One year later in October 1879 Edison successfully tested a filament that burned for 13.5 hours. This system would later become the model for our modern electric utility power distribution system of today.Įdison then resorted to a carbon-based, high-resistance, filament.

In addition, platinum was expensive, and too low in resistance which would require heavy copper conductors in Edison’s electric distribution system he was designing to supply commercial installations of his bulbs. Platinum was very difficult to work with, and prone to being weakened by heating and oxygen attack. His experiments involved the fabrication and testing of many different metal filaments, including platinum. Thomas Edison’s serious incandescent light bulb research began in 1878, filing his first patent later that year…”Improvement In Electric Lights” in October 1878. Explore this simulation to see changing temperature changes the amount of radiation given by a light bulb filament.This is an early sketch from Thomas Edison of his light bulb. The University of Colorado has graciously allowed us to use the following Phet simulation. In Canada, legislation has been place since 2014 to phase out incandescent bulbs with alternatives like halogen lights, CFL light bulbs, and LED light bulbs. This shift is due to the extreme inefficiency of incandescent bulbs as they only convert about 10% of the electrical energy they receive into visible light, with the rest being dissipated as heat. Incandescent light bulbs is still a remarkably widespread method of lighting but other types of light bulbs (like LED and CFL) are growing more popular. The light bulb filament is about 3000 K, so it gives off blackbody radiation, which (as shown below) means a lot of energy is going into heat. This effect is known as incandescence, and it is the guiding principle behind the traditional light bulb (see figure 1). As current passes through the filament, its high resistance causes its temperature to rise until it glows.

Incandescent light bulbs are devices that convert electricity into light by heating a filament, using electric current, until it emits electromagnetic radiation. The filament is the thin wire stretched between the vertical contact wires and held up by two other support wires.

How does the light bulb work