they can produce about the same amount of light (measured in lumens) for the same energy put into them because so much less is wasted in the form of heat.

Remember that incandescent bulbs glow because the filament is white hot. That produces a lot of heat for the amount of light given off. The result to you, the consumer, is you’re paying for a great deal more electricity over the long run to heat a wire in the case of incandescents.

On the other hand, fluorescents don’t produce the same color temperature or spectrum as incandescents. Modern CFLs come close, but they still don’t have quite the same look as an ‘ordinary’ light bulb. As a result, fluorescents have, for decades, been reserved for areas where that look isn’t regarded as so important, such as the garage.

Still, the initial cost of a fluorescent bulb is 3-10 times a standard 75 or 100-watt bulb. So, the trade off becomes electricity cost savings over the lifetime of the bulb (about 6,000-15,000 hours for fluorescent, 750-1,000 hours for incandescents) versus up front investment costs. Over their lifetime, a fluorescent saves an average of about 70% on the total cost, including purchase price and electricity bill.

While recent discussion about the environment has entered the debate, in fact the contribution of light bulbs is so small it’s hardly worth mentioning. Much larger factors, such as industrial gases, auto exhaust and other outputs are many thousands of times larger than the total produced by home lighting.

So, the old pros and cons still apply. At least, they did until LEDs entered the picture… But that’s another topic.

Enter LEDs.

Light emitting diodes have been used for over 40 years, first making their commercial appearance in watches and small clocks. But for almost that same length of time, they gave off too little light and of limited color to be useful for home illumination. No one could read or cook by a dim red light.

But LED bulbs have come a long way in recent years. While still much more expensive than an incandescent bulb, they have overcome many of the disadvantages of fluorescents. They produce bright, natural-spectrum white light that can illuminate a medium-sized area with one bulb. Actually the bulbs are made of multiple LEDs in one enclosure.

And, not the least consideration, they last practically forever. A LED bulb can burn for over 50,000 hours. Some are rated at 60,000 hours. Even if in use for as much as 10 hours per day (4 hours/day is closer to average), that works out to almost 14 years of use.

Add up all the money spent on incandescents – which last from 750-1,000 hours – and the total savings is substantial. If a 75-watt bulb costs $1 and an LED bulb costs $50, most will opt for the incandescent. But if the LED lasts 50 times longer, you break even. That doesn’t even include the time spent picking up bulbs, changing them and so forth.

Apart from the initial outlay costs, the difference in electricity use is equally dramatic, but in the LED’s favor. Keep in mind that the standard label on an incandescent is how much power it consumes, not how much light it puts out. A 60-watt incandescent bulb puts out somewhat less than 900 lumens.

A LED bulb costing roughly $50 is available that is the equivalent of a 60-watt incandescent in terms of the light given off. Yet, it consumes only 2 watts of electricity. Multiply that electricity savings by 4 hours per day over 10 years and the cost savings will far outweigh the cost of the LED bulb. At 10 cents/kWh, the total savings over 10 years is about $350. So, the bulb will pay for itself in about 18 months.

At the same time, a LED bulb runs cooler so there’s no danger of burning as so often happens with incandescents. A 100-watt bulb placed in a socket designed for a 40-watt will burn the covering plastic shade in a matter of hours or less. Also, how many times have you singed your skin when touching an ordinary bulb? That doesn’t happen with LED bulbs.

The color spectrum of LED bulbs is also superior. While incandescents do a good job or providing a reasonable emulation of natural sunlight, LEDs are far better. Incandescents are somewhat yellow, LEDs are white and much closer to the color temperature of natural daylight. And, unlike fluorescent bulbs, LEDs contain no mercury, which is hazardous if the bulb breaks.

Still LEDs have some drawbacks, apart from the higher cost. They don’t currently put out as much light per bulb as a single incandescent so it may require more than one for particular lighting applications. They light a little less than CFL bulbs.

Since LEDs are more directional, they’ll do better in reading lamps, recessed ceiling lamps and other such applications than as general ambient light. But where a long-lasting and/or always-on bulb is needed they can be very cost-effective.

A watt is a measure of power, the voltage (in volts) multiplied by the current (in amps). But because of the fact that a higher power consumption by an incandescent bulb causes the filament to become hotter, it glows brighter. That produces a brighter light.

To get a more useful comparison between incandescents and CFLs (Compact Fluorescent Lights) or LEDs, consider instead the amount of lumens the bulb is rated for. A lumen is the amount of light intensity falling on one square foot of area measured one foot away. But don’t worry, you don’t have to get out a light meter and a ruler. That work has already been done for you by the manufacturer.

For example, a 100-watt incandescent bulb will produce about 1,600-1,750 lumens. They vary for many reasons, such as the type of coating on the inside of the bulb, the alloy used for the filament and other factors. By comparison, a CFL may consume only 20 watts, yet produce about the same amount of illumination.

Similarly, a LED bulb which is actually composed of many LEDs, or light emitting diodes, within one enclosure, that produces an equivalent quantity of light may well consume only a few watts of electrical power.

From these numbers it’s easy to see why CFLs and LEDs are becoming more popular. They do cost more up front. But they consume so much less power that, as the bulb prices go down and the cost of electricity rises, they become more attractive. Over 10 years, at 10 cents per kWhr, the savings is approximately $350 for a single LED over the power many incandescents would need.

But the comparisons don’t stop with the amount of electricity consumed and the cost. There are differences among the three in something called color temperature that can form a big part of the choice to go with one or the other.

Human eyes evolved to see in natural daylight and, to an extent, moonlight which is reflected sunlight. The surface temperature of the sun is about 6,000K. (K stands for Kelvin; K = 273 + C, where C is Celsius). Because of the relationship between the temperature of the sun’s gases and light wavelengths along with the effects of the Earth’s atmosphere, the sun produces light that is perceived as approximately white. That relationship between temperature and color gave rise to the term ‘color temperature’.

Incandescents range from a yellowish to a bluish-white, but all do a fairly good job of approximating what our eyes see as ‘natural’, even at the much lower color temperature of approximately 2,700K. Old style fluorescents, because they contain mercury vapor, give off a more greenish cast. But newer CFLs manage to produce a hue much closer to natural white light. LEDs are closer than either.

So, when comparing bulbs look also for the color temperature on the packaging. That hue plays a part in the ease of reading and other tasks that home lighting is designed for. It will affect eye fatigue, and hence the possibility of headaches. It influences the general efficiency with which you can perform those tasks.

Finally, look at the bulb life ratings.

An ordinary incandescent will last from 750-1,000 hours. At the higher number, used 4 hours/day it will last about two-thirds of a year. A good CFL may last between 6,000-15,000 hours, or about 10 years if used the same amount of time. The higher cost is beginning to look like a good deal. An average LED bulb is rated at 50,000-60,000 hours. At 4 hours per day that’s over 40 years of use.

Which is best depends on your budget, your cost of electricity and how often you want or need to buy bulbs. But, as the price of CFLs and LEDs continues to come down, they look better and better, especially for those long-term applications.

The mercury atoms upon gaining energy become excited and begin moving between states of excitement and rest. This creates an electric current and results in the mercury atoms emitting ultraviolet light in short wavelengths.

This causes the coating of phosphor to emit fluorescence and this gives off a white light. Contrary to incandescent lamps, fluorescent lamps constantly need a ballast. The ballast is used to control the power flow through the lamp.

Large fluorescent lamps are of use mostly in large commercial buildings and office complexes. Incandescent lamps and bulbs at homes have been slowly but surely replaced by fluorescent lamps and bulbs which prove to be more efficient, effective, energy maximizing and cost effective.

In comparison to incandescent lamps, fluorescent lamps make use of considerably lesser amounts of power and energy. It has been noted that the power used by fluorescent lamps is one fifth to one third less than the energy used by incandescent lamps.

Fluorescent lamps are being hailed as energy saving alternatives to incandescent lamps. Incandescent light bulbs have an exceptionally slight filament assembled from tungsten. The filament is sheathed in the interior of a glass orb.

The radiant bulbs show a discrepancy on the basis of the level of consumption of power and energy production. On the basis of these differences these bulbs are categorized into separate levels such as “75 watt” and “100 watt” and so on and so forth.

The conformist incandescent light bulbs work on a comparatively straightforward principle. Electrical energy is passed from end to end of the filament. Being extremely thing the filament presents extensive intensity of resistance to the electric current. Due to this resistance, the electrical energy gets transformed to heat. This heat energy is tremendously potent and it makes the filament “white hot”. It is this heat energy which is emitted as white light.

This causes the filament to glow which lends sheen to the light being produced in the light bulb. Incandescent light bulbs have one chief drawback and this is the fact that the heat energy translates into a lot of wastage of electrical energy. It is in distinction to this theory that compact fluorescent bulbs function.

Compact fluorescent bulbs have a fluorescent pipe which has electrodes fastened to both its ends. The tube encloses a gas which consist of argon and mercury vapor. The gaseous combination allows a steady flow of electrons to pass from one electrode to another. This stream of electrons upon making contact with with the mercury atoms lends energy to them and this causes the mercury atoms to getting excited.

The mercury atoms release ultraviolet photons which come into contact with the coating of phosphor and create the visible light. Compact fluorescent bulbs are far more proficient and effectual because they produce far less heat. Compact fluorescent bulbs are confirmed to be four to six times more efficient than incandescent light bulbs.

Compact fluorescent bulbs have a greater increased lifespan as compared to incandescent light bulbs, ranging from 6,000 to 15,000 hours. Due to all the benefits it holds over incandescent lighting, fluorescent lighting has become extremely popular.

Incandescent light bulbs work on the principle of incandescence which refers to the emission of light through the transfer of heat energy via the method of radiation. Incandescent light bulbs have a very thin filament.

This filament is made up of tungsten. The tungsten filament is protected inside an outer body made of glass. This filament is heated up by passing an electric current through it. Being excessively thin, the tungsten filament offers a considerable level of resistance to the electric current passing through it.

This resistance helps in converting the electrical energy into heat energy. The heat energy is considerably influential and turns the filament white hot. It is this extreme heat which is visible as white light. As a result of this copious heat energy the filament starts to glow. This glow is the incandescence emitted by the light bulbs and this characteristic is responsible for the name “incandescent light bulbs”.

The glass casing stops the oxygen in the air from coming into contact with the filament as it would lead to oxidation of the filament. Incandescent light bulbs are available in a variety of sizes. Also the voltage of bulbs can differ greatly, ranging from as low as 1.5 volts to as powerful as 300 volts.

Some of the advantages of incandescent light bulbs are that they do not need any external equipment for regulating, and also the cost of producing these bulbs is very low. incandescent light bulbs are extremely convenient as they work well regardless of the current being used, be it Direct Current that is D.C or Alternating Current that is A.C.

Due to the extremely adaptable nature of these bulbs, they are widely used in homes as well as in offices for commercial purposes. Let us now observe the construction and structure of the incandescent light bulbs. The incandescent light bulbs are made of a glass casing which is called the envelope. This glass casing is filled with an inert gas. This inert gas works towards decreasing the evaporation of the filament.

This filament is made out of a wire of tungsten. An electric current is passed through this tungsten wire. The electric current causes the filament to heat up. The filament upon heating releases a light which forms a sort of continuous light spectrum.

Visible light is the functional and useful part of the light spectrum. However a major of the light emitted falls in the spectrum of infrared wavelengths. The glass casing of an incandescent light bulb can obtain temperatures approximating 400 to 550 degrees Fahrenheit which is the same as 200 to 260 degrees Celsius.

Compact fluorescent have a longer life span than that of the conventional incandescent bulbs and they also utilize lower amounts of energy. However, as production involves a new technology, the cost of compact fluorescent bulbs is higher than the cost of incandescent light bulbs.

The light spectrum that is radiated by compact fluorescent bulbs is also different from the light spectrum given out by incandescent bulbs. This is due to an improvement in the formula of phosphor being used in the compact fluorescent bulbs. This has resulted in the creation of a pleasing softer shade of white light as compared to the light given by incandescent light bulbs. In the 1890s, Peter Cooper Hewitt created a compact fluorescent lamp which acts as the blueprint upon which the modern compact fluorescent bulbs are built. compact fluorescent bulbs were released in the markets across the globe in the 1980s and since then they have been on an ever increasing rise in the context of popularity, acceptance and acclaim.

An important advancement in the system of fluorescent lighting was the use of electronic ballasts in the place of electromagnetic ballasts. This has helped in minimizing the level of flickering and also the slow starting up process which has always been a hindrance associated with systems of fluorescent lighting. While being compared to incandescent light bulbs, compact fluorescent bulbs often prove to be more viable because of a variety of features. For example, the lifespan of a compact fluorescent bulb is said to be between 8 to 15 times more than the lifespan of an incandescent bulb.

Incandescent bulbs on an average have a lifespan of approximately 750 hours to 1000 hours. Presenting a stark contrast to this statistic, compact fluorescent bulbs are known to have a lifespan ranging between 6,000 hours to 15,000 hours. Incandescent bulbs too can be manufactured to have an increased lifespan, sometimes as high as that of 20,000 hours. However, this feature comes at the cost of a resulting poor quality and quantity of the light produced.

When discussing the energy efficiency of the two categories of light bulbs, once again compact fluorescent bulbs manage to score above the incandescent light bulbs. It is recorded that compact fluorescent bulbs utilize an amount of energy which is can be one fifth to one third less than the energy that it is used up by the conventional incandescent light bulbs.

Most people believe that the increased cost of compact fluorescent bulbs can be an economical hindrance but in actuality, if one considers the significantly increased lifespan of compact fluorescent bulbs as well as the greatly reduced amounts of power being used up, in the long run, the initially high cost gets balanced out in terms of lower running and maintenance costs.

Incandescent light bulbs have an extremely thin filament constructed out of tungsten. The filament is encased inside a glass sphere. The incandescent bulbs vary according to the power consumption and energy output and come with different levels such as “75 watt” and “100 watt” and so on and so forth.

The conventional incandescent light bulbs function on a relatively simple principle. Electricity is conducted through the filament. As the filament is extremely thin it offers substantial levels of resistance to the electric current.

Due to this resistance, the electrical energy gets converted to heat. This heat energy is extremely powerful and it turns the filament “white hot”. It is this “white hot” energy which is released as white light. Due to the excess heat, the filament begins to glow and this lends the characteristic of incandescence to the light bulb, hence the moniker incandescent light bulbs.

Incandescent light bulbs have one major disadvantage which is that the heat energy results in a lot of wastage of electrical energy. It is in contrast to this principle that compact fluorescent bulbs function. Compact fluorescent bulbs contain a fluorescent tube which has electrodes attached to both its ends. The tube contains a gas comprising argon and mercury vapor.

The gaseous mixture allows for a steady flow of electrons from one electrode to another. This flow of electrons upon coming into contact with the atoms of mercury lends energy to them and this results in the mercury atoms getting excited. Upon vibrating between states of inertia to a state of excitement, the mercury atoms release ultraviolet photons. The ultraviolet photons come into contact with the coating of phosphor.

This creates the visible light. Compact fluorescent bulbs are far more efficient and effective because they produce far less heat. Compact fluorescent bulbs are recorded to be four to six times more efficient than incandescent light bulbs. Compact fluorescent bulbs have a higher lifespan as compared to incandescent light bulbs. They have a lifespan which ranges from 6,000 to 15,000 hours.

This presents a definite contrast to the 750 hours to 1,000 hours that make up the life span of an incandescent bulb. Compact fluorescent bulbs are also more energy efficient than incandescent light bulbs. The energy utilized by compact fluorescent bulbs is lesser by one fifth to one third of the amount used in incandescent light bulbs.

It was in the 1960s that the red LED lamps became available in the markets and by the onset of the 1970s, devices making use of the LED technology became extremely popular, heralding in a new era of lighting technologies and products.

The original LED devices had a meager output which was not very useful as the power of the devices was not enough to meet the needs of a household. However, LED lamps continued to become more and more popular and fast replaced the neon lamps and lamps which ran on power supplied by indicator-like filaments.

In comparison to neon lamps, LED lamps have a longer life period and also make use of lesser amounts of voltage. Following the red LEDs, the commercial amber/yellow LED lamps as well as the orange colored LEDs were introduced. With the growing needs for differentiation, a variety of colors were introduced, such as blue and cyan and green.

It was in the 1990s that the violet colored LED lamps were finally released in the markets. Let us take a look at the technology behind the LED lamps. It is a fact that a solitary LED diode is capable of producing only a certain amount of light and also only one color of light at a particular point of time.

The mixing of colors in order to produce multiple hues is done by using more than one LED diodes in a lamp in order to be able to produce the entire spectrum of white light which contains all the colors.

The applications of LED lamps are many. They can be used in houses for the purpose of domestic lighting, in flood lights for large areas and building, as a part of the flashlights and electric torches. LEDs can also be used for stage lighting, lighting for bicycles, illuminating billboard advertisements and also in traffic lights. A popular use of LED lamps is in art galleries where they are employed to throw soft light upon the art displays and to create an effect of low heating on the pictures. There are several advantages of using LED lamps in place of conventional forms of lighting and these include high levels of efficiency and effectiveness, an increased life span, long term durability and endurance characteristics and not to forget, the small size of the diodes which allows for flexibility and change in the designing process. The challenge faced by companies in the manufacture of LED lamps is one of cost. The technology for producing white LED diodes has not been advanced significantly enough to be able to manufacture these lights on a large scale at an economically viable cost. There are also several hindrances in the process of production itself and these glitches hamper the desired large scale production and widespread distribution as envisioned by the companies.

Bayonet bulbs are one of the greatest of modern inventions.  They are the latest bulbs designed these days which provide a new range of electricity saving products and that too at a lower price.  These bulbs are dimmable and help to save a lot of electricity.  Since these bulbs are fluorescent in nature,  they provide very bright light by consuming very less electricity.
These bayonet bulbs are a boon for those customers who look for energy saving products in the market.  These bulbs help in saving electricity,  but not at the cost of the amount of dimming light they provide.  For lesser electricity,  these provide even more brightness than the earlier CFL bulbs.

Hence these bulbs can be for directly replacing the old incandescent light bulbs.  These bulbs can be dimmed using a switch.  The range of dimness varies from 3 per cent to 100 per cent brightness.  These bulbs guarantee savings of Rupees 2000 to 3000 in the form of electricity bills from the first month of their usage.

Bayonet bulbs are generally available having 40 Watt as their maximum power.   These bulbs have a lifetime of 15,000 hours,  which is a lot as compared to a standard 100 Watt bulb’s poor life of 1000 hours.

The Bayonet bulb combines in it the Energy saving properties of a CFL bulb,  as well the property to dim the light at will and that too at a reasonable price.  These days,  when the governments are constantly appealing to the people to save energy,  and when the costs of electricity is already very high,  such bayonet bulbs will revolutionize the Electrical market.

Hence, The advantages of Bayonet bulbs over other ordinary bulbs are:

1)    It is rated at 20-40 watt,  which is very low as compared to the other local 100W bulbs.
2)    It is compatible and works well with most of the standard dimmers available in the market.
3)    It incorporates the latest Digiflux technology,  which is the best technology around these days.
4)    Dimming range is 3-100 percent.
5)    These bulbs can be switched on,  no matter how high or low the light level is.
6)    The bulbs provide constant light output in spite of frequent voltage fluctuations.
7)    The luminous output is rated at a very high 66Lm/Watt
8)    It has a very long life, of 15,000 hours.
9)    It has minimal mercury content Only 2.4 milligram.

Hence the Bayonet light bulbs are way better than the normal,  ordinary CFL or the 100 Watt light bulbs, in every aspect.  They not only help us to save energy,  but also can be dimmed up to our comforts.  They have a very long life,  and provide a lot of luminosity as well.

Those bulbs which provide the same amount of luminosity as other normal bulbs provide,  but use lesser electricity for the same are termed as Energy saving bulbs.  These bulbs may be costlier than the normal bulbs,  but in the long run,  they are very cheap as compared to ordinary bulbs , as they save a lot of electricity as well have a long life and duration.
According to a survey,  if Each Indian House hold substitutes its regular bulb with one energy saving Light bulb,  the electricity saved would be enough to shut down 5 power stations in the country.

Traditional incandescent light bulbs are really a horror.  They not only have a very short life, but also consume a lot of energy for the same light out put,  and also cost a lot of money.  Hence their substitution with efficient energy saving bulbs is a must.  Also,  from using energy saving light bulbs,  as much as 4 million tonnes of Carbon emissions to the atmosphere can be prevented.

The energy saving light bulbs use about 1/4th of the power used by traditional Incandescent bulbs and lasts up to 13 times longer than them.  Also,  these energy saving bulbs are available in in a lot of Designs and shapes and the users can select the type according to his needs and tastes.
However variations in standard Dimmer energy saving bulbs is not very common.  The initial cost of such E-Saving bulbs may be higher than the Incandescent bulbs but in the ling run these energy saving bulbs prove more cost effective.  However,  in the coming years,  the cost of such energy saving tubes and bulbs will be brought down.

But, since the Energy saving bulbs contain Mercury, their disposal still remains a problem.  They should be disposed properly and if possible, the mercury should be recycled a lot.

LED’s or Light emitting diodes can be used in regular households.  These diodes have an even longer life than the normal Energy saving bulbs and can be of as minimal power as 4 watts.  The problem with LED’s is that they do not illuminate as strongly as other energy saving bulbs do,  and hence these cant compete the energy saving bulbs now.  But in the longer run,  the LED’s are expected to replace all other types of Electronic bulbs.

Overall,  Energy saver bulbs are a boon for us,  and only a Retard shall refuse to use them in place of other expensive house hold or fancy bulbs.  These energy saver bulbs will not only reap profits for you in the future but also will help to save electricity and reduce the pollution,  in the form of carbon emissions.