Bright ideas

LEDs and controls continue to make headway in the lighting market. Here's a look at the best and brightest. The next time you're stopped at a traffic light, look closely. Those just might be LEDs in place of your father's tried and true incandescent bulbs. Or if you're driving behind a semi, the red brakelights are probably LEDs. LEDs have been making inroads into territory traditionally held by incandescent and fluorescent bulbs, such as general-purpose lighting. They're also increasingly used extensively in good old industrial applications; as replacements for incandescent bulbs on panel indicator lights, in scanners as light sources, and in backlighting applications where they displace more costly and heat-producing electroluminescent bulbs. Here's a brief look at some LED applications that are gaining ground, as well as some novel approaches to traditional lighting setups. , Strongsville, Ohio, manufactures fiber-optic backlighting panels. One or more LEDs produce enough light to diffuse over the panel area. Fiber-optic panels are an alternative to electroluminescent types and LED arrays and light pipes which direct light to some desired area. Plus, the fiber-optic panels, lit by LEDs, don't require an inverter to convert ac to dc voltage, reducing cost and consumed power. Now, newer fiber-optic panels incorporate conductive pads for backlighting membrane switches. The pads are integrated into the switches for use in keypads, keyboards, and membrane switches. The light sources feature low-power consumption (10 to 25 mA), last up to 100,000 hr, have zero impact on the tactile feel of elastomeric keys, and can backlight a larger area than surface-mount LEDs. Conductive pads are printed on the underside of the fiber-optic panel and, when integrated with rubber keypads or membrane switch overlays, function as a switch. A conductive material on the pads is suspended above the traces on the PC board. Pressing a button,