Power Drain Research Articles

Stabilization of axisymmetric mirror plasmas by energetic ion injection

Plasmas in axisymmetric mirror devices can be made stable to MHD interchange modes by injecting energetic ions which contribute significantly to the pressure and spend a sufficiently large fraction of a bounce time in regions of favourable curvature. Pitch-angle scattering adversely affects the method by reducing this fraction. The ions must be sufficiently energetic that pitch-angle scattering is not detrimental for that part of a slowing-down time during which they contribute significantly to the pressure. The authors have solved the bounce-averaged Fokker-Planck equation, including drag and pitch-angle scattering, and calculated the energetic ion contribution to the stability integral. With specially tailored magnetic fields, the required injection energy and power drain are found to be reasonable.

A Simple Microcomputer Based on CMOS Microprocessor CDP1802

CMOS microprocessor is the most appropriate for applications where power drain and high noise immunity are important factors. Space instrumentation and automotive control are a few applications. A single-card microcomputer based on CMOS microprocessor CDP1802 and utility program UT4 which is capable of addressing 4K bytes of memory, has been designed. This microcomputer is based on a single- sided printed circuit board with a few component side connections. It has one I/O port and teletype interface as well as provision for driving loud speaker.Hex-keyboard can also be used along with this microcomputer to load the data/program using DMA facility available on the microprocessor. In that case, ROM containing utility program 13T4 can be omitted.

A travel time study from a "source" of the Usu volcano earthquake swarm.

A single mobile observation was made in Hokkaido to complement its crustal structure which had been poorly known. A swarm of Usu volcanic earthquakes, whose source region was concentrated within a diameter of 1km, was used as a source. Because of the small size of the source region and the good time keeping, errors in travel times are as little as 0.2sec, which is enough for travel time studies. Thirty-nine stations were temporarily operated on two profiles, whose length was 320km and 100km, respectively.The seismometer was basically an ocean bottom seismometer which was slightly modified for the land use. The small size, the wide dynamic range, the low power drain and the sturdiness were helpful for the efficient observations.The obtained crustal structure illustrates: (1) The granitic layer, with the velocity of 5.8km/sec, is shallow at the top and the thickness is about 20km. (2) The basaltic layer, with the velocity of 6.6km/sec, is immediately beneath the granitic layer. Its thickness is also about 20km. Hence the crust is thicker than usual compared to other regions in Japan. (3) The upper mantle velocity is 7.8km/sec.The profiles were inherently not reversed, however one of them is so planned as to be reversed by possible future earthquake swarms of Teshikaga region, which have occurred recurrently in the past.

Biomedical implantable microelectronics.

Innovative applications of microelectronics in new biomedical implantable instruments offer a singular opportunity for advances in medical research and practice because of two salient factors: (i) beyond all other types of biomedical instruments, implants exploit fully the inherent technical advantages--complex functional capability, high reliability, lower power drain, small size and weight-of microelectronics, and (ii) implants bring microelectronics into intimate association with biological systems. The combination of these two factors enables otherwise impossible new experiments to be conducted and new paostheses developed that will improve the quality of human life.

Morphology of the wings, legs and tail of three coniferous forest tits, the goldcrest, and the treecreeper in relation to locomotor pattern and feeding station selection

Morphology of the wings, legs and tail of three coniferous forest tits, the goldcrest, and the treecreeper in relation to locomotor pattern and feeding station selection

A sea floor magnetometer for the continental shelf

Measurement of temporal magnetic variations on the sea floor is desirable in order to extend the technique of geomagnetic depth sounding into the oceans. This paper describes a recording three-component sea floor magnetometer and its use in continental shelf depths. The orientation and tilt of the instrument on the sea floor are recorded using gelatine solutions to ‘freeze’ a compass card and a ball-bearing, respectively. A backing-off procedure initially nulls the magnetic field components along each of the three mutually orthogonal fluxgate sensors. Magnetic variations along each sensor axis are then recorded within a range of ± 300 nT of these nulled positions. The resolution is ± 1 nT, and with a power drain of 800 mW the magnetometer can record continuously for 30 days. The instrument capsule is moored to surface buoys for recovery in continental shelf applications. The buoys may have marker flags, radar reflectors or radio beacons attached to them to aid in relocation.

A simulation of battery energy consumption in the Tsing Hua electric vehicle

Abstract The purpose of this paper is to describe the simulation of the Tsing Hua electric vehicle based on a given driving pattern. The driving pattern in Taipei was chosen as an example. From this pattern, a power drain model was developed and thus the vehicle range and energy consumption were estimated. A good agreement between the predicted and experimental results is achieved. Furthermore, the effect of stops‐starts on the vehicle range was also studied by using the same method.

Integrated circuits for a bidirectional implantable pulsed Doppler ultrasonic blood flowmeter

The application of integrated circuits in medical implants and the complexity of these implants have increased at a rapid pace in the past few years. The need, however, still exists for a highly accurate and stable telemetry system for the measurement of blood flow. Two custom-designed ICs have been realized to resolve this problem. These ICs form the heart of a totally implantable pulsed Doppler ultrasonic bidirectional blood flowmeter; one circuit performs the basic timing functions, and the second implements low-level linear signal processing. For a small implanted package (3.8/spl times/2.8/spl times/0.8 cm/SUP 3/), these ICs must meet the stringent requirements of low-voltage operation (2.2-2.8 V), low power (<40 mW), high stability (short-term timing jitter <50 ppm), and the minimum of external components. Using a quadrature direction detecting technique, the circuits sense both positive and negative flow and produce a multiplexed telemetry signal. The approach used minimizes parts count and power drain and maximizes channel-to-channel matching in the multiplexed signal.

OPTICAL MASS MEMORIES

Optical and magnetic variants in the design of trillion-bit read/write memories are compared and tabulated. Components and materials suitable for a random access read/write nonmoving memory system are examined, with preference given to holography and photoplastic materials. Advantages and deficiencies of photoplastics are reviewed. Holographic page composer design, essential features of an optical memory with no moving parts, fiche-oriented random access memory design, and materials suitable for an efficient photoplastic fiche are considered. The optical variants offer advantages in lower volume and weight at data transfer rates near 1 Mbit/sec, but power drain is of the same order as for the magnetic variants (tape memory, disk memory). The mechanical properties of photoplastic film materials still leave much to be desired.

Primary Sodium Batteries with Beta‐Alumina Solid Electrolyte

The principal characteristics of a new class of high‐energy density primary batteries are described. These batteries employ sodium beta‐alumina as a solid electrolyte membrane that separates the reactants, sodium‐mercury amalgam as the anode, and halogens, water, or air as the oxidants. The batteries operate at or near ambient temperatures and produce very high cell voltages and energy densities. They have an essentially nondetectable rate of self‐discharge, and shelf and operating times of ten years appear feasible. A present limitation is their low power drain capability. The operating features of the sodium‐mercury amalgam anode, the cell polarization characteristics, and the discharge behavior of cells employing various liquid cathodes are described.

Sensory feedback for powered limb prostheses.

The results of these tests confirm that a prosthesis is easier to control with sensory feedback and that the proposed technique is acceptable to patients as well as to professionals working in this field. Work in this Institute is now directed toward development of the feedback system to a form suitable for inclusion in a prosthesis. This requires miniaturisation, minimisation of power drain, and, hopefully, provision for use of common electrodes for stimulation and control.

A simple, accurate voltage to frequency converter

A simple yet accurate voltage to frequency convertor is described and its performance examined. The unit requires a stable clock frequency. Conversion is linear, predictable, and practically independent of temperature to within errors of measurement (0.05%). Power drain is low (<150 mu W).

A low power voltage regulator for field instrumentation

A simple voltage regulator with a 50 mu W quiescent power drain is described. The 5 V output changes by less than 0.1% over an input voltage range of 6.5-9 V and an output current range of 0-1 mA. Temperature compensation is included. The unit appears ideal for low power field instruments.

A Low Noise, Very Low Power Charge Sensitive Amplifier for Space Applications

A charge sensitive preamplifier (CSP) followed by an amplifier with pulse shaping networks (PSA) of single differentiation-single integration type (SDSI), designed to be used with uncooled silicon nuclear particle detectors aboard space vehicles, is described. Noise performance at 5 μsec SDSI time constant was measured to be 0.91 keV FWHMSi with a slope of 43 eV/pF. The total power drain is 42 mW at + 12 V supply. The amplifier is stabilized against supply voltage and temperature variations.

Versatile Logic System for Use in Nuclear Experiments on Scientific Satellites

An improved fast low-power-drain logic system has been developed for use in nuclear experiments on scientific satellites. The basic unit of the system is an AND-NAND gate which has a response in the 10 nanosecond range, a power drain of 2.0 milliwatts and operates over the temperature range of -40°C to +80°C. In addition to providing the AND-NAND logic functions, one or more of the basic units may be connected to yield the following: a. monostable pulse generator, b. pulse generator yielding an output pulse at the leading edge of the input pulse, c. Delay, d. Threshold Detector, and e. Bistable Circuit. The system requires relatively simple circuitry for interfacing at its outputs and inputs.

Bipolar techniques approach MOS in density, cost and power drain, yet retain speed : Electronics, February (1972), p. 82

Dual threshold voltages domino design methodology utilizes low threshold voltages for all transistors that can switch during the evaluate mode and utilizes high threshold voltages for all transistors that can switch during the precharge modes. We employed standby switch can strongly turn off all of the high threshold voltage transistors which enhances the effectiveness of a dual threshold voltage CMOS technology to reduce the subthreshold leakage current. Subthreshold leakage currents are especially important in burst mode type integrated circuits where the majority of the time for system is in an idle mode. The standby switch allowed a domino system enters and leaves a low leakage standby mode within a single clock cycle. In addition, we combined domino dynamic circuits style with pass transistor XNOR and CMOS NAND gates to realize logic 1 output during its precharge phase, but not affects circuits operation in its evaluation and standby phase. The first stage NAND gates output logic 1 can guarantee the second stage computation its correct logic function when system is in a cascaded operation mode. The processing required for dual threshold voltage circuit configuration is to provide an extra threshold voltage involves only an additional implant processing step, but performs lower dynamic power consumption, lower delay and high fan-out, high switching frequencies circuits characteristics. SPICE simulation for our proposed circuits were made using a 0.18 µm CMOS process from TSMC, with 10 fF capacitive loads in all output nodes, using the parameters for typical process corner at 25 °C, the simulation results demonstrated that our designed 8-bit carry look-ahead adders reduced chip area, power consumption and propagation delay time more than 40%, 45% and around 20%, respectively. Wafer based our design were fabricated and measured, the measured data were listed and compared with simulation data and prior works. SPICE simulation also manifested lower sensitivity of our design to power supply, temperature, capacitive load and process variations than the dynamic CMOS technologies.

Stable voltage reference sources

A family of well-regulated voltage references are shown, which are readily integrable for use with emitter-coupled logic, threshold logic, or linear circuit arrays. By relying on the relatively well-matched characteristics and the temperature tracking of integrated transistors and resistor ratios, the circuit can provide a large range of output fractions of the power supply. The relationships of the circuit components for various output voltages are derived. One circuit configuration gives fractions of the power supply of less than /SUP 1///SUB 2/ while another configuration gives fractions of the power supply greater than /SUP 1///SUB 2/. Limitations of the obtainable fractions are given. Experimental results are shown for each of the two basic circuit configurations and the temperature stability is demonstrated. Well-defined stable voltages are thus derived with a minimum of components and power drain.

Instrumentation for the California Airport Noise Standards

California law requires measurement of both hourly noise level (HNL) and total daily noise exposure (Community Noise Equivalent Level, or CNEL) in the vicinity of airports. The 24-h total is determined by a formula which adds greater weight to evening and nighttime noise because of the additional annoyance experienced during those hours. An instrument is described for determining these noise levels. The hourly noise computation is performed by sampling, squaring, digitizing, and storing in memory a cumulative sum-of-the-squares of voltages proportional to the sound-pressure level. The 24-h total is obtained by additional pre-scaling, chosen to give the required evening and night weightings. The contents of both the HNL and CNEL memory registers are converted to decibels for the final output. Recently developed MOS integrated circuits make possible battery operation with very low average power drain. A novel printing head consisting of resistors deposited on glass “burns” the answers into thermochromic paper once each hour, with an additional printout at midnight for the daily CNEL. Sample measurements obtained near Logan Airport, Boston, are presented.

Potential improvements in power-speed performance of digital circuits

The characteristics of essentially zero standby power drain, reduced load capacitance, and lower supply voltage of a complementary metal-oxide-semiconductor (CMOS) digital circuit compared with a bipolar transistor circuit offer a potential advantage of 10 to 1000 times in power-speed product.

Chambres à étincelles pour spectromètre d'ions lourds cosmiques

This paper proposes a new heavy cosmic rays spectrometer with large geometry factor. This spectrometer includes more particularly two magnetostrictive wire spark chambers. The encoding system is designed for low power drain and for reducing the bulk of the information to be transmitted by telemetry. A spark chamber has been experimented on particles of various specific ionization, and from these results its behaviour with heavy cosmic rays has been evaluated.