By Scott Watson

To understand more about the LEDs lighting designs, there’s a need to dig into the background aspect of light bulbs and lighting systems.  For more than 100 years now, light bulbs have been in use all over the world.    Such bulbs have undergone series of   changes   through the ingenuity of several scientists across the world.  The technology of the light bulbs and lighting systems has always   improved from one level to the other. 

Basically, the whole scenario about light bulbs can be understood from the definition of a lamp.   Actually a lamp is simply defined as a replaceable component. This can be in the form of   incandescent light bulb simply manufactured to   generate light from electricity.  Some people know the device as a light bulb while others see it as a simple lamp.  Many manufacturers of the device simply refer to it as a lamp.    In any case, let’s take a look at   the basic terminologies you need to know about light bulbs and lighting system. 

•    Incandescent 
This refers to an electric lamp that generates lights from an electrically heated filament.  They can be in the form of LEDs.  Incandescent   is seen as the very first and the most common light source all over the world.  A simple incandescent bulb works by heating a piece of metal known as filament until it shines to produce light.  When the power level is adjusted, it can generate light in different colors.  An incandescent filament usually runs at around 2850K. However, when the light is dimmed, the bulb usually uses less power. This also leads to the generation of less light.  The temperature of the filament can also be reduced in the process.  This is actually why most dimmed incandescent bulbs appear to be reddish.

Meanwhile, the glass shell in an incandescent bulb is usually used in maintaining a partial vacuum. This prevents the filament from failing and oxidizing.  In most cases, incandescent bulbs are known to be very hot when they are in use.  A 40W incandescent bulb normally has a surface temperature of about 1200C.  Little wonder why you have to wait for sometime before touching the bulb when the light is already switched off.

In any case, incandescent bulbs encounter a common failure. Their filaments usually break as they are used.  This usually occurs when they work up to 1000 hours.    Again, the filaments of such bulbs also fail when you switch them off and on severally.  Meanwhile,   it’s good to grab some safety tip about incandescent bulbs.  If for instance you unscrew any of the bulbs from its socket without turning off the switch and you go ahead to stick your finger on the socket, you can get connected with 120VAC. This can endanger your life.  Again, if you attempt holding an incandescent bulb when it’s still on and shinning, you’ll experience severe burns.

•    Halogen
Halogen bulbs also have the incandescent nature. However, there’s a difference noticed between a typical incandescent bulb and a halogen bulb.  Basically, a halogen bulb contains small amount of the halogen element. This makes its filament to burn very hot.  This usually increases the efficiency of the bulb.

Again, the filaments of halogen bulbs   last longer than the ordinary incandescent bulbs.  This is because of the halogen element used in producing them. 

•    Fluorescent
A fluorescent bulb is completely different from an incandescent bulb.  It usually has a partial vacuum   in a glass tube.  The tube usually has mercury vapor in it.  Normally, a fluorescent bulb emits electrons when it’s heated.  This goes ahead to ionize the mercury thereby forming a plasma arc at 1100K.   The mercury also goes ahead to emit UV light as it goes back to its normal state.  The UV light will then hit a phosphor which is coated in a glass tube.  This accounts for the white coating seen in most fluorescent bulbs.  The phosphor usually absorbs the UV light and also goes ahead to emit light.   The phosphor in the bulb is meant to produce the exact color light needed in the bulb.  This can come as a mixture of phosphors.  A special circuit known as ballast is usually used in running  the device. The ballast connects to the AC line as input while its output has two pairs of wires.

Most fluorescent bulbs run at mild temperature than many incandescent bulbs.  Their typical surface temperate stands at 400C. While a fluorescent bulb is on, you can easily touch it and also put it out of its fixture.  In most cases, such bulbs have electrical interlock system.   The ballast is meant to turn off   when the tube is not there. This prevents electric shock if you happen to stick your finger into the socket.

Meanwhile, a fluorescent bulb has variety of failure modes.  In most cases, its filament usually breaks after about 10,000 hours of usage.   Since the metal of the filament runs very hot, it can easily burn off and also weakens the device. Each time the fluorescent bulb is turned on, the sudden heat that comes up blows off some of the metal which may land on the glass. This accounts for the end blackening stuff seen in older tubes.

In most cases, the ballast of a fluorescent bulb may also fail. However, this can come up as from 10 to 25 years of usage.

•    Induction Lighting
This refers to a kind of fluorescent lighting meant to overcome the lifetime limits of the filaments in most fluorescent bulbs.  Filaments are not used in induction lighting.  The energy is usually introduced into the plasma through a working transformer.  The ballasts also serve as the base for the transformer while the plasma arc also has a lot to offer.  Most induction lamps can be used up to 100, 000 hours.  Their lifetime is determined by the vacuum seal on the bulb since they don’t have filaments.  Their ballasts also take years to wear out.  However such lighting systems are not very common in the world.

•    High Intensity Discharge Lamps (HID)
HIDs are basically similar to fluorescent   lamps but there’s a major difference noted.  HIDs work as gas discharge lamps that emit visible light directly instead generating UV light and converting them to light.

The above lighting terminologies are very vital when you want to know more about LEDs.  They serve as the required background knowledge that will throw more light to the lighting designs of LEDs.