November 19, 2009
[TechScope] California Approves TV Efficiency Regulations
The Consumer Electronics Association (CEA) responded harshly to new regulations issued by the California Energy Commission (CEC) that would regulate energy efficiency standards on televisions sold in California.
—
Staff
November 16, 2009[Ideas For Design] Diode Tester Limits Reverse Voltage And Forward Current To Protect Sensitive Junctions
Some diode manufacturers caution against using the diode tester function in ohmmeters because it could exceed the reverse-voltage and forward-current ratings of sensitive diodes. This is especially true in optical devices such as photodiodes and laser diodes. However, the circuit described here performs a simple go/no-go test on these diodes while limiting forward current and reverse voltage to safe levels (...
—
Michael Gambuzza
November 16, 2009[Electronic Design Products] Select Optimal Protection For Your VDSL-Based Telecom Circuits
A variety of over-current and overvoltage products are on the market for protecting VDSL telecommunications circuits. These include transformer line-side capacitors, transformer driver-side diodes, thyristors, gas discharge tubes (GDTs), electronic current limiters (ECLs), and combinations of all of these devices. To actively protect telecommunication systems, engineers need to understand the surges, the damage thresholds of VDSL drivers, and the...
—
Paul Wiener
November 5, 2009[Ideas For Design] Achieve MPPT Control Without Power Calculation
A maximum power point tracking (MPPT) controller circuit is extremely useful in solar photovoltaic systems for boosting power usage efficiency. The traditional MPPT design, though, requires the use of a multiplier to calculate power from source voltage and current measurements. However, it’s possible to build an MPPT controller without this multiplication stage by measuring power on the load rather than using source parameters. If we aren’t in the presence of a...
—
Giovanni Romeo
November 5, 2009[Design View / Design Solution] Take Simple Steps Toward Extreme Low-Power Design
Practicing engineers are always learning and perfecting their craft. With the demand for more portable, battery-powered devices and energy harvesting on the horizon, the requirements for even lower-power designs have gotten more challenging. At first, designers wrestled with saving milliamps, then microamps. Today, it is all about saving nanoamps. As a result, designers have to elevate their thinking to another level. Extreme low-power embedded design...
—
Steven Bible
November 5, 2009[Technology Report] Li-ion Suppliers Try To Find The Right Chemistry With Car Buyers
Since Sony introduced them in 1991, lithium-ion (Li-ion) batteries have transformed portable electronic products. Now, carmakers and would-be automotive battery suppliers are looking for a similar transformation to redefine automotive propulsion. Currently, well over 2 billion Li-ion battery cells are sold annually for consumer electronic applications, most notably cell phones and laptop computers. If cars become a significant market for Li-ion batteries, this...
—
Randy Frank
November 5, 2009[Design FAQs] Non-Isolated Point-Of-Load Regulator Modules
Analog & Power Editor Don Tuite answers some frequently asked questions about non-isolated point-of-load regulator modules, including: What is the Intermediate Bus Architecture? Functionally, what does a POL regulator comprise? How do newer packages deal with the switching inductor? Are there disadvantages to an integrated inductor? And more! Fill out this brief form to download the FAQ: ...
—
Don Tuite
November 5, 2009[Engineering Feature] A Bright Future For LED Illumination
Nearly all market forecasts paint a positive picture on LEDs being used for general illumination. Market research firm Databeans Inc. expects the market for LED lighting applications, including white LEDs, to grow an average of 23% over the next several years. Worldwide sales this year alone will total $500 million, and LED revenues will hit $1.8 billion by 2013 (see the figure). The vast majority of such sales will be for...
—
Roger Allan
November 5, 2009[Engineering Feature] White LEDs Promise Green Illumination Domination
The lighting is on the wall: Solid state is threatening to dismantle the dominion of incandescent and compact fluorescent light (CFL) sources. Illumination applications based on solid-state lighting are slowly replacing those previously ruled by the older technologies. Though very expensive to use, solid-state lighting has proven more efficient and in sync in a world where government initiatives are calling for a greener environment and less energy consumption. ...
—
Roger Allan
October 22, 2009[Ideas For Design] Calculator Provides Quick Rectifier Ripple Approximation
The standard practice for calculating the ripple voltage of a simple rectifier circuit with a reservoir capacitor (Fig. 1) is to linearize the problem. A linear approximation of the voltage across the reservoir capacitor (Fig. 2) assumes that the discharge time is equal to the period of the input sine wave, which is only approximately true for...
—
Hugo Coolens
October 22, 2009[Electronic Design Products] Select The Right Ultracapacitor Solution
Like all capacitors, ultracapacitors have a high power density. Yet unlike their traditional counterparts, electrolytic capacitors, ultracapacitors offer high energy density, allowing them to store a vast amount of energy in a small package. The capacitors that most design engineers are familiar with have very short time constants, which means their voltage cycles quickly. Ultracapacitor arrays, though, have time constants on the order of tens of seconds to...
—
Alex Patsos
October 22, 2009[TechView: Analog & Power] Tree-To-Earth pH Difference May Generate Harvestable Energy
An experimental wireless mesh network for monitoring forests for fire danger was recently demonstrated while being powered by the trees themselves during the Global Semiconductor Alliance Emerging Opportunities Expo & Conference, held earlier this month in Santa Clara, Calif. The demonstration used energy-harvesting hardware developed by a Massachusetts company called Voltree Power. The test took place at the National Interagency Fire Center...
—
Don Tuite
October 14, 2009
[Power Design] Energy Storage Industry Needs Novel Circuits And Semiconductors
Electric double-layer capacitors (EDLCs), better known as ultracapacitors or supercapacitors, are now a primary energy storage option for design engineers. During the past 10 years, we have seen the emergence of this technology, especially with the move toward “green” and more energy-efficient options. These devices have an advantage over batteries, particularly in applications requiring long life or operation in low temperatures.
—
Bobby Maher
October 8, 2009
[Editor's Notebook] $10 Million Light Bulb Prize Remains Unfunded
Philips Electronics is the first company to submit a prototype LED replacement for the common 60-W bulb in the U.S. Department of Energy’s $10 million Bright Tomorrow Lighting Contest. However, Congress has yet to appropriate funding for the prize, and questions remain about contest eligibility.
—
Don Tuite
October 8, 2009
[Power Design] Load-Sharing Power Converters Tackle Higher Output Power And Fault Tolerance
Designers parallel their power supplies to increase system power output or to provide fault tolerance. Paralleling also improves system performance. When both power supplies are load sharing, for example, the two supplies share the dissipated heat, improving reliability. Furthermore, if one power supply goes offline, the other one is coming from an already loaded state, so the perturbation on the output is not significant.
—
Tom Curatolo
October 8, 2009[Ideas For Design] Protect Current-Sense Amplifiers From Negative Overvoltage
A high-side current-sense amplifier typically amplifies the differential voltage across a sense resistor and provides an output voltage proportional to the current in that resistor. The amplifier rejects the common-mode voltage on which the sense-voltage rides. Such devices, therefore, can be used to detect overcurrent faults in a load or to make system power-management tradeoffs. Most high-side current-sense amplifiers are well suited for situations in which...
—
Prashanth Holenarsipur
, et al.
October 8, 2009[Ideas For Design] Turn A Compensated Current Sink Into A Common Emitter (CE) Amplifier
By adding only a few components, you can turn a temperature- and beta-compensated current sink into a common-emitter (CE) amplifier that maintains a stable biased operating point. This architecture is useful for building stable and device-tolerant BJT Class A amplifiers. The circuit in Figure 1 sinks a constant current (ICE3) through Q3’s collector and emitter. This design is balanced so changes in Q3’s...
—
Bill Reeve
October 8, 2009[TechView: Analog & Power] Powerline Carrier Modem Chip Facilitates Design Beyond Remote-Reading Meters
On Semiconductor’s AMIS- 49587 powerline carrier (PLC) modem does more than remotely read smart electric automatic meters. It invites a closer look at street lighting control, smart power plugs, building automation, and other applications that are part of the Smart Grid, which is a potentially disruptive technology that may offer new opportunities for design engineers (see “...
—
Don Tuite
prev. page
[1]
