LED Drivers: Anatomy Applications and Future

By Arshi Gupta | TimesTech

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LED Drivers Anatomy Applications and Future

The LED lighting is an innovative invention of the present era. Several companies are offering LED lamps for general lighting purposes. The technology is improving at a rapid pace and nowadays, new energy efficient consumed LED lamps are available.

As comparative to other light source technologies, such as fluorescent and high intensity discharge, lighting systems using LEDs (fig.1) can be thought of as having light source (typically the individual LED sources), a ballast (for LEDs, often called the driver) and a luminaire (the surrounding materials for optical control of the emitted light along with the thermal control of the overall system). As compared to the traditional lighting system, which comprises of only a few light sources, the LED systems comprise of many individual light sources in the near future. The fig. 2 shows, several arrays that are commercially available.

An LED light bulb is used to produce light using one or more light-emitting diodes (LEDs).LED lamps have a lifespan which is a number of times longer than that of an equivalent ordinary lamp and are significantly more efficient as comparative to the fluorescent lamps along with some LED chips which could even emit up to 303 lumens per watt.

Fig.1 LED lighting system anatomy

The LEDs make use of direct current (DC), whereas the mains current is alternating current (AC) and usually at much higher voltage than the LED can accept. The LED lamps have a circuit for changing the mains AC into DC at the right voltage. These circuits comprise of rectifiers, capacitors and other electric components, which may help the lamp to get dimmed. In an LED filament lamp, the driving circuit is simplified as many LED junctions in series have approximately the same operating voltage as the AC supply.

Fig.2 LED arrays

Applications of LED lighting

  • LED lamps are utilized for general as well as lightning for special occasions. Whenever coloured lighting is required, LEDs inherently emit the light of one color without requiring any energy absorbing filters.
  • White LED lamps include more life expectancy along with higher efficiency as comparative to other lightning when used at right temperature. LED sources are compact which provides flexibility in building lighting fixtures. Moreover, it has control over the distribution of light with small reflectors or either lenses. Since the LEDs have smaller size, the control of the spatial distribution of an LED array could be controlled without any efficiency loss.
  • The LED which makes use of the color-mixing principle could transmit an extremely wide variety of colors by changing the proportions of light which are generated in each of the primary color. This helps us in constructing the LEDs of a wide range of colors. In the applications where non-directional light is needed, either a diffuser is taken or multiple individual LED emitters are utilized to emit in various directions.
  • Household LED lamps make use of standard lamp connections and shapes. These in clued driver circuitry to rectify the AC power. In addition to this, it converts the voltage to an appropriate value, usually a switched mode power supply.
  • Some specific models of LED lamps have compatibility with dimmers to be used in incandescent lamps. LED lamps also contain directional light characteristics. These are way too power efficient as compared to the compact fluorescent lamps.
  • LED tube lights have been developed to physically fit into the fixtures needed for fluorescent tubes.

LED Driver Market

The global LED driver market for lighting is expected to reach up to USD 24.98 billion by 2022.The growing adoption of LED lighting in general lighting applications, boosting demand for energy efficient lighting systems along with the acceptance of standard protocols for lighting control are the major factors driving the control of LED driver market. The constant current LED drivers are expected to be the dominant LED driver by driving method. The reason for the dominance of constant current LED drivers is because they avoid violating the maximum current which has been specified for the LEDs, ultimately avoiding any burnout or thermal runaway.

The market for LED drivers segmented on the basis of luminaire type is supposed to be dominated by Type-A lamps. Lamps with integrated modules are presumed to witness the fastest growth as fully integrated modules inside an LED system are preferred over conventionally assembled LED systems for the end users as it helps in cost cutting. Moreover, outdoor and traffic lighting is supposed to lead the end-user application of the LED driver market. Every lighting control project in street lights requires specific solutions that are appropriate for the roads such as streets, main roads and highways. The highways make use of different control strategies, a lot of projects need multiple solutions to take full advantage of energy savings.

Lack of awareness regarding the installation of LED drivers for lighting and lack of the common standards among various manufacturers are the major restraints for the upliftment of this particular market. The major players in the market are STMicroelectronics, Infineon Technology, Osram GmbH (Germany), Harvard Engineering (U.K.), Texas Instruments (U.S.), Maxim Integrated (U.S.), Macroblock Inc. (Taiwan) and others. These players adopted various strategies such as new product developments, mergers, partnerships, collaborations along with business expansions to boost their revenue in the LED driver market for lighting.

On the basis of end-use application

  • General Lighting
  • Automotive lighting
  • Backlighting
  • Others

LEDs are used in the various end-use applications such as general lighting, automotive lighting, back lighting and others. General lighting is the largest segment and is expected to drive the LED materials market owing to the increasing demand for LEDs in residential and industrial applications. The LED materials market for automotive segment is projected to witness the highest growth, driven by the demand for LEDs for exterior automotive lighting.

General Lighting

General Lighting comprises of both residential, outdoor and industrial lighting used as a lighting source at night time. LEDs in the industrial setting are involved in challenging environments such as industrial bay areas, cold storage areas and other functional areas. LEDs are ideal for outdoor lighting and are utilized for street lighting for a number of reasons which mainly involve longer lifespan and better efficiency. In addition to this, they have low power utilization and better color rendering as comparative to traditional lighting sources. Since the LEDs could be switched on instantly, therefore they have been ideal for the street lighting applications. Conventional lighting sources such as the incandescent bulbs, on the other hand side are not very efficient at converting the electricity into visible light, with only a fraction of the electricity consumed, it could be converted into useable light and the rest is wasted as heat. Although, Compact Fluorescent Lights(CFLs) are more energy efficient as compared to incandescent bulbs, CFLs have shorter life spans and they are less energy efficient than LEDs

Automotive Lighting

LEDs are used in different applications such as cabin illumination, display backlighting and indication lights in automobiles. Optimally designed interior lighting can not only increase the overall appeal of the car but it also decreases the driver’s fatigue especially during the night time driving. It can also improve the perception of the cabin space. LEDs have found widespread use in exterior lighting in automobiles. As the life of LEDs used in exterior applications has increased, it has obtained greater share of the automotive lighting market.

Backlighting

Backlighting can be used in a variety of applications such as handheld devices and mobile devices. These can also be used in televisions and computer monitors. Backlighting is expected to grow at a slower rate as compared to general lighting and automotive lighting, as this market is expected to saturate sooner as comparative to others. LEDs are used in mobile phones in order to produce a flash light. These tend to be much more versatile and can run at lower voltages as compared to the other sources. Furthermore, the LED flash can be switched on immediately which makes it one of the preferred sources of flashlight. LEDs are used in monitors for a variety of reasons. Main reasons being that they are less expensive and have a broader dimming range.

Indian LED Industry

The Indian lighting industry is on a rapid growth path. The replacement of basic and inefficient incandescent, halogen, fluorescent lamps with the modern LED lights will reduce electricity consumption. The lighting industry is expected to reduce the energy consumption of lighting from the present 18% of the total power consumption to 13% by 2020 by introducing more energy efficient products and working more closely with government to execute various schemes and awareness programmes.

Smart lights appear on a shortlist of technologies beginning to appear on many buyers must-have lists because of its ability to improve security, comfort and cut electricity costs. Smart lighting is just one piece of a total smart home revolution and is an easy entry point into the smart home.

The lighting market in India is evolving rapidly, moving from using conventional products to LEDs. This transition is driven by an increasing number of government initiatives for energy conservation, rising consumer awareness about energy- efficient products and innovative products offered by the industry that are in synchronization with the overall trend of digitization. This evolution indicates a tectonic shift in technology from electrical to electronics. In turn, this may represent a significant growth opportunity for companies offering electronic hardware or components and solutions used in LED lighting. This move to LEDs will also benefit the prototype designers, electronics manufacturing services (EMS) providers and original equipment manufacturers (OEMs)

Market at a Glance

India, being the second most populous country in the world and fifth major electricity consumer, has been experiencing an ever-widening demand-supply gap in electricity. Consequently, the market for energy efficient products such as LED lights is bound to grow. The moderately growing lighting industry will now move at a faster pace as the government is encouraging the use of LED lights in a big way. Other drivers are the smart cities project along with the increasing demand for a smart, connected lifestyle and energy efficient measures. The key factors that are expected to boost the market include falling LED prices coupled with favourable government initiatives that provide LED lights at a subsidised cost and promote LED street lighting projects. Moreover, rising consumer awareness about cost-effectiveness, enhanced life, better efficiency and inherent eco-friendly nature of LED lights will continue to drive volume sales from the industrial, residential and commercial sectors.