Week 17

Progress:

4.1.1 Power Consumption

            LED light bulbs use about half the wattage of fluorescent lighting, about 9 watts of power versus 18 watts of power for a CFL light bulb. The highest efficiency of LEDs that are available in the market can reach up to 100lumen/LED and 150lumen/LED with forward voltage of 3.3V and forward current of 350mA produced by CREE and Philips respectively. With these characteristics, the energy consumption for LED lamp could be reduced by at least 50 percent compared to incandescent bulb and up to 50 percent if compared with the fluorescent lamp at the same level of luminous flux.

            According to Audi, the first car manufacture that uses LED as headlights, they stated that using LED as the low beams to produce equal amount of light that can draw less current than the traditional halogen or xenon bulbs. Typically, a high power high flux LED required only 4V 700mA LVDC supply. By using the Audi A8 as the example, they just used five LEDs for the low beams, which mean the power used is just around 14W. By comparing with the traditional D2s Xenon HID which needs 35W for the low beam lamp, hence it shows that using LED can save up to 60% power than the use of HID.

            In this research, a 9W LED bulb was compared with the 18W CFL and 36W fluorescent lamp. The bulbs were mounted on the power meter that shows the power consumption by these lamps.