Week 29

FYP presentation on 25th April 2013 at Gemilang Hall.

Poster:

Week 28

Progress:

Cost Comparison
Types of lighting sources	Fluorescent tube (Philips TLD 36W/ 54-765)	Fluorescent tube (Philips TLD 18W/ 54-765)	CFL (Philips E27)	LED (Philips E27)	LED (Generic - downlight)	LED (Generic - tube)
Purchase Price (RM)	2.80	4.50	13	45	30	68
Electricity Usage (Watt)	36	18	18	9	5	18
Starting Time (sec)	<5	<5	<5	instant	instant	instant
Lumens (lm)	2600	1030	1100	600	900	900
Lumens/Watt	72	57	61	67	100	100
Color Temperature (Kelvin)	6200	6200	6500	6500	3000	3000
Color Rendering Index
Lifespan (hrs)	13000	13000	8000	15000	25000	25000
Bulb Cost Over 10 years (12 hours usage)	RM 9.43	RM 15.16	RM 71.18	RM 131.40	RM 52.56	RM 119.14
Energy Cost Over 10 years (21.8cents/kWhr)	RM 343.74	RM 171.87	RM 171.87	RM 85.94	RM 47.74	RM 171.87
Total	RM 353.17	RM 187.03	RM 243.05	RM 217.34	RM 100.30	RM 291.01

Week 27

Progress:

4.5 Limitations of Using Compact Fluorescent lamp

4.5.1 On/Off Cycling

CFLs are sensitive to frequent on/off cycling. their rated lifetimes of 10,000 hours are reduced in applications where the light is switched on and off often.

4.5.2 Dimmers

Dimmable CFLs are available for lights using a dimmer switch but not all CFLs can be used on dimmer switches. Using a regular CFL with a dimmer can shorten the bulb lifespan.

4.5.3 Outdoor Lighting

CFLs can be used outdoors but should be covered or shaded from the elements. Low temperatures may reduce light levels.

4.5.4 Retail Lighting

CFLs are not spot lights. Retail store display lighting usually requires narrow focus beams for stronger spot lighting. CFLs are better for area lighting.

4.5.5 Mercury Content

CFLs contain small amounts of mercury which is a toxic metal. This metal may be released if the bulb is broken or during disposal. Mercury is a toxic metal associated with contamination of water, fish and food supplies and can lead to adverse health effects. A CFL bulb generally contains an average of 5mg of mercury. A power plant will emit 10mg of mercury to produce the electricity to run an incandescent bulb compared to only 2.4mg of mercury to run a CFL for the same amount of time. The net benefit of using the more energy efficient lamp is positive and this is especially true if the mercury in the fluorescent lamp is kept out of the waste stream when the lamp expires. The mercury in CFL poses no threat while in the bulb but if its broken, one should open a window and leave the room for 15 minutes and more, use a wet rag to clean it up and put all of the pieces and the rag into a plastic bag and lastly place all materials in a second sealed plastic bag and call the nearest recycling center to see if they accept the material.

Week 26

Progress:

4.4 Potential of Using Compact Fluorescent lamp as the Lighting Source

4.4.1 Reduces air and water pollution

Replacing a single incandescent bulb with a CFL will keep a half-ton of CO2 out of the atmosphere over the life of the bulb. Saving electricity reduces CO2 emissions, sulfur oxide and high level nuclear waste.

4.4.2 High quality light

Newer CFLs give a warm, inviting light instead of the cool white light of older fluorescents. They use rare earth phosphors for excellent color and warmth. New electronically ballasted CFLs do not flicker or hum.

Week 25

Progress:

4.3 Characteristics of Compact Fluorescent lamp

Compact Fluorescent lamps (CFL) are available in a variety of styles or shapes. Come have two, four or six tubes. Older models and specialty models have separate tubes and ballasts. Some CFLs have the tubes and ballast permanently connected. This allows you to change the tubes without changing the ballast. Others have circular or spiral-shaped tubes. In general, the size or total surface area of the tube determines how much light the bulb produces.

4.3.1 Efficient

CFLs are four times more efficient and last up to 10 times longer than incandescent. A 22 Watt CFL has about same light output as a 100 Watt incandescent. CFLs uses 50-80% less energy than the incandescent.

4.3.2 Versatile

CFLs can be applied nearby anywhere that incandescent lights are used. Energy efficient CFLs can be used in recessed fixtures, table lamps, track lighting, ceiling fixtures and porch lights.

Week 24

Progress:

4.2 Potential of Using LED as the Lighting Source

4.2.1 Wide Color Range

The wavelength for the LED ranges from small to large scales. As LED have different wavelength, by using a multiplexing technology to control RGB LED package, it can generate a full color scales.

4.2.2 Small Size

            The sizes of LEDs are small and it can be arranged to any pattern for different applications. The sizes for the LEDs are varying from the smallest Organic LED (OLED) of 1cm type. By such a small package size, it gives a wide area for the lighting engineers to design their own applications.

4.2.3 Easy to Control

            LED operates at low voltage with DC source. Hence, the lighting intensity can be easily driven digitally by using high frequency pulse width modulation (PWM).

4.2.4 Mercury-free

There is no mercury used in the manufacturing of LEDs.

4.2.5 Cost-effective

Although LEDs are initially expensive, the cost is recouped over time and in battery savings. LED bulb use was first adopted commercially where maintenance and replacement costs are expensive. The costs of new LED bulb have gone down considerably in the last few years and are continuing to go down. Today, there are many new LED light bulbs for use in ho mans the cost is becoming less of an issue.

Week 23

Progress:

4.1.9 Lifespan / Durability

Since LEDs do not have filament, they are not damaged under circumstances when a regular incandescent bulb would be broken. Because they are solid, LED bulbs hold up well to jarring and bumping. LED bulbs last up to 10 times as long as compact fluorescents and far longer than typical incandescent.

Week 22

Progress:

4.1.5 Color Rendering Index (CRI)

Color Rendering Index represents he quality of light and its faithfulness to render colors correctly that is to enable human to perceive colors. The ideal CRI is 100 and some bulbs approach this level. LED bulbs rating ranges from 70 to 95.

Light Source	CRI Index
Fluorescent Lamp	52-95
Incandescent Lamp	~100
HID (mercury)	15-55
LED	0-80

Table 4.2: CRI index for lighting devices

4.1.6 Correlated Color Temperature (CCT)

Correlated Color Temperature is the measure used to describe the relative color appearance of a white light source. CCT indicates whether the light source appears more yellow or gold or orange or more blue, in terms of the range of available shades of white. CCT is given in Kelvin (unit of absolute temperature). 2700K is Warm and 5000K is Cool.

4.1.7 Lumens

Lumen is a unit of standard measurement that is used to describe the amount of light contained in an area as perceived by the human eye. The more lumens, the brighter the light.

4.1.8 Luminous Flux

Luminous Flux is the flow of light measured in lumens. With light bulbs, it provides an estimate of the apparent amount of light the bulb will produce. Depending on the application, much of an incandescent light is wasted because it is emitted in every direction. LED bulbs, on the other hand, put out directional light, sending all of the light exactly where it is needed.

Week 21

Progress:

4.1.4 Dimming Options

            Originally LED lights could not be dimmed and would not work with standard dimmer switches. However, many types of Led lighting including white and RGB strip lights come in dimmable models that can be dimmed in two main ways; with LED dimmer switches or using dimmable LED drivers and standard dimmer switches. These two options offer smooth, seamless dimming from 0% to 100% brightness and that means that anyone can install conventional dimmable LEDs or even dimmable color-changing LEDs anywhere that they want LED lighting and the option to dim it.

            One of the benefits of dimmable LEDs and LED dimmers are that they use a different dimming technology than most traditional dimmers and they interact with LED technology itself in such a way that dimming LEDs has absolutely no adverse impact on the life of lights. On the other hand, dimming has little to no benefit in terms of decreased energy consumption, unlike dimming incandescent bulbs which can cut their energy usage. The other possible dimming methods for LED are by using high current rheostat or by using the PWM to control dimming.

Week 20

Progress:

4.1.3 Efficiency

LED light bulbs use only 2-17 Watts of electricity. LED bulbs used in fixtures inside the home save electricity, remain cool and save money on replacement costs since LED bulbs last so long. Small LED flashlight bulbs will extend battery life 10 to 15 times longer than with incandescent bulbs.

LEDs do not provide ultraviolet radiation and infrared radiation. The only loss for LED is the heat loss. Industry experts expect continued improvement in light output and cost effectiveness of LED lighting. LED manufacturers expect that LED efficacy will ultimately be achieving a goal of 150 to 200 lumens per watt in the future.

LEDs also have favorable operating characteristics where the light do not require any strike time which means it is instantly come on and off without effect of lifetimes.

Light Source	Loss in Radiation (%)	Heat Loss (%)
Incandescent Lamp	81-86	5-6
Fluorescent Lamp	30-32	44
HID (mercury)	62-65	16-22
LED	0-0.2	80-88

Table 4.1: Losses for different lighting devices

Week 19

* mid sem break *

Week 18

Progress:

4.1.2 Working Topology

            LEDs use solid state semiconductor technology similar to those used in modern microprocessors. The parts of an LED are two semiconductor materials layered on substrate and powered by a low direct-current voltage; electrons released from the negative n-type layer combine with holes from the positive p-type. When electron-hole pairs are combined, a photon of light is emitted from the active layer. The semiconductor is often called a chip. The chips can be packaged in a variety of optical refracting forms to enhance the light output. The most common type has been the bullet-shape (T-1) that encases the chip in a 5mm epoxy package. Current advances in chip packaging configurations now allow for improved directional control of the light output, better thermal management and overall flexibility in design of light fixtures.

Incandescent lamp creates light by heating a thin filament to a high temperature above 2500 °C and then turns the heat to the visible light. Hence, over 90% for the energy is transfer to the invisible infrared light or heat.

To let the fluorescent lamp and the halogen lamp glow up, the energy is used to produce ultraviolet light and then the electricity is passed across the tube through the mercury vapor to make the phosphor coating glow or fluorescent. Hence, the efficiency for the fluorescent lamp will be decreased during the process of the generation of the ultraviolet light and converting the ultraviolet light to the visible light.

                The working topology for LEDs is much simpler. The simplest topology is by using a current limit resistor to control the current passing through the LEDs. Developing the DC-DC converter with current regulation can make the power circuit more reliable.

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. 

Week 16

Progress:

RESULT AND ANALYSIS

4.1 Characteristics of the LED lamp

LED lamps are used for both general and special purpose lighting. Where colored light is needed, LEDs naturally emitting many colors are available without filters. This improves the energy efficiently over a white light source that generates all colors of light then discards some of the visible energy in a filter.

White-light LED lamps have longer life expectancy and higher efficiency than most other lighting. LED sources are compact, which gives flexibility in designing lighting fixtures and good control over the distribution of light with small reflectors or lenses. Because of the small size of LEDS, control of the spatial distribution of illumination is extremely flexible and the light output and spatial distribution of a LED array can be controlled with no efficiency loss.

LED lamps have no glass tubes to break and their internal parts are rigidly supported, making them resistant to vibration and impact. With proper driver electronics design, an LED lamp can be made dimmable over a wide range, there is no minimum current needed to sustain lamp operation.