How do filaments work

Cool light sources , such as fluorescent lamps and LEDs , don't waste a lot of energy generating heat -- they give off mostly visible light. For this reason, they are slowly edging out the old reliable light bulb.

For more information about incandescent light bulbs and other lighting technologies, check out the links below. Light bulbs are ranked by their power -- the amount of light they put out in a certain period of time measured in watts.

Higher-watt bulbs have a bigger filament, so they produce more light. A three-way bulb has two filaments of different wattage -- typically a watt filament and a watt filament. The filaments are wired to separate circuits, which can be closed initially using a special three-way socket. The switch in the three-way socket lets you choose from three different light levels. On the lowest level, the switch closes only the circuit for the watt filament.

For the medium light level, the switch closes the circuit for the watt filament. For the brightest level, the switch closes the circuits for both filaments, so the bulb operates at watts. Sign up for our Newsletter! Mobile Newsletter banner close. Mobile Newsletter chat close. Mobile Newsletter chat dots. Mobile Newsletter chat avatar.

Mobile Newsletter chat subscribe. Prev NEXT. Household Appliances. LED lighting has been in the news and at the forefront of the lighting industry for some time now.

Operating a business is expensive, especially overhead expenses like rent, repairs, and utilities. Thankfully, there are ways to cut back. LEDs offer several advantages over traditional light bulbs, building on the best parts of their predecessors while leaving their inefficiencies. Switching to LEDs is actually a fairly simple process. Most LED bulbs are compatible with your current fixtures and can.

In many ways, buying LED bulbs is the same as buying traditional light bulbs because they both offer the same. All our lamps are branded and from quality manufacturers.

We offer guarantees on all our products and if things aren't quite right - you can return your items to us quibble free within 14 days of receipt. Lighting can be complicated, but our friendly, experienced team makes it hassle-free. Need help? Just contact us via chat, email, phone, or pop in and see us. We'll find the perfect bulb for you. You can simply replace your existing lamps or upgrade to the latest versions if you're feeling green.

Log in. February 24, Posted by Sarah Levison. What are LEDs? Globe BUY. Tubular BUY. Pear BUY. Standard BUY. Candle BUY. Blue BUY. Pink BUY. Green BUY. Red BUY. Newer Enter our Holiday Light Giveaway! Back to list. February 19, Posted by Sarah Levison. In he began working on a light bulb using carbonized paper filaments in an evacuated glass bulb. By he was able to demonstrate a working device and obtained a British patent covering a partial vacuum, carbon filament incandescent lamp.

Fifteen years later, in , Swan returned to consider the problem of the light bulb with the aid of a better vacuum and a carbonized thread as a filament. The most significant feature of Swan's improved lamp was that there was little residual oxygen in the vacuum tube to ignite the filament, thus allowing the filament to glow almost white-hot.

Swan received a British patent for his device in , about a year before Thomas Edison. Swan had reported success to the Newcastle Chemical Society and at a lecture at Sunderland Technical College in February , he demonstrated a working lamp. Starting that year he began installing light bulbs in homes and landmarks in England.

His house Underhill on Kells Lane in Low Fell, Gateshead was the first in the world to have working light bulbs installed. In he had started his own company, The Swan Electric Light Company, and started commercial production.

In , American Thomas Edison adopted Swan's incandescent light bulb using a carbon filament in an oxygen-free bulb after failures with other designs. He eventually produced a bulb that could produce light for over hours.

He lost a patent challenge in court to Swan, but American mythology continues to promote Edison and not Swan for inventing the light bulb.

The light bulb has a tungsten filament as the light emitting media. Electricity flows through a thin tungsten wire in the light bulb called the filament. The filament used in a bulb has a property called "resistance. Tungsten filament are manufactured in a way that it has a lot of resistance to electricity. As a result of this resistance, the filament heats up and starts glowing, converting electrical energy to light energy. This is because of the Joule-effect, which means that resistances heat up when an electrical current runs through them.

The electricity is converted into light and heat illuminating its surroundings. Light bulbs themselves, if used properly, are not dangerous. Although their primary function is to produce light energy, as a side effect they also produce heat.

Light bulbs are sold according to the number of watts they use — the higher the number, the brighter the bulb is, and the more energy it uses. Despite getting hot, light bulbs don't explode. However, the outer glass of a light bulb which has been on for some time is quite hot and can cause minor burns, or the broken edges might cut the skin. After hundreds of hours of operation the filament in the bulb eventually burns out and the light bulb no longer works.

The light bulb then needs replacing. It is necessary to be careful in replacing the light bulb. First, the switch for the light fixture needs to be turned off or the cable disconnected.

This is because electricity flowing into the socket where the metallic part of the bulb sits can give you a severe electric shock if you touch the inside of the socket or the metal base of the bulb while it is still partly in the socket.

In addition, if the glass breaks it is possible to get cuts. These hazards can be reduced by ensuring the bulb is cool to the touch before grasping it and by holding it firmly but not squeezing by the fattest part of the glass while rotating counter-clockwise until it comes completely loose. Although we say the filament "burns out" it actually vaporizes over time.

Some of it can be seen as darkening on the glass where it has solidified. The gas inside the glass envelope is argon, which is used because it is inert and therefore cannot unite with the filament. The brightness of the filament can be varied by changing the amount of current flowing through it the amperage , or the voltage between ends, as the amperage is related to the voltage by Ohm's law.

Also, as the filament ages, its brightness will diminish somewhat and its light will get redder and redder. Eventually, all filaments will slowly vaporize and fail due to the high temperature caused by the electricity flowing through it. By design, a light bulb has no oxygen in it.