Simple Power Supply Research Articles

Scalable nanomanufacturing of millimetre-length 2D NaxCoO2 nanosheets

A novel, scalable nanomanufacturing technique is reported for batch fabrication of nanoscale-thick Na0.7CoO2 nanosheets. The nanomanufacturing technique is a high-yield, bottom-up process that is capable of producing tens of thousands of nanosheets stacked into a macro-scale pellet. The nanosheets are uniform in length and shape with very high crystal anisotropy. The nanosheet thicknesses can be 10–100 nm while their lengths can measure up to 1.8 mm long. The typical dimension ratios are highly anisotropic, at 10−5:1 : 1 (thickness:length:width). X-ray synchrotron studies indicate that the 2D crystals are stacked in a turbostratic arrangement with rotational misalignment with respect to the stacking axis. The stacked nanosheets are readily delaminated into very large (350 μm × 150 μm × 100 nm) free-standing 2D crystals. The novel nanomanufacturing technique is based on sol–gel and electric-field induced kinetic-demixing followed by a brief high temperature treatment, thus providing an efficient means of large scale crystal growth requiring only a simple furnace and power supply. Evidence shows that the demixing process increases the concentration of Na ions and that demixing is necessary to produce the millimetre-length nanosheets. Electric field induced kinetic-demixing is successfully performed at low temperatures (<300 °C), which is more than three times lower than past kinetic-demixing temperatures.

A simple and compact blue diode laser powered excitation source for fluorescence detection in capillary electrochromatographic microchip separation

A simple and compact fluorescence excitation source was prepared using a 405nm blue laser diode module and characterized in capillary electrochromatographic or capillary electrophoretic microchip separation. An inexpensive blue laser diode module with a tiny focusing lens was simply mounted at the center of an aluminum block on a miniature linear motion guide for heat dissipation and position control. A slit unit has a series of fifteen laser-machined slits with 1mm space along the direction of the separation channel of the microchip above this unit. The laser beam was focused through a slit with 50μm width to the separation channel at the position of a desired length. Although the excitation source unit was connected to a simple current controlled power supply, it was stable with 0.1% drift per hour and 1.3% (1σ) fluctuation in intensity. This simple excitation source can be prepared easily with inexpensive minimum optical components and mounted with a microchip on the stage of an ordinary fluorescence microscope for daily separation studies using a CE or CEC microchip. The applicability of the excitation source was evaluated with FITC-amino acid derivative mixtures using a polymer based CEC microchip packed fully with submicron silica beads in its microchannel.

Buck/half-bridge input-series two-stage converter

This study presents a concept of connecting two-stage DC–DC converters in an input-series connection. An application example is discussed in detail where the first stage utilises two series connected buck converters that have reduced voltage stress. A single second stage is a half-bridge converter and is able to regulate the charge balance of the first stage. The benefits of the topology include: reduced primary switch voltage stress, simple self-driven synchronous rectification for wide input voltage range, self-voltage balancing on intermediate bus capacitors and simple housekeeping power supply. Further, the topology exhibits an unusual ripple match concept that can be utilised to suppress the current ripple of the second stage. Based on the detailed analysis, prototypes with 500–700 V input and 5 V/30 A output are built. Experimental results verify the principle and performance of the new topology.

A Large-Scale, Wireless Electrochemical Bipolar Electrode Microarray

We report a microelectrochemical array composed of 1000 individual bipolar electrodes that are controlled with just two driving electrodes and a simple power supply. The system is configured so that faradaic processes occurring at the cathode end of each electrode are correlated to light emission via electrogenerated chemiluminescence (ECL) at the anode end. This makes it possible to read out the state of each electrode simultaneously. The significant advance is that the electrode array is fabricated on a glass microscope slide and is operated in a simple electrochemical cell. This eliminates the need for microfluidic channels, provides a fabrication route to arbitrarily large electrode arrays, and will make it possible to place sensing chemistries onto each electrode using a robotic spotter.

Simple DC Power Supply

I you want to make a neon-bulb relaxation oscillator,1 but don’t have a dc power supply that will produce the required 80 V or so, here is another option. I created a 95-V battery to use with a relaxation oscillator by connecting ten 9-V alkaline batteries in series (see Fig. 1). The batteries snap together like Lego bricks, and the leads on the end batteries each use half of a twoterminal battery connector (see Fig. 2). This dc power supply is safer and more convenient than one running on 110 VAC.

Current-Fed Dual-Bridge DC–DC Converter

A new isolated current-fed pulsewidth modulation dc-dc converter-current-fed dual-bridge dc-dc converter-with small inductance and no deadtime operation is presented and analyzed. The new topology has more than 3times smaller inductance than that of current-fed full-bridge converter, thus having faster transient response speed. Other characteristics include simple self-driven synchronous rectification, simple housekeeping power supply, and smaller output filter capacitance. Detailed analysis shows the proposed converter can have either lower voltage stress on all primary side power switches or soft switching properties when different driving schemes are applied. A 48-V/125-W prototype dc-dc converter with dual output has been tested for the verification of the principles. Both simulations and experiments verify the feasibility and advantages of the new topology

Characteristics of end Hall ion source with magnetron hollow cathode discharge

An end Hall ion source with magnetron hollow cathode discharge is described. The source is suitable for high current, low energy ion beam applications such as Hall current plasma accelerators. The end Hall ion source is based on an anode layer thruster with closed drift electrons that move in a closed path in the E×B field. Only a simple magnetron power supply is used in the ion source. The special configuration enables uninterrupted and expanded operation with oxygen as well as other reactive gases because of the absence of an electron source in the ion source. In our evaluation, the ion beam current was measured by a circular electrostatic probe and the energy distribution of the ion beam was measured by a retarding potential analyzer (RPA). An ion beam current density of up to 10mA/cm2 was obtained at a mean ion energy of 100–250eV using Ar or O2. The ion source can be operated in a stable fashion at a discharge voltage between 200 and 500V and without additional electron triggering. The discharge power of the ion source can be easily changed by adjusting the gas flow rate and anode voltage. No water cooling is needed for power from 500W to 2kW. The simple and rugged ion source is suitable for industrial applications such as deposition of thin films with enhanced adhesion. The operational characteristics of the ion source are experimentally determined and discussed.

A Simple Energy Recovery Circuit for High-Power Inverters With Complete Turn-On and Turn-Off Snubbers

This paper presents and analyzes an active energy recovery circuit for the inductive turn-on snubber and capacitive turn-off snubber used on high-power gate-turn-off thyristor inverters. The circuit performs as a simple switched-mode power supply and recovers the inductive and capacitive snubbers energy induced in power inverters back into the dc rail with the aid of an extra switch. The features and operation of the proposed circuit are given and supported by PSpice simulations and experimental results.

Compact, high voltage power supply for the lab-on-a-chip.

The design, construction and operation of a simple, inexpensive and compact high voltage power supply (HVPS) for use in conjunction with a simple cross capillary electrophoresis microchip is presented. The microchip HVPS utilizes a single high voltage power supply (15 kV), a voltage-divider network, to give the voltages necessary to operate a gated injection valve, and two high voltage relays for switching between the open and closed gate sequences of the injection. In order to accommodate the application of different simple cross microchip dimensions, a set of equations for defining the resistor network and ensuring proper gate performance are presented.

エンジン・発電機制御装置ＧＣＰの紹介

The GCP Series generator set control provide total control of engines, generators and power systems for medium to large applications with multiple generator sets. The GCP's compact design encompasses multiple functions for direct control of engine governor/actuators and generator AVR; it also directly protects the engine-generator itself, generator power bus, load bus and system. The GCP is applied to distributed/on-site power generation unit to economize on system power consumption and simple power supply preparation for emergency or stand-by use, as well as to meet cogeneration requirements or as an additional power supply supplementing existing generator sets.

Ion source with closed drift anode layer plasma acceleration

Several versions of ion sources with closed drift anode layer plasma acceleration (ALPA sources) were built and tested. Robust, “all iron” design and water cooling permeate an unlimited operation with oxygen and with other high reactive gases. Long time operation of discharges in oxygen, nitrogen, argon, water vapor, propane, acetone, ethyl alcohol vapors, and in different gas cocktails has been tested. Beam parameters, generated in discharges with a voltage of Vd=0.3 to 3 kV will be presented. A simple design, only one simple power supply, and the operation without special electron source are advantages of discussed ALPA sources very suitable for many applications.

Electroporation microchips for in vitro gene transfection

A detailed study of a novel electroporation (EP) microchip forin vitro gene transfection has been conducted. Electroporation is atechnique with which DNA molecules can be delivered into cells in achamber using high electric field pulses. Compared to a commercialelectroporator, the EP microchip can attain the necessary electric fieldfor the electroporation process but takes advantage of a much lower requiredvoltage. The EP microchip overcomes the potential risk of using a highvoltage, which is the drawback of current electroporation technology.Furthermore, the advantages of this EP microchip are the use of a very smallamount of cells and genes, a very low applied voltage, a simple powersupply and a much simpler cell preparation process. Any of theseadvantages are better than, or cannot be found in, a commercial electroporator.The EP microchip, consisting of a defined cell culture cavity region withthin-film electrodes made of titanium and gold, was fabricated on a glassslide using microfabrication technologies, which include evaporation,photolithography and wet-etching methods. Two different cell lines, Huh-7and 293T, were used to demonstrate the transfection. The experimentalresults show that the EP microchip can successfully deliver greenfluorescent protein genes into both cell lines. This work demonstratesthat this EP microchip can provide in vitro gene transfection with avery small amount of cells and plasmids, requiring a much lower appliedvoltage and a simpler process than current commercial equipment. This EPmicrochip will have many useful applications in genetherapy.

An inexpensive, portable meter for measuring soil moisture

Until now, dielectric‐based soil moisture measurements required expensive cable testers or commercial systems to read probes. Here we describe a method of constructing an inexpensive meter from a multimeter and a simple power supply. When coupled with a Campbell Scientific (Logan, UT) CS615 probe, the entire system costs ≈$350 US. A single meter can be used to measure multiple probes and the entire system is quite small and portable. The new system reads soil moisture probes capable of measuring a soil's dieclectric constant. Measurements taken with the meter described here and a CR10 data logger recommended by the probe manufacturer did not differ significantly. Nor was there any measurement offset between the data logger and the meter.

Simplified power supply for long pulse CO 2 laser using zero cross switching technique

We propose a simple power supply for a longitudinally pulsed CO 2 laser with long pulse duration by the switching control of AC line ( 60 Hz ) on HV leakage transformer primary, which can generate long pulse of about 3 ms compared to a typical pulsed power supply. In this power supply, a low voltage open loop control for high voltage discharge circuit is employed to avoid the HV sampling or switching, and AC line voltage switched directly by a SCR is applied to the leakage transformer primary. Thus, there is no need of a rectified bridge and an energy-storage capacitor in the discharge circuit, and the leakage transformer allows one to omit a current-limiting resistor. In order to control the laser output power, the pulse repetition rate is adjusted up to 60 Hz . A ZCS circuit and a PIC one-chip microprocessor are used to control the gate signal of SCR precisely.

Characteristics and design of metal vacuum arc plasma source power supply for pulsed-mode plasma immersion ion implantation

Metal vacuum arc plasma sources enhance the capability of plasma immersion ion implantation (PIII) by providing a convenient and efficient means by which to introduce metallic ions into the plasma for metallic ion implantation and/or thin film deposition. The power supply of a metal vacuum arc plasma source is usually based on the artificial transformation line design, but it has several drawbacks. For instance, the pulse width cannot be adjusted conveniently and the pulsing frequency cannot exceed a predefined value. These restrictions make process optimization and synchronization with the sample high voltage modulator complicated in pulsed-mode PIII operation. In this work, we experimentally investigate the voltage–current characteristics of our metal vacuum arc plasma source. Our results suggest two different power supply designs. By adopting the design incorporating a gradual voltage–current decline, we successfully construct a simple and reliable power supply that works in a stable manner for a prolonged period of time.

A simple power supply and control unit for pulsed operation of a microchannel plate imaging detector

A simple power supply and control electronic system to operate microchannel plate (MCP) detectors for imaging transient events such as X-ray emission from laser-produced plasmas is described. The power supply consists of two parts, viz. a high voltage pulse generator of 1 kV amplitude with a variable pulse duration of 100 µs to 1 ms for the MCP input, and a regulated 5 kV d.c. for biasing the phosphor screen. The control unit synchronizes the high voltage pulse with the event and operates a safety switch to guard the detector against any accidental rise in the background pressure. A signal-to-noise ratio ≥ 75 is obtained, limited by the noise contribution of the Charge Coupled Device (CCD)-frame grabber combination attached to the MCP. The system is compact, has provision for both positive and negative pulses, is extendable to higher voltages for operating two-stage MCP, and is immune to electromagnetic interference.

Glow discharge in low-pressure excilamps

This paper presents a review of the principal publications devoted to the study of the spontaneous radiation sources operating in the uv region and discusses the properties of a low-pressure glow discharge in binary mixtures of inert gases with halides. It has been demonstrated that for variation of the excitation parameters over a wide range more than 10% emission efficiencies are realized for exciplex molecules and thatXeCl* andKrCl* molecules are formed in the main by the harpoon reaction. The current-voltage characteristics of glow discharges in cylindrical, coaxial, and planar excilamps and the parameters of the radiation ofXeCl*,KrCl*, andXeF* molecules generated on excitation of inert-gas-halide mixtures by normal and high-voltage glow discharges are presented. It is pointed out that low-pressure glow-discharge excilamps enable one to use simple power supplies.

Nonlinear Resonance in Basin Portraits of Two Coupled Swings Under Periodic Forcing

A model of a simple electric power supply network involving two generators connected by a transmission network to a bus is studied by numerical simulation. In this model, the bus is supposed to maintain a voltage of fixed amplitude, but with a small periodic fluctuation in the phase angle. In such a case, traditional analysis using direct methods is not applicable. The frequency of the periodic fluctuation is varied over a range of values near a nonlinear resonance of the two-generator network. When the bus fluctuation frequency is away from resonance, the system has several attractors; one is a small-amplitude periodic oscillation corresponding to synchronized, quasi-normal operation (slightly swinging), while others are large amplitude periodic oscillations which, if realized, would correspond to one or both generators operating in a desynchronized steady state. When the bus fluctuation frequency approaches resonance, a new periodic attractor with large amplitude oscillations appears. Although it does correspond to a synchronized steady state, this attractor has a disastrously large amplitude of oscillation, and represents an unacceptable condition for the network. Basin portraits show that this resonant attractor erodes large, complicated regions of the basin of the safe operating condition. Under conditions of small periodic fluctuation in bus voltage, this basin erosion would not be detected by traditional analysis using direct methods. Further understanding of such complicated basin structures will be essential to correctly predict the stability of electric power supply systems.

Plasma Reforming of Methane

Thermal plasma technology can be used in the production of hydrogen and hydrogen-rich gases from a variety of fuels. This paper describes experiments and calculations of high-temperature conversion of methane using homogeneous and heterogeneous processes. The thermal plasma is a highly energetic state of matter that is characterized by extremely high temperatures (several thousand degrees Celsius) and high degree of ionization. The high temperatures accelerate the reactions involved in the reforming process. Plasma reformers can be operated with a broad range of fuels, are very compact and are very light (because of high power density), have fast response time (fraction of a second), can be manufactured with minimal cost (they use simple metallic or carbon electrodes and simple power supplies), and have high conversion efficiencies. Hydrogen-rich gas (50−75% H2, with 25−50% CO for steam reforming) can be efficiently made in compact plasma reformers. Experiments have been carried out in a small device (2−3...

A high current, battery-operated power supply with power control through an on–off fast switch

A simple high current power supply is described. It can be assembled from readily available and relatively cheap components which can be itemized as follows: (1) commercial batteries; (2) fast high current switch; (3) feedback sensor; (4) PC with peripherals for controlling the switch. The apparatus was assembled for heating at very high heating rate with a low resistant load such as a graphite or vitreous carbon tube used as an atomizer in electrothermal atomization-atomic absorption spectroscopy measurements. The high heating rate must, however, be combined with a fairly good control of the temperature of the tube at various levels. This was obtained with a PC and relative peripherals which, directly or through a feedback circuit, control the switch. The system can be easily modified and adapted for other kinds of measurements as long as the high noise of the switching does not interfere with signal recovery. With the atomic spectrometer used (Perkin–Elmer Model 1100B), however, no worsening of the signal noise was observed. The level of current that can be used is mainly determined by the switch since, within a certain range, the voltage and the internal resistance of the power supply can be changed by the type of batteries and the way they are connected.