The early electrical pioneers were bright enough to realize you could use an electrical current to make a wire glow. Let’s learn how do light bulbs work. If you made a thin enough piece of wire with a high enough melting point then it would glow white hot. This is because; the atoms in the metal release some light photons when their electrons become excited by the electrical current. The problem with using these glowing wires as a source of light became obvious after a couple of minutes. When the glowing wire is exposed to the oxygen in the air, the metal would quickly oxidize and disintegrate. The solution for this is light bulb.
Indeed, the light bulb as we know it was invented pretty much simultaneously on both sides of the Atlantic in the 1870s, by Joseph Swan, who was British, and by Thomas Edison, who wasn’t. And the basic idea has barely changed since. The light bulb is made out of very thin glass and contains a wire filament made from a metal chosen to have a very high melting point usually tungsten. It is wound around in a coil pattern. Early light bulbs contained a partial vacuum; the space around the filament was emptied of most of the air, reducing the potential for an oxidizing reaction to take place. More modern bulbs switched over to the use of an inert gas (one that doesn’t react with the white hot element) for the same effect. The result is a bulb that could provide up to 1000 hours of light at the flick of a switch and sometimes considerably more.
One of the light bulbs which were manufactured in 1883, just five years after the light bulb was invented, is still in daily use in the UK even 130 years later. America claims another light bulb that’s been switched on continuously for 109 years. More modern compact fluorescent ‘energy saving’ light bulbs are four times more efficient for producing the same amount of light and the new generation of LED based lights are more frugal still. Mercedes recently launched a new car that doesn’t have a single bulb in it; every bit of illumination (including the headlights) is done by LEDs.
Different types of bulbs
1. Incandescent Light Bulb.
2. Compact Flourescent Light or CFL.
3. LED light bulbs.
How does an incandescent light bulb work
The incandescent light bulb the modern version of the bulb was credited with being invented by Thomas Edison more than 125 years ago. Let’s find out how light bulb works. Once electricity is applied to the two rods as shown in the below figure.
The electricity travels up and heats the little piece of metal called a filament. It glows red hot and that creates light. The filament is made of metal called Tungsten. Tungsten can withstand a lot of heat which is a good thing because these things get hot reaching temperatures of 5000 degrees Fahrenheit. You could fry an egg on this thing. Up to ninety percent of that energy is wasted through that escaping heat. So why doesn’t the filament burn out immediately. Bulbs are skinny on the bottom and fat and round now on the top for a reason. The fatty bulby part allows the heat to spread out over a large surface area. The gas which is organ in most bulbs these days does the rest up the heat distribution.
How CFL works
Compact fluorescent lights or CFL have actually been around in their current form since the 1940’s. We probably grew up with these lights in office buildings, schools, houses. The new fangled twisty compact type was designed to fit the millions and millions of cork screw light sockets around the world. CFL is a gas discharge lamp, which simply means they use electricity to excite mercury vapors. Vapor produce light but when a metallic in rare earth phosphorus salt coating smashes into mercury it fluoresces and creates a light the human eye can see.
This light is in a different spectrum the one created by the incandescent light bulb and the softness of that light is one of the complaints people have with CFL’s. Also one of the things critics point two is the use of mercury in CFL that’s why we should never ever throw out a CFL in garbage. Please take it to certified recyclers. And the heat, well you can touch a CFL while it’s on by removing the heat portion of creating light it takes about eighty-five percent less energy to light CFL and they last up to 8 times longer.
How do LED lights work
Now the LED’s, light emitting diodes. Here I wrote it as diodes (plural) that’s because just one diode wouldn’t produce enough light. So a bunch of LED’s crammed together to get the brightness we humans need. The technology here is basically a tiny little light bulb that fits into an electrical circuit. But these lights don’t use a filament. The light is created by the moving around of electrons in a semiconductor material. Since there is no filament there is no filament to burn out making them last a very long time. You seen LED’s before they make digital clocks digital. They’re used in remote controls to send infrared signals to your TV and string millions of them together and you get in LED television. In order to create the amount of light necessary LED technicians borrowed for Edison’s 125 years old technology.
They’ve made a rounded top this allows for better distribution of light and like the Edison bulb it also helps to redistribute heat over a larger surface. The LED folks also installed the little fins at the bottom of the lamp allowing for more heat to escape and take some of the strain of the semiconductors. This results a bright light that rivals incandescent uses eighty-five percent less energy and last fifteen years or longer. I know what you’re thinking more diodes, semiconductors, fins that sound expensive. Well you’re right most LED’s that you would use in your home run about fifty dollars per bulb compare that to that of 50 cent you would pay for an incandescent and it’s a no brainer what the consumer normally would pick.