Total Power Supply Research Articles

A novel adaptive fully-differential GM-C filter, tuneable with a CMOS fuzzy logic controller for automatic channel equalization after digital transmissions

In this paper, an equalizer chip for digital communication channel is presented. The proposed system can equalize the CAT5e UTP cable from 20 to 400 m with a 30 MHz bandwidth. A novel structure has been used to realize GM-C filter. It uses only one GM-cell stage in contrast of conventional structures. This technique leads to improvement excess-phase, area and power consumption. An intelligent fuzzy controller tunes this filter. It changes the filter parameters based on reference eye pattern to achieve the best tuning for the filter. Layout of all circuits has been done in standard 0.35 μ m CMOS process. Total power consumption, area and power supply are 29.3 mW, 87 , 200 μ m 2 and 3.3 V.

A Low-Voltage Low-Power CMOS Analog Adaptive Equalizer for UTP-5 Cables

An analog adaptive equalizer based on a feed-forward architecture is implemented in 0.18-mum digital CMOS process. The equalizer is implemented with only digital core devices and operates at 125 Mbps over unshielded-twisted-pair category-5 cable of up to 100 m. Novel low-power circuit and system techniques resulted in 3.7-mW total power consumption and supply voltage operation as low as 1.6 V. The maximum peak-to-peak jitter at the output of the equalizer (including the transmit path driver) under all cable length is 0.33 UI. The total area of the equalizer is 27738 mum <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> .

An Integrated System for Simultaneous, Multichannel Neuronal Stimulation and Recording

Precision electronics that provide multi-electrode stimulation and recording capabilities are an important tool for the experimental study of neuronal development and plasticity. Towards this end, we present a custom analog integrated circuit (IC), fabricated in a 0.35-mum process, incorporating stimulation buffers and recording preamplifiers for multiple electrodes onto a single die. The architecture of the IC allows for arbitrary, independent configuration of electrodes for stimulation or recording, and the IC includes artifact-elimination circuitry that returns the stimulation electrode to its previous voltage following stimulation, minimizing the interference with recording. We analyze the thermal noise levels in the recording preamplifiers and experimentally measure input-referred noise as low as 4.77 muVrms in the frequency range of 30 Hz-3 kHz at a power consumption of 100 muW from a total power supply of 3.8 V. We also consider the temporal response and stability of the artifact elimination circuitry. We demonstrate that the use of the artifact-elimination circuitry with a 30-mum diameter stimulation electrode permits a return to recording mode in les 2 ms after stimulation, facilitating near-simultaneous stimulation and recording of neuronal signals. (Patent applied for, U.S. No. 2007/0178579.)

Feasibility Study of Low-Voltage DC Superconducting Distribution System

This paper describes the advantages of using superconducting cables in low-voltage DC distribution systems, focusing on total cost reduction. Demand for DC electric power has been rapidly increasing, requiring reductions in total costs and power supply system losses. The effects of using superconducting cables were investigated by changing parameters such as the current and length of cables, and it is shown that DC superconducting distribution systems are feasible even for small-capacity power systems and savings can be obtained beyond the extra cost of the superconductors and refrigeration systems. In this study, a test model of a DC superconducting distribution system, constructed by modification of an AC superconducting power transmission system, is presented and evaluated.

Microsatellite combined attitude/energy systems

We have constructed a high-temperature super conductor-magnet momentum wheel for microsatellites and propose a micro high-temperature superconductor energy storage and attitude control system for nano/pico satellites. The momentum wheel for micro satellites has a mass of 1.1 kg with an angular momentum capacity of 3.5 J sec. It occupies a volume of 12.7 cm in diameter and 5 cm in height. It operates within the restricted power budget of a microsatellite with a total power supply of only 10 watts. It consumes less than 1 watt for sustenance. The micro high-temperature superconductor flywheel for nano/pico satellites has an angular momentum capacity of 0.083 Js and stores 2.32 kJ at 530 krpm. Its energy storage capacity is approximately 45 Wh/kg with an energy density of around 370 kJ/L. The HTS systems can perform the dual function of a power/attitude control system and are ideally suited for low Earth orbit energy storage, power generation, and attitude control of spacecraft.

RE shows good signs of growth in forecast

Renewable energy provided only 2.5% of energy needs in 2000, says one of the largest oil companies in the world, but wind and solar have both increased by more than ten-fold over the last decade. “The rapid growth of wind and solar is being driven by a combination of technology advances and supportive government policy, which create a virtuous circle of expanding markets and falling unit costs,” says BP in its ‘Statistical Review of World Energy 2003.’ The analysis does not provide full data on non-hydro renewables due to “problems with the completeness, timeliness and quality of data” and a lack of clear definition of the technologies, noting that a large share of renewables is due to biomass which is a non-commercial energy source but important in emerging economies. For electricity generation, non-hydro renewables contribute 1.7% of total world output versus 1% in 1990. Nuclear increased 1.5% while consumption of hydroelectricity increased 1.3% from 2001, with nuclear and hydropower each accounting for 6% of total world energy consumption. Geothermal power generation was 6,000 MW in 1990 and expanded by 3% per year during the past decade. More than 32,000 MW of wind turbines are installed around the world, and capacity additions in the last four years have exceeded those of nuclear power, says BP in its ‘Statistical Review of World Energy 2003,’ “signalling wind's emergence as a mainstream energy source.” The largest concentrations of wind are in Germany (12,000 MW), Spain (5,000 MW), the United States (4,700 MW) and Denmark (2,900 MW). Last year, global installed wind capacity increased 7,200 MW, or 29% over 2001, and turbines generate 65 TWh of electricity each year. The share of wind in total global power supply has increased four-fold since 1996, reaching 0.4% in 2002, with Europe holding 75% of the installed capacity and 85% of recent capacity additions. This is a short news story only. Visit www.re-focus.net for the latest renewable energy news.

Crossed E×B-Fields Back-Bombardment Instability and Ion Cyclotron Heating of Gas-Discharge Plasma Streams

The article present our recent results of computer simulations and theory analysis concerning of dynamics of the crossed E×B-fields back-bombardment (BKB) instability in magnetron diodes. The concept of the BKB-instability applied to show new explanation for known experimental data of an intense ion heating in accelerated plasma streams. Main features of the BKB-instability into ion diodes are following: 1) ion magnetic insulation is d0 > ri where d0 is accelerating gap across applied magnetic field B0, ri = 5V00.5/B0 is proton Larmor radius, cm; V0 – applied voltage, kV; B0 – kG; 2) EA ≠ 0 is high electric field on self or secondary emission anode electrodes; 3) main frequency oscillation of fs = fci/2 = 0.76 B0 MHz; 4) convert power efficiency of ηB = P~/P0 is up to 50%.Radial proton HF-oscillations current density of the Jir provided by the BKB-instability excites magnetohydrodynamics waves. They are propagated in the tube plasma with azimuthal velocity v∼9 ~ 107 cm/s (Miv∼92 ~ eV0) and along the B0 with the vA ~ 4×107 cm/s -Alfven velocity. Known experimental data was demonstrated a level of the HF-oscillation power which was absorbed by proton streams by ion cyclotron heating equals up to 30% total supply power of the 1 MW.Work supported by RFFI under grant 96-02-19215.

Robust Optimal Design of Energy Supply Systems Based on Minimax Regret Criterion.

A robust optimal design method based on the minimax regret criterion is proposed to determine equipment capacities of energy supply systems so that they are robust economically against the uncertainty in energy demands. Equipment capacities and utility contract demands as well as energy flow rates are determined to minimize the maximum regret in the annual total cost while satisfying all the possible energy demands. This optimization problem is formulated as a kind of multilevel linear programming problem, and its solution is obtained by repeatedly evaluating lower and upper bounds for the maximum regret in the annual total cost. Through a numerical case study on a cogeneration system, it is shown that determining equipment capacities appropriately is more important under uncertain energy demands rather than certain ones. It is also shown that the ratio of power generating capacity to total power supply capacity decreases with an increase of the uncertainty in energy demands.

Total dose hardness assurance techniques for new generation COTS devices

Hardness assurance techniques and total dose radiation characterization data for new generation linear and COTS devices from various manufacturers are presented. A bipolar op amp showed more degradation at high dose rate than at low dose rate, which is opposite to the behavior of many other bipolar linear devices. New generation low-power op amps showed more degradation in electrical parameters with total power supply voltage of 3 V than at higher voltages. Minimum operating voltage is an important characterization parameter for newer low-power linear circuit designs.

Minimizing the mass of a potential railgun power supply

A pulsed power supply is being designed to deliver 5 MJ at 1 MA at 1 shot per second to a railgun. The supply stores energy at low current in the primary of a hydrogen-cooled transformer. A switch opens the primary circuit to transfer energy to the secondary, stepping the current up to 1 MA. The relationship between the transformer and switch is being studied to determine how the total power supply mass can be minimized. Vacuum interrupters and gate-turn-off (GTO) thyristors are used in the switch. Switch mass dominates the system, accounting for 85% of the total mass. The switch must absorb the uncoupled energy of the transformer. Low transformer coupling requires large capacitors. Even with high coupling, capacitors account for 75 to 85% of the switch mass. If transformer coupling increases, the uncoupled energy decreases, resulting in lower capacitor mass. At high transformer coupling, switch mass also depends on the turns ratio of the transformer. At lower turns ratio, a lower voltage is placed across the switch capacitors. Lighter capacitors can be used, reducing system mass. The combined transformer and switch (system) mass is minimized when transformer coupling is 0.97 to 0.99 and the turns ratio is as low as possible.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Philippine geothermal resources: General geological setting and development

The Philippine Archipelago has a composite geologic structure arising from the multi-stage development of volcanic-tectonic events evidenced by volcanism and seismic activity occurring along the active blocks of the major structural lines which traverse most of the major islands of the Philippines. The widespread volcanic activity located along the active tectonic blocks has generated regions of high heat flow, where a vast number of potentially rich geothermal resources could be exploited as an alternative source of energy. As part of a systematic geothermal development program launched by the Philippine government after the successful pilot study at the Tiwi geothermal field in 1967 by the Commission on Volcanology (now called the Philippine Institute of Volcanology—PIV), the Philippines developed four geothermal fields in the period 1972–1984. These four areas, Tiwi in Albay, Mak-Ban in Laguna, Tongonan in Leyte, and Palinpinon in Southern Negros, have already contributed 891 MW installed capacity to the total electrical power supply of the country, which is mainly dependent on oil resources. The Philippines envisaged that, with its accelerated geothermal energy programme, it would be able to achieve its target of reducing the country's dependence on imported fossil fuel by about 20% within the next decade through the utilization of its vast geothermal energy resources.

Philippine Geothermal Energy Resource: An Available Indigenous Alternative: ABSTRACT

The Philippines is indeed fortunate to be located within the West Pacific Island Arc dotted by Neogene volcanic centers. The multistage development of volcanic-plutonic events in this western part of the Circum-Pacific basin has generated regions of high heat flow where known potential geothermal resources are located. With the increasing power demands reflecting a favorable growth of the country's economy, the Philippine government embarked on an accelerated program to harness the country's geothermal energy for power utilization at the start of the energy crisis in early 70s. For a period of 10 years (1972-81), the Philippines has successfully launched a systematic and continuing program of assessing, exploring, developing, and exploiting its vast potential geothermal resources. Of the several potential areas scattered all over the archipelago, four geothermal fields have already contributed some 501 megawatts equivalent to almost 12% of the total electrical power supply of the Philippines. This paper deals with the geothermal resource development of End_Page 963------------------------------ the Philippines, a major achievement of a developing country of the Third World in the use of new and renewable sources of energy. End_of_Article - Last_Page 964------------

Nuclear power engineering in the Soviet Union

Today USSR is putting nuclear-power generation facilities into operation at the rate of about 2 million kW per year - small, when compared with the future scale and rate of expansion of nuclear-power-generating plants and the role nuclear power is to play in the country's total power supply. It appears that, by the end of the decade, the Soviet Union will be increasing the capacity of nuclear power stations at the rate of 5 to 8 million kW a year - and by the end of the century this number will probably rise to 10 million kW a year. This is comparable with the rate of growth of the capacity of all power-generating facilities. The plants are being built mostly in the European part of the country. Though their initial cost is much higher than other thermal power plants of the same capacity, they have proved adequately economical because they help save on the cost of fuel in regions lacking fuel and other energy resources. There is a marked tendency toward a rise in real cost of every additional unit of organic fuel extracted and of the electricity produced from it. The nuclear power stations commissioned in 1976 to 1980more » are to save about 50 million tons of conventional fuel. The type of reactors being built, the availability of water resources, the economics, and the siting of nuclear power plants and complexes are discussed. (MCW)« less

Microcomputer Aided Power Design For CATV Amplifier

A CATV powering program is described and a listing for the Apple II microcomputer provided. The program enables a user to rapidly and confidently compute voltages and currents for CATV amplifiers powered with either switching regulated or series regulated power supplies. Savings of both design time and energy consumption are possible since the user is able to quickly and easily optimize terminating voltages and total power supply current consumption. The operation of the program is described by way of a step-by-step run of a sample layout.

On the Heat Sources of the Arc Cathode Spot

AbstractThe main heat sources of the are cathode root are ion impact and neutralization heating at the surface and Joule (resistance) heating in the volume of the cathode. The ratio IIji between these two components of cathode power supply is investigated, it depends only on J/a (spot current divided by spot radius). In the case of Cu cathodes both components are equal if J/a = 9.17A/μm, and their contributions to the increase of the spot temperature are equal if J/a = 10.25 A/μm. This holds approximately even if the electron emission cooling is taken into account (by inclusion in the surface power supply). In the real (non‐stationary) arc spot the influence of resistive heating is rather low (between 0.1 and 1 percent of the total power supply in the case of clean surfaces), with the exception of the explosive emission processes, where the Joule heat generation is comparable with or even superior to the surface heating processes by impact or possibly electron emission (Nottingham effect). The time average of the Joule component relative to the impact power input depends on the role of such essentially non‐stationary processes in the arc spot regime. An estimate of this ratio IIj,ie basing on theoretical investigations and experimental experiences results in 0.01 ≲ IIj,ie ≲ 1.

New Method to Scale down an Operation of a Large Accelerator Power Supply

The pulse operation of an accelerator required large dynamic range of operation in a power supply. The demanded power at injection is only 0.2 % of full rating. This is conventionally obtained by changing ignition angles of thyristors otherwise by switching a small number of unit supplies in a large number of which the total power supply is composed of. The former case generates a large amount of ripples in D. C. current. At KEK accelerator the main power supply is composed of three units one of which is served for injection with new method. The new method is combination of a converter and an inverter. Two thyristor bridges have just same rating but the operation modes are opposite. The output voltages of such converter and inverter are mutually cancelled and the resultant output voltage is equivalent to one which is scaled down by only the ignition angle. The operation of such system has shown good performance properties with regard to power factor and ripples in D. C. current. The new method saved D. C. filters and dynamic filters in KEK accelerator.

A 1/H Drive for Use with Superconducting Solenoids

A circuit is presented that can be used with nearly all superconducting solenoid magnet systems to sweep the magnetic field such that equal intervals in the inverse of the field are progressed in each instant of time. The circuit produces a programming voltage that controls the total power supply current. The ideal situation of the resistanceless solenoid shunted by the virtually inductanceless persistent mode switch causes the programming voltage to assume a particularly simple form.