What is an Incandescent Lamp : Working & Its Applications

The light bulb is an electric light source that is also technically known as a lamp that is used by consumers as a portable type of lighting like a desk lamp and a table lamp. These lamps are used everywhere around the world. But the most common type of bulb or lamp is Incandescent Lamp. These types of lamps are very old and available in a simple design.

The first inventor of an incandescent lamp is “Thomas Edison” but before his invention, there were many scientists who worked & designed a prototype. So, one of them was a British physicist namely “Joseph Wilson Swan”. From the verification, it is known that he got the first copyright for the incandescent bulb. After that, Swan & Edison combined to manufacture incandescent bulbs on a commercial scale. This article discusses an overview of an Incandescent Lamp.

What is an Incandescent Lamp?

The incandescent lamp or light or bulb is an electric light source that works through the incandescence phenomenon that means the light emission can be caused by filament heating. These lamps are available in different sizes with different voltages and wattages. Here, the voltage range of these bulbs ranges from 1.5V to 300V. The incandescent lamp symbol is shown below.

Bulb Symbol
Bulb Symbol

Incandescent lamps are the most frequently used bulbs at a reasonable cost. These lamps will glow once electrical current flows throughout a filament then they generate high brightness that is matched through large energy utilization. These bulbs are especially for task lighting and they have a light expectancy of approximately 800 hours. So these bulbs are frequently used with a dimmer in many applications.

Incandescent Lamp Construction

The construction of an incandescent lamp can be done by using different parts like a Glass bulb, Inert gas, Tungsten filament, Contact wire to foot, Contact wire to base, Support wires, Glass mount or support, Base contact wire, Screw threads, Insulation, and Electrical foot contact.

Incandescent Lamp Construction
Incandescent Lamp Construction

Glass Bulb

An incandescent lamp has a glass enclosure including a tungsten filament.

Inert Gas

The inert gas used to fill the light bulb is argon/nitrogen to reduce the evaporation of the filament. So it increases the life of the lamp by preventing the filament from falling too quickly.

Tungsten Filament

The Filament in the lamp is the thread or wire that lights up once you turn it on. The material used to make this filament is Tungsten metal because the melting point of this is very high and also heat resistant.

Contact Wires

The base of the bulb with two connections is called contact wires which provide electrical connections toward the filament.

Support Wires

Support wires are small wires which are connected to the stem to give support to the filament of the lamp.

Glass Mount or Support

Incandescent light bulbs include a glass mount that is connected to the base of the lap which permits the electrical contacts to run throughout the envelope without air or gas leaks.

Screw Thread

Most of the lamps screw into a socket. In household bulbs, a medium screw base is used which is called an Edison screw. Its diameter is 1¹⁄16 inches including seven threads for every inch.


The base of the lamp is made of brass originally & protected with plaster of Paris & after that porcelain. Nowadays, aluminum is used at the outside of the lamp & glass is used to protect the inner base so that a stronger base can be formed.

Electrical Foot Contact

At the base of a lamp or light bulb is known as electrical foot contacts which are coated with a material to protect the electricity. These two contacts will help in connecting with an electricity source.

Incandescent Lamp Working

An incandescent lamp mainly works on the incandescence principle which means the light can be generated through heat. In this type of lamp, the current is supplied throughout a thin metal filament. Once the filament is heated then it glows to generate light.

Generally, these lamps use a tungsten filament due to their high melting point. The filament in this bulb can reach 4,500 degrees F temperatures. A glass enclosure avoids oxygen within the air from reaching the filament otherwise the filament gets overheated & oxidized within seconds. This incandescent lamp works quite well in generating light. So it is suitable for a wide range of applications.

Types of Incandescent Lamp

Incandescent lamps are available in two types like gas-filled lamps and halogen lamps.

Gas-Filled Lamps

These lamps are used to generate light from an incandescent filament that operates in an inert gas ambiance. The addition of the inert gas will suppress the evaporation of the filament, which enhances the life span of the lamp.

Gas Filled Lamps
Gas Filled Lamps

These lamps use more power to attain a similar filament temperature as compared to vacuum lamps. The gas around the filament cools while evaporation is suppressed & decreases the relocation of faded tungsten toward the wall of the bulb. The maximum operating temperature of these lamps will generate more output light for each watt of i/p power to use in dangerous applications.

Halogen Lamp

The latest incandescent lamps are halogen lamps which provide several benefits over the normal incandescent lamp. The life & efficiency of these lamps decreases because of the slow fading of the filament & black deposit within the bulb.

Halogen Lamp
Halogen Lamp

By adding a small amount of halogen vapor to the filling gas restores the part of evaporated tungsten vapor reverse to the filament through a chemical reaction. The advantages of these lamps are long life, color rendition is better, decreased dimensions of miniature size of lamps.

These lamps are being manufactured in different sizes up to 5 kW. These are used at large gardens, car parks, outdoor illumination of buildings, playing fields, fountains, airport runways, etc. These lamps are used to provide lighting in factories, public halls, sport-halls, TV studios, photo films, etc.

Incandescent Lamp Circuit Diagram

The circuit diagram used to increase the life extension of incandescent light is shown below. The required components to build this circuit are: switch, VD1 1N4007, VD2 1N4007, Thyristor, Resistors R1 & R2, incandescent lamp, and capacitor.

Incandescent Lamp Circuit
Incandescent Lamp Circuit

The filament of incandescent light has a large thermal resistance and extremely small cold resistance. The impact of current supplying throughout the filament of the bulb is high so it causes the filament to burn. To overcome this problem, the switch life extension can be the best solution.

This circuit can extend the life span of the lamp very much. Once the switch ‘S’ is connected, then the voltage supply across the capacitor cannot vary suddenly, so the voltage across the capacitor is zero.
The VT thyristor limits without activating voltage, so the flow of current through the incandescent bulb used in the circuit is the half-wave current which is rectified through VD2. The bulb ‘E’ is pre-heated through darkness & the inrush current supply is extremely small.

Incandescent Lamp Vs Fluorescent Lamp

The difference between Incandescent Lamp Vs Fluorescent Lamp includes the following.

Incandescent Lamp

Fluorescent Lamp

Incandescent lamps are old. Fluorescent lamps are new.
The life span of an incandescent light bulb is about 1K hours. The life span of a fluorescent bulb is about 9K hours
The most commonly used incandescent bulb is a 60-watt bulb. To get the same brightness as an incandescent lamp, we need a 6 to 8 watt LED bulb or13 to 15-watt fluorescent bulbs.
These lamps emit mercury vapor that is dangerous to the environment. Toxic materials like mercury & phosphorus which are dangerous are used in Fluorescent lamp.
The cost of these lamps is high as compared to fluorescent lamps. The cost of these lamps is low.
These bulbs generate light by heating a filament until it begins to emit light. These lamps generate light by exciting a gas & causing it to blaze.
As compared to fluorescent lamps, their characteristics are not better. These lamps have better characteristics.
It consumes 4 to 8 times more powerful as compared to fluorescent lamps. It consumes less power.
These lamps are costly. These lamps are cheaper.
These bulbs generate warmer light. These bulbs don’t generate warmer light.
These lamps are used in table lamps, hallway lighting, accent lighting, etc. These lamps are used in classrooms, offices, cafeterias, etc.


The advantages of Incandescent lamps include the following.

  • These lamps are not costly.
  • It generates warmer colors.
  • Light output is high.
  • Manufacturing cost is less.
  • Easily dimmed with rheostats.
  • It turns on immediately.
  • In the winter seasons, these lights are very helpful in increasing the room temperature.


The disadvantages of Incandescent lamps include the following.

  • It is not energy efficient
  • The lamp lifetime is low as compared to other bulbs.
  • It is a warm light source, so needs to cool the room if required
  • It is very delicate, so we need to handle it very carefully.
  • Not suitable for large areas.
  • It generates less lumen for each watt about 5-20 lumens for every watt.


The incandescent lamp uses include the following.

  • These lamps are normally used in table lamps, desk lamps, hallway lighting, accent lighting, chandeliers, closets, etc.
  • These lamps are widely used in commercial & household lighting.

Which gas is used in the incandescent lamp?

Argon gas is used in an incandescent lamp.

What is another name of the incandescent lamp?

Incandescent lamps are also called electric light bulbs, tungsten lamps, candescent lamps, candent lamps, bulb, light-bulb, electric light, etc.

What is a tungsten light?

The tungsten light is the most common type of incandescent light bulb which is used to provide light for indoor areas like home or office.

What is an example of incandescent light?

The examples are; GLS Light Bulbs. Globe Light Bulb. Frosted Bulb. Par LED Light Bulb, Household Reflector Lamp, etc.

Thus, this is all about an overview of an Incandescent Lamp and its working with applications.
The color temperature of these bulbs ranges from white color to yellow. If it is very important to verify the color temperature of a lamp before purchase because when the color temperature of the bulb is high then the bulb is cooler, so it generates white light. Once the color temperature of the bulb is low, then the bulb generates yellow color or warm light output. Each type of bulb is very different; however, the average lifespan of an incandescent bulb has at least 1K hours. Here is a question for you, are Incandescent lamps energy efficient?