LED lightbulbs - how they work

We Start with the Standard Light Bulb

Over 100 years ago, Thomas Edison invented the incandescent light bulb. Simple, elegant and cheap, it quickly became the standard way to turn electricity into light, and remains in use to this day.

Enter the LED Lamp

But in spite of all its success, the incandescent light bulb does have certain disadvantages. It is not very energy efficient, and it creates lots of excess heat. In today's eco-conscious world where energy is not cheap, many people are turning to newer and more efficient light bulb designs. One of these is the LED light bulb, otherwise known as a "Light Emitting Diode" lamp.

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Light My Wire - and Be Energy Efficient!

An incandescent light bulb works by passing electricity through a small wire, or filament. The electrical resistance of the filament causes it to get so hot that it glows, producing light.

An LED, on the other hand, works by passing current through a semiconducting material, which emits photons (light) through the principle of electroluminescence. Since this design does not rely on heat to produce its light, it runs cooler and is much more energy efficient than an incandescent light bulb.

LED Light Bulb Picture

Not Your Father's LED

Light Emitting Diode technology has been around since the early 1960s. But back then LED lamps produced dim red light, making them impractical for most uses other than in small electronic devices such as calculators.

Today's LED light bulbs are far brighter and can produce white light, as well as many different colors. And multiple LED lights can be combined to achieve light output comparable to incandescent light bulbs and CFL lights.

Change is Good: LEDs vs. Other Light Bulb Types

Let's take a look at some of the main advantages of LED bulb technology.

  • Efficiency: Producing far more light per watt than an incandescent light bulb, and even more than a CFL light, the LED lamp is one of the most efficient light bulb designs in use today.
  • On-Off Cycling: Unlike fluorescent and CFL light bulbs which burn out more quickly, LED light bulbs are ideal for use in applications that are subject to frequent on-off cycling.
  • Dimming: Like incandescent light bulbs, LEDs can very easily be dimmed.
  • Temperature: LED lamps radiate very little heat. The heat that is generated is dispersed through the base of the lamp.
  • Slow failure: LEDs generally fail by a slow dimming over time, rather than burning out abruptly like incandescent light bulbs.
  • Lifetime: LEDs have a very long useful life, lasting 35,000 to 50,000 hours or longer. In contrast, fluorescents and CFL light bulbs are rated at about 10,000 to 15,000 hours, and incandescent light bulbs at 1000 to 2000 hours.
  • Shock resistance: Since LED lamps are solid-state components, they are much more shock-resistant than incandescent and fluorescent light bulbs.
  • Toxicity: Unlike fluorescent lamps and CFL light bulbs, LED lamps do not contain mercury.

More to Explore

To identify a type of bulb, use the visual guide on our Lamps Plus bulb finder page.

Or compare LEDs with the workings of other bulb technology: 

1. How an Incandescent Bulb Works

2. How a Halogen Bulb Works

3. How a CFL Bulb Works

Finally, check out this video from our YouTube channel about 3 types of LED bulbs:


Need Help With LED Light Bulbs?

Our American Lighting Association trained consultants are here for you!

Use our Lamps Plus store locator page to find a superstore location near you, or contact us for more information. Or you can shop all our energy efficient lighting options,