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A LED to replace 50W halogens? Elsewhere in this issue (and indeed previous issues of SILICON CHIP) we rail against the huge energy wastage of all-too-popular halogen downlights). Perhaps their days are numbered . . . J ust over 12 months ago (June 2006), we brought you news of a (then!) super-bright LED whose brightness exceeded that of a 20W halogen. With rapid advance   ments in the LED field, the next brightness hurdle – that of the 50W halogen – has been jumped. Osram has developed a light-emitting diode (LED) spotlight that achieves an output of more than 1000 lumens. That’s brighter than a 50W halogen lamp, making the device suitable for a broad range of general lighting applications. The Ostar Lighting LED, scheduled for release within months, can provide sufficient light for a desk from a height of two metres, for example. Its small size also enables the creation of completely new lamp shapes. A lumen (lm) is the unit of measurement for the amount of light emitted by a light source. A typical 60W light bulb emits 730lm, while a 50W halogen lamp has an output of approximately 900lm. To achieve the 1000lm output of the tiny Ostar Lighting LED, Siemens’ Osram subsidiary managed to integrate six high-performance LED lighting chips into the unit’s small housing. Each chip has an area of only one square millimetre, which makes for very concentrated overall luminosity. Different types of LEDs are used today in various areas, for example as background lighting in cell phone displays, as well as in car turn-signal lights, brake lights and daytime running lights. They’re also rapidly replacing incandescent bulbs in traffic control lights. The benefits are obvious. The LEDs are extremely small and consume little energy because they efficiently convert electricity into light. The Ostar Lighting LED, for example, produces 75 lumens per watt at a current of 350mA. By comparison, a standard incandescent lamp, at around 12-15 lumens per watt, converts only a fraction of the electricity supplied into light. The rest is lost as heat. Halogen downlights are marginally better at about 18-25 lumens per watt. An even better idea of the efficiency of the Ostar LED is that its 12V, 50W halogen competitor requires a 4A supply. In addition, LED lamps last around 10 times longer than halogen lamps and 50 times longer than incandescent lamps, thereby helping to significantly reduce maintenance costs. They contain no lead or mercury, which makes them very environmentally friendly. Until now, LEDs have been unsuited for room lighting because they weren’t bright enough. The Ostar Lighting LED marks a big step forward – we could soon see lots of LEDs in home lighting. siliconchip.com.au Osram has developed a LED spotlight that achieves an output of more than 1000 lumens for the first time. That’s brighter than a 50W halogen lamp but without the heat, thereby making the device suitable for a broad range of general lighting applications. The Ostar Lighting LED will be launched on the market this year. Osram has already supplied a Migros supermarket in the Swiss canton of St. Gallen with 18,000 Golden Dragon LEDs, which have a lower output than the Ostar Lighting units. These LEDs emit neither UV rays nor heat, which means they have virtually no negative impact on delicate grocery items such as milk, meat, fruit and vegetables. SC July 2007  15