Clayton B. Grantham, test engineer, National Semiconductor Corp., Tucson, Ariz., received an MBEE and MSEE in electrical engineering from the University of Arizona, Tucson. Email address: clayton.grantham@msc.com
7 results found for Clayton B. Grantham, displaying items 1 - 7
May 10, 2007[Ideas For Design] Germanium Dual-Boost Starts At 260 mV
No matter what portable power source you use, the lower the starting voltage your circuitry operates at, the better. A lower startup voltage also maximizes runtime. Furthermore, to completely discharge the power source, circuitry must run on ever-lower voltages and currents. Existing boost circuits can start up and drain a power source down to 1 V, but that still leaves too much unusable energy in a battery. Other power sources, like solar cells or micro-turbines,...
March 2, 2006[Ideas For Design] Battery Stack Drives Seven White LEDs
Illuminating more than one very bright white LED requires a choice of configuration, either series or parallel. Of course, each configuration has design tradeoffs. A parallel connection requires a lower voltage across each LED, yet ballast resistors or current sources are needed to accomplish matched light uniformity. Different levels of bias current, and thus light coming from each LED, create a disrupting light source. However, light matching with ballast resistors or current sources...
December 3, 2001[Ideas For Design] Simple LED Flasher Yields 99% Power Reduction
An LED is commonly used as a "power on" indicator for many electronic devices. For the LED to produce discernible visible light in daylight, the forward-bias current needs to be in the moderate range (10 to 20 mA). This amount of current may be too...
