High voltage pulser with a fast fall-time for plasma immersion ion implantation

A novel high voltage (HV) modulator that offers a short fall time to minimize sputtering effects and allow more precise control of the incident ion fluence in plasma immersion ion implantation is described. The use of 36 insulated-gate bipolar transistors in the 30 kV hard-tube pulser reduces the HV fall time to 3.5 μs, compared to a fall time of 80 μs if a pull-down resister is used. The voltage balance is achieved by a voltage-balancing resistor, clamped capacitance, and the synchronization of drive signals. Compared to the traditional method employing a pull-down resister or an additional hard tube, our design consumes less power and is more economical and reliable.     

A high voltage pulse power supply for metal plasma immersion ion implantation and deposition

We describe the design and implementation of a high voltage pulse power supply (pulser) that supports the operation of a repetitively pulsed filtered vacuum arc plasma deposition facility in plasma immersion ion implantation and deposition (Mepiiid) mode. Negative pulses (micropulses) of up to 20 kV in magnitude and 20 A peak current are provided in gated pulse packets (macropulses) over a broad range of possible pulse width and duty cycle. Application of the system consisting of filtered vacuum arc and high voltage pulser is demonstrated by forming diamond-like carbon (DLC) thin films with and without substrate bias provided by the pulser. Significantly enhanced film∕substrate adhesion is observed when the pulser is used to induce interface mixing between the DLC film and the underlying Si substrate.     

Nanosecond electro-optical switching with a repetition rate above 20 MHz

We describe an electro-optical switch based on a commercial electro-optic modulator (modified for high-speed operation) and a 340 V pulser having a rise time of 2.2 ns (at 250 V). It can produce arbitrary pulse patterns with an average repetition rate beyond 20 MHz. It uses a grounded-grid triode driven by transmitting power transistors. We discuss variations that enable analog operation, use the step-recovery effect in bipolar transistors, or offer other combinations of output voltage, size, and cost.     

A low-frequency high-power arbitrary-shape voltage pulse generator

A circuit diagram and design of the arbitrary-shape bipolar voltage pulse generator with amplitudes up to 800 V and a peak output on a matched load of 400 kW are described. The generator is based on car rechargeable batteries and power insulated-gate bipolar transistors (IGBTs). Results of the experiments aimed at producing high-power harmonic signals with frequencies of 50 Hz and 1 kHz are presented.     

一种开关型高压直流电源的设计

提出一种脉宽调压式功率管－ＬＣ高压直流电源的电路设计。由脉宽调制［ＰＷＭ］电路输出方波脉冲驱动开关功率管－ＬＣ电路,使其产生高频功率振荡;通过调谐脉冲宽度控制输出高压;设计同步脉冲反馈电路,迫使驱动电路的脉冲频率与ＬＣ谐振同步,从而提高输出效率和脉宽调谐能力,实现大功率输出。     

A generator with a voltage inversion and output pulse amplitude doubling

A generator with a voltage inversion across storage capacitors and output pulse amplitude doubling at the load without increasing the number of stages and raising the supply voltage is described. IGBT transistors are used as switches. The special feature of the circuit design of the generator is the replacement of charging resistors by charging diodes and connection of the supply voltage through an inductor. Functional and experimental diagrams and measurement results are given.     

A Marx generator with a doubled output voltage

A generator of high-voltage pulses with doubling of the output voltage built according to the Marx scheme on the basis of ten stages connected in series is described. IGBT transistors are used as switches in the circuit. A specific feature of the generator circuit design is the substitution of charging diodes for charging resistors and connection of the supplying voltage through an inductor. This made it possible to double the amplitude of pulses across a load, which is proportional to the number of connected stages, and minimize the power loss during charging of storage capacitors. In an experiment performed at a supply voltage of 500 V, a pulse voltage of 7.4 kV was obtained across a load of 400 Ω.     

离子风空气加速器的电源设计

针对电压微小波动对离子风空气加速器负载放电特性影响的问题,设计了一款特殊的高压电源.电源的硬件电路设计包括主控制电路、功率场效应管(MOSFET)的驱动和保护电路、采样反馈电路、高压升压电路和多倍压整流电路;软件设计包括主控芯片PIC的系统配置、脉宽调制(PWM)占空比及频率设定、主程序及中断子程序流程图.最后,通过M...     

A New Two-Quadrant Squarer/Divider Circuit for true RMS-to-DC converters in MOS technology

In this paper, a new log-domain two-quadrant squarer/divider circuit for current mode RMS-to-DC converters is presented. The proposed circuit has been realized using MOSFET transistors that are operating in weak inverted saturation region. It features very low supply voltage (1 V), low power consumption (<3 μW), two-quadrant input current, wide input dynamic range, immune from body effect and low circuit complexity. Simulation results by HSPICE show high performance of the circuit and confirm the validity of the proposed design technique.     

Bipolar high-repetition-rate high-voltage nanosecond pulser

The pulser designed is mainly used for producing corona plasma in waste water treatment system. Also its application in study of dielectric electrical properties will be discussed. The pulser consists of a variable dc power source for high-voltage supply, two graded capacitors for energy storage, and the rotating spark gap switch. The key part is the multielectrode rotating spark gap switch (MER-SGS), which can ensure wider range modulation of pulse repetition rate, longer pulse width, shorter pulse rise time, remarkable electrical field distortion, and greatly favors recovery of the gap insulation strength, insulation design, the life of the switch, etc. The voltage of the output pulses switched by the MER-SGS is in the order of 3-50 kV with pulse rise time of less than 10 ns and pulse repetition rate of 1-3 kHz. An energy of 1.25-125 J per pulse and an average power of up to 10-50 kW are attainable. The highest pulse repetition rate is determined by the driver motor revolution and the electrode number of MER-SGS. Even higher voltage and energy can be switched by adjusting the gas pressure or employing N(2) as the insulation gas or enlarging the size of MER-SGS to guarantee enough insulation level.     

A high voltage pulsed power supply for capillary discharge waveguide applications

We present an all solid-state, high voltage pulsed power supply for inducing stable plasma formation (density ～10(18) cm(-3)) in gas-filled capillary discharge waveguides. The pulser (pulse duration of 1 μs) is based on transistor switching and wound transmission line transformer technology. For a capillary of length 40 mm and diameter 265 μm and gas backing pressure of 100 mbar, a fast voltage pulse risetime of 95 ns initiates breakdown at 13 kV along the capillary. A peak current of ～280 A indicates near complete ionization, and the r.m.s. temporal jitter in the current pulse is only 4 ns. Temporally stable plasma formation is crucial for deploying capillary waveguides as plasma channels in laser-plasma interaction experiments, such as the laser wakefield accelerator.     

MIC29750用于大功率半导体激光器的驱动

MIC29750是一种大功率低压差线性稳压电源芯片,最大压差0.35V,输出电流可达7.5A.本文介绍的大功率激光器驱动电源采用“电压源＋MOSFET”结构,以MIC29750芯片作为大功率低纹波电压源,并具有限流保护、上电保护等功能,可供大功率半导体激光器的驱动、控制等应用领域借鉴,是一种高性能、低成本的解决方案.     

High voltage pulse shaping of e-beam diode using perveance variation

This paper presents a new high voltage pulse shaping methodology for pulsed power applications. The aim is to generate high voltage square pulse across anode cathode gap of e-beam diodes. The non-linear time varying perveance characteristics of e-beam diodes are used for shaping of output voltage pulse across it, generated directly from Marx generator. Analytically, it has been shown in the paper that under certain conditions, if achieved, Marx generator feeding an e-beam diode can produce a square-like pulse at the output, without any extra pulse shaping arrangements. Experimental results to support the analysis are also presented in the paper.     

基于光敏耦合定时器的压频转换器的实现

研制了基于定时器的压频转换器, 电路主要由工作于非稳态多谐振荡器模式下的定时器LM555和两个光敏电阻构成. 由于数字存储振荡器测得的定时器输出波频率与所施加的输入电压基本呈线性比例关系, 所研制的转换器为类数字输出, 因此具有线性输入/输出关系、 体积小、 易携带和高性价比等优点. 此外, 定时器输出波可以直接与PC机、 微处理器或微控制器相连, 不需要模/数转换器就能完成对输入电压信号的进一步处理.     

A microcontroller-based variable voltage variable frequency sinusoidal power source with a novel PWM generation strategy

The present paper describes the development of a low cost, microcontroller-based variable voltage variable frequency sinusoidal power source, which is the demand of the day for various applications. The power source is developed using MOSFET H-bridge inverter and with a stand alone LCD display system. The design methodology proposes to utilize a novel concept of generating sinusoidal pulse width modulation signals for the driver circuit of the inverter. The system proposes to incorporate a ROM-based LUT within the power source itself for the sinusoidal signal generation with enhanced stability. This low cost, yet accurate power source has been successfully developed for wide range of voltage commands (30-80 V rms) and frequency commands (40-70 Hz), and their real-life performances in voltage wave generation were also found to be quite satisfactory.     

An inductive voltage divider

A small-sized inductive nanosecond pulse-voltage divider of simple design is described. The divider is used for measuring the voltage at the output unit of the Angara-5-1 facility.     

Low-noise amplification of voltage and current fluctuations arising in epithelia

Two low-noise differential input amplifiers designed for voltage and current fluctuation measurements in epithelia are described. The first one uses a matched pair of low-noise transistors and is particularly suited for low-frequency current and voltage noise measurements in frog skin and other preparations with impedances below 1 kOmega. The second one is designed around a matched pair of JFETs and can also be used for higher source impedance. Performance is demonstrated with Na(+) current power density spectra obtained from frog skin with the transistor-input stage.     

A compact high-voltage nanosecond marx generator based on air-field dischargers

Results of the development and study of a 14-stage air high-voltage pulse generator with an output voltage of up to 250 kV, a current rise time of 10 ns, and blow capacitance of 400 pF are presented. The design and the schematic circuit diagram of the generator are described.     

基于SPCE061A实现的语音数控电源

本文通过选用一教具有语音功能的单片机(SPCE061A)设计并实现了一台数控直流稳压电源.该电源的输出电压在0～ 9.9V的范围内,通过按键可以实现步进0.1V和输出电压预置,同时结合SPCE061A单片机在语音方面的优势,还可以实现电压播报和语音控制的输出电压预置.在保证数控电源基本功能的条件下,增强了系统的人性化环境.     

基于EPWM的电动机调压节能控制装置研究

目前,大多数调压控制器对电动机及负载的适应能力不强,节能装置动态响应差且不易收敛,调压精度不够,不能快速、有效、准确地提供电动机定子端电压值。该文阐述了基于EPWM的电动机调压节能控制装置的工作原理,该装置是一种无级调节的、控制简单、体积小、成本低、适用于各种不同功率的实用性强的高精度电压跟踪控制装置,主要功能就是快速、有效、准确地跟踪基准值,提供定子端最优电压值。从保证调压节能控制装置能够稳定输出定子电压值的角度出发,兼顾快速性、稳定性和准确性,提出一种更好的控制方法,把电力电子中的整流、逆变技术应用到控制装置中,研究了一种无级调节的电动机调压节能控制装置。