Falling LED Cost Yields Virtual Device Efficiency Gains

Falling LED prices are yielding an unexpected bonanza for system developers: a "virtual" gain in device efficiency,Where aluminum profiles have traditionally been the Buy Best Custom Aluminum Tube&Pipe choice of millwork shops and architectural design firms for its value and strength to weight ratio, the new green building movement has solidified aluminum sections place in all markets.You can see aluminum sections like aluminum channels, angle, trim and molding all around you. which can be as much as 50 percent, or even more in some cases.LED systems have traditionally run below the LED datasheet efficiencies. In addition to power conversion losses, LED efficiency drops as they are driven harder, and also as they run hotter.Buy Best Custom Metal Machining The former phenomenon, called "droop," follows a cube law (and is currently ascribed to a phenomenon known as indirect Auger recombination). A cutting-edge LED, when driven at its nameplate power rating, might output only 60 percent of its nameplate efficiency rating, which is often specified at reduced drive level. Similarly, other physics effects cause output to fall dramatically with increasing temperature. In a case recently brought to the attention of Greentech Media, a special-application LED lamp that used only passive fin-cooling showed a 30 percent increase in output when customers started pointing fans at the units.
High-power LED models from players such as Cree or Osram have cost as much as $4.00 in recent years. At such prices, the LED cost dominated the bill of materials for a product. Designers were under intense financial pressure to reduce the LED count by driving the devices harder. A part such as a Cree XPG might end up being driven at 1.0 or even 1.5 amps, when it could get rather higher efficiency at, say, 0.35 amps. Similarly, the cost of the LEDs left very little budget for cooling measures. Heatsinks were often undersized, and advanced measures such as heat pipes, nanomaterials, and smart fans were usually out of the question.At Strategies in Light 2012, Philips speaker Dirk Vanderhaeghen, presenting on automotive headlights in the High-Brightness Technology session track, remarked, "The end result of practical realities is that designs have come out at little more than half the theoretical efficiency of the emitters."Now, however, with 3 to 5 watt high-brightness LED prices dropping, in some cases as low as $0.Changing tires in the middle of a dark road would be difficult without these emergency lights. These leather ipad case also come in handy especially when there power interruption in the area during the evening. These portable car batteries are not hard to use, even a beginner wouldn't have a hard time using it.90 (particularly for new, cost-optimized devices such as the Cree XBD), the game is rapidly changing. Designers can convince management to use more emitters, drive them less, and allocate budget for improved cooling. CEO Kevin Wells of Lumigrow Inc., a maker of high-power LED greenhouse fixtures, states, "We can now afford to crank the LED count in a way we never could before."