What are the differences between incandescent bulbs and LED lights?

What are the differences between incandescent bulbs and LED lights?

The first difference between incandescent bulbs and LED lights lies in their lighting principles. Incandescent bulbs, also known as electric light bulbs, work by generating heat when an electric current passes through the filament. The coiled filament continuously accumulates heat, raising its temperature to over 2000 degrees Celsius. When the filament reaches incandescence, it emits light similar to red-hot iron.

The higher the temperature of the filament, the brighter the light emitted, hence the name “incandescent” bulb. However, when incandescent bulbs emit light, a large amount of electrical energy is converted into heat energy, with only a small portion being transformed into useful light energy.

On the other hand, LED lights, also known as light-emitting diodes, are solid-state semiconductor devices that directly convert electricity into light. The heart of an LED is a semiconductor chip. One end of the chip is attached to a support, serving as the negative pole, while the other end connects to the positive pole of the power supply. The entire chip is then encapsulated in epoxy resin.

The semiconductor chip consists of three parts: a P-type semiconductor, where holes dominate; an N-type semiconductor, where electrons dominate; and typically one to five periods of quantum wells in between. When a current passes through the wire and acts on the chip, electrons and holes are pushed toward the quantum wells. Inside the quantum wells, electrons and holes recombine, releasing energy in the form of photons, which is the principle behind LED light emission.

The second difference lies in the thermal radiation produced by the two types of lights. The heat generated by incandescent bulbs can be felt within a short period of time. The larger the wattage, the more heat is produced. While some of the electrical energy is converted into light, a significant portion is converted into heat. When close to an incandescent bulb, one can distinctly sense the heat it emits.

LED lights, on the other hand, generate very little heat radiation. Most of the electrical energy is directly converted into light energy. Additionally, LED light fixtures generally have lower wattage and incorporate heat dissipation structures. Compared to incandescent bulbs, LED lights produce less thermal radiation, making them cooler light sources.

The third difference lies in the quality of the light emitted by the two types of lights. Incandescent bulbs emit full-spectrum light, but the proportions of different color components are determined by the light-emitting material and the temperature. Imbalanced proportions result in color deviation, causing objects under incandescent light to appear less true to their actual colors.

LED lights, on the other hand, are primarily green light sources. LED lights operate on direct current, eliminating flickering. They also do not emit infrared or ultraviolet components, thus avoiding radiation pollution. LED lights have high color rendering index (CRI) and strong directional illumination.

Furthermore, LED lights have good dimming performance and do not cause visual errors when the color temperature changes. Being a cool light source with low heat emission, they can be safely touched. LED lights provide both comfortable lighting spaces and meet people’s physiological health needs. They serve as protective and environmentally friendly light sources that promote eye health.