Back to Power
1124 results found, displaying items 61 - 80
Energy-Harvesting Critical Success Factors
Numerous opportunities exist for ultra-low-power (ULP) energy-harvesting technologies and related power-management ICs and energy storage. The challenge in analyzing this market boils down to the sheer number of potential applications and the requirements of each market, many of which overlap with portable applications. Any “roadmap to commercialization” has to consider not only pricing, but also the technology performance metrics that must be matched to...
Energy-Harvesting Synergies
When talking about energy harvesting, the discussion tends to focus on photovoltaics or piezo beams, electrothermal devices, and other ways of turning stray energy into electrons. However, other technologies also can make energy harvesting useful. Let’s look at a few: • Wireless mesh networks: These have made it possible to place low-cost radios (the jargon is “motes”) and receptive gateways into tough-to-monitor environments. Despite their low...
The Field Of Energy Harvesting Begins To Ripen
One cannot talk about energy harvesters without discussing wireless mesh networks, sensor batteries (particularly thinfilm batteries), and supercapacitors—along with concepts of power management—nearly in the same breath. Harvesting is a complex and evolving discipline that promises rewards and challenges for engineers who want to take existing skills in new directions. Most of the technical background information in this report was derived from interviews...
The Industry Migrates To 48-V Input DC-DC Conversion
In my previous column (“Applications Drive Component Power Designs,” Sept. 11, 2008, p. 18, ED Online 19486), I contended that the application drives the selection of a specific power component—or it even forces the creation of a custom component. But, it must be admitted, there is another side of the coin. Many price-sensitive engineers see value in changing their ...
USE GDTs For Surge Protection In Broadband Digital Comm
Gas discharge tubes (GDTs) have evolved to a level of providing very reliable and effective surge protection in telecommunications systems and equipment, safeguarding against lightning and power-fault conditions. Due to their robust nature and superior electrical characteristics, GDTs have already become the preferred replacement for carbon blocks in traditional telephone-service applications. Because of their ultra-low capacitance plus low insertion and ...
Reap The Rewards Of Intelligent, Configurable Power Management
Traditionally, system designers addressed increasing price sensitivity and demands for feature-rich products by using ASICs, CPUs, dedicated microcontrollers, and memory ICs for desired product features. This hikes both the demand for power and the complexity of power management, forcing developers to consider how to support and manage multiple power-supply sources intelligently, within the strict power, thermal, and area constraints of complex modern...
Bob's Mailbox
BOB, I read your article “What’s All This Analog Engineering Stuff, Anyhow?” (Oct. 2, p. 18, ED Online 19754) I totally agree that the need for trained analog engineers is not going away. (I am not so interested in training, but in education. /rap) I have been in analog...
Low Stored Charge Separates Diode From The Pack
I n an idealized diode, no reverse current flows from cathode to anode when the device is reverse-biased. However, with real-world diodes, large amounts of stored charge can flow from the cathode—back through the anode— before the diode enters its blocking state. That stored charge is QRR, and it causes the reverse recovery current (IRR) that flows as the diode transitions from forward to reverse bias. For example, a...
Military Systems Bolstered By Building-Block Breakthroughs
Technological advances lead to tactical advantages. That’s why investments in electronic technology for military applications traditionally run high. Yet those investments can often yield useful breakthroughs as well as dramatic improvements in existing technologies. Military systems such as electronic warfare (EW), signal intelligence (SIGINT), and radar systems receive the most funding. Still, electronic building blocks such as amplifiers, display...
Stack Monitor Chips Without Isolation Concerns To Give Your Electric Car Some Zip
Okay, you want to design an electric car. Whatever kind of motor you decide on, you’re going to want to run it at a pretty high voltage. That means stacking many batteries in series to get to that voltage, which introduces interesting challenges in monitoring and charging circuits as potentials at the negative electrodes rise above system ground. This is not a new problem. But as long as it’s been confined to products like golf carts and nuclear submarines, ...
Select The Right Circuit Protection For Switch-Mode Power Supplies
Switch-mode power supplies (SMPS) continue to replace linear-regulator types in a host of applications. As the need for more efficient electronics accelerates and as a result of their size, weight, and energy-saving advantages, SMPS are being widely used in applications such as LCD TV monitors, PC/ laptop displays, portable electronics chargers, printers, DVD recorders, and even automotive electronics and industrial. Yet because these new SMPS lack the...
Energy Harvester Perpetually Powers Wireless Sensors
Energy production requires state-of-the-art monitoring systems. Of course, these systems require energy of their own to operate. For example, GE Energy recently developed a system that monitors machinery conditions for a field trial at the Nyhamna gas plant in Norway. By harvesting the vibration energy from the machines it monitors, this system’s power supply is inexhaustible. This power supply uses a microgenerator to convert vibrational energy into usable electrical energy....
Ultracapacitors Branch Out Into Wider Markets
Once the staple of brute-force power supplies and large industrial and consumer power applications, ultracapacitors are now finding their way into products of all sizes, particularly portables. Also called supercapacitors, these components are notable for capacitance values ranging into the thousands of Farads and fast charge/discharge rates. With the ability to store massive amounts of energy for long periods of time, ultracapacitors behave more like a battery ...
The Dangers Of Counterfeit Battery Packs: Answers To Reader Questions
The continuing growth of portable handheld devices has spawned a healthy selection of aftermarket battery pack suppliers. Yet aftermarket vendors may resort to activities that compromise the end-user experience or safety to make the battery packs inexpensive and attractive to those placing purchase orders for replacements. An analysis of several counterfeit batteries revealed a variety of manufacturing and design problems, and we can use these examples to answer...
Cooling Techniques Attack MPU Processing Heat
The continuing evolution toward higher-performance microprocessor units (MPUs) has revolutionized the design of computers large and small. This evolution has generally followed Moore’s law—the semiconductor industry doubles transistor density every two years while increasing performance with each new generation. Increased performance has contributed to a rise in microprocessor chip power dissipation and power density. An example of the...
Improved Nano Materials Extend Li-ion Battery Life Five-Fold
Imagine using your laptop, non-stop, flying from New York to Los Angeles and back on a single battery charge. Or, picture using your digital camera or mobile phone for days on end without recharging. QuantumSphere has just filed a patent for a nanotechnology that extends the capacity of lithium-ion (Li-ion) batteries up to five times. “We’re working on the anode side of the battery and will then begin work on the cathode side soon, with the production...
Millimeter-Wave MMIC Power Amp Operates From 18 To 33 GHz
Getting high output power and excellent linearity in a millimeter-wave amplifier is no easy trick. But Avago has done it with its AMMC/P-6333 (see the figure). This high-performance driver amplifier offers high gain and power with excellent input and output return losses. It also targets the need for broadband and eliminates the need for a negative voltage. Primary...
GaN-Based Power Device Signals Next-Gen Power Conversion
International Rectifier Corp. has successfully developed a GaN-based (gallium-nitride) power-device technology platform. It’s expected to provide improvements in two key application-specific figures of merit, on resistance and gate charge, of up to a factor of 10 compared to state-of-the-art silicon-based technology platforms. On resistance relates to how much current you can process in a unit area. It also can be related to the cost per amp of...
After All These Years, Ideas For Design Get The Royal Treatment
One of the most popular sections of Electronic Design in both print and on the Web over the years has been Ideas for Design (IFDs). We’d like to celebrate this department by dedicating this entire issue to IFDs, including insightful commentary from our editors and contributors alike. First, we’ve asked some of the industry’s top engineers, who we like to call design gurus, to reflect and write about the circuits they’ve created over the ...
Filter Trims Ultra-Precision Voltage Reference
VOLTAGE REFERENCES GENERATE WIDEBAND noise spectrums. For most semiconductor devices, this spectrum usually has a wideband “white noise” component with relatively constant power density versus frequency, and a “pink noise” or “1/f noise” component that grows with the inverse of frequency.1,2 The pink noise component rises up from the relatively flat white noise level at a point somewhere between a few hundred hertz and a kilohertz, and it increases 3 dB ...
 prev. page
1
2
3
[4]
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
next page 
|
