JDIC型转差离合器调速装置的改装

该装置原来是通过改变晶闸管导通角实行转速控制的，现改为电压控制型开关元件ＶＭＯＳ管，利用脉宽调制来控制ＶＭＯＳ管的导通和截止。整套装置线路简单，元器件少，且调试维修方便。     

提高小信号转换精度的CMOS全波整流电路

本文提出一种能改善小信号转换精度的ＣＭＯＳ全波整流电路。该电路通过对执行电压－电流转换任务的Ｐ－ＭＯＳ和Ｎ－ＭＯＳ晶体管施加偏置电压,且偏压数值近似等于各管的阈电压ＶＴＰ和ＶＴＮ,从而克服了ＣＭＯＳ整流中＂死区＂较大和阈电压失配造成的影响。模拟电路的测量结果表明,该电路对０．１ｍＶ级的输入信号也有线性度极好的转换特性。     

功率VDMOSFET的瞬态热阻抗测量

介绍了利用ＶＤＭＯＳＦＥＴ的寄生ｐｎ结二极管Ｄｓｄ作为温敏元件来测量功率ＶＤＭＯＳ管热阻抗的方法，给出了温敏参数中温度系数和几类功率ＶＤＭＯＳ管瞬态热阻抗的测量结果，讨论了对热阻抗测量准确度有较大影响的四个因素，其结果，在一定条件下进行的瞬态热阻抗测量可用来监测ＶＤＭＯＳ管的芯片粘接质量和用作功率ＶＤＭＯＳ管的快速热筛选。     

MOS控制晶闸管（MCT）的设计

讨论了ＭＣＴ的结构设计及耐压设计。通过对结构参数的最佳化选择，制造出开关电流９Ａ，耐压９００Ｖ的ＭＣＴ芯片。ｎ沟ＭＯＳ阈值电压为２Ｖ，ｐ沟ＭＯＳ阈值电压为－５Ｖ。当门极加－７Ｖ电压时，其关断电流密度为２２０Ａ／ｃｍ＾２。     

无刷直流电动机控制电路栅极电源的获得方式

无刷直流电动机控制电路栅极电源的获得方式钟仁人（西安徽电机研究所７１００７７）１无刷直流电动机桥路中ＶＭＯＳ（或ＩＧＢＴ）的栅极电源无刷直流电动机广泛采用桥式电路，而ＶＭＯＳ管或ＩＧＢＴ是其主要应用的功率器件。图１绘出了ＶＭＯＳ管的三相桥路（绕组星形...     

配电系统自动化及其发展（五）──配电图资系统AM／FM／GIS

配电系统自动化及其发展（五）──配电图资系统ＡＭ／ＦＭ／ＧＩＳ刘广一，王明俊，于尔铿电力部电力科学研究院，１０００８５北京清河ＤＩＳＴＲＩＢＵＴＩＯＮＡＵＴＯＭＡＴＩＯＮＡＮＤＩＴＳＤＥＶＥＬＯＰＭＥＮＴ（Ｖ）──ＡＵＴＯＭＡＴＥＤＭＡＰＰＩＮＧ／Ｆ...     

使用DOS命令实现特定文件的跨目录搜寻

使用ＤＯＳ命令实现特定文件的跨目录搜寻贵州风华机器厂李德文针对《方便实用的文件搜寻工具》一文，对ＭＳＤＯＳ３．３０和ＭＳ—ＤＯＳ．０以上两类版本下，特定文件的跨目录搜寻问题进行了讨论。《家用电器科技）１９９５年第６期登载了刘宇彤、李金红同志的文章《方...     

我国电网调度要向国际水平迈进──在2月9日国调电网调度自动化系统实用化验收会议上的讲话

我国电网调度要向国际水平迈进──在２月９日国调电网调度自动化系统实用化验收会议上的讲话史大桢电力工业部，１０００３１北京ＲＥＦＥＲＴＯＩＮＴＥＲＮＡＴＩＯＮＡＬＬＥＶＥＬＴＯＩＭＰＲＯＶＥＴＨＥＰＯＷＥＲＳＹＳＴＥＭＤＩＳＰＡＴＣＨＩＮＣＨＩＮＡ￥Ｓ...     

俄罗斯统一电力系统反事故自动装置的一些技术特性

俄罗斯统一电力系统反事故自动装置的一些技术特性阿布拉缅科娃Ｈ．Ａ．彼得罗夫Ａ．Ｍ．波波夫西伯利亚电网设计院，俄罗斯新西伯利亚市ＳＯＭＥＣＨＡＲＡＣＴＥＲＩＳＴＩＣＳＯＦＥＭＥＲＧＥＮＣＹＣＯＮＴＲＯＬＤＥＶＩＣＥＳＦＯＲＲＵＳＳＩＡＮＩＮＴＥＧＲＡＴ...     

电压空间矢量调制与常规SPWM的比较研究

在分析电压空间矢量调制（ＳＶＰＷＭ）基本原理的基础上,证明了ＳＶＰＷＭ具有最大的直流电压利用率。将ＳＶＰＷＭ和常规ＳＰＷＭ进行了对照和分析。提出了一种与ＳＶＰＷＭ等效的改进ＳＰＷＭ调制方法。另外,提出了一种与低开关损耗ＳＰＷＭ相对应的ＳＶＰＷＭ的实现方法,使开关损耗降低了３３％。     

新型功率放大器

简要介绍了甲类和乙类功率放大器原理,分析了其优缺点;详细论述了采用高压运算放大器、跨导技术和甲乙类推挽电路技术所设计电子线路的工作原理;设计了高稳定性、低失真度、甲乙类全互补推挽式功率放大器.     

Active rc filters using an operational transconductance amplifier and an operational amplifier

An operational transconductance amplifier (OTA) and an operational amplifier are being used to synthesize various second-order cascadable active RC filters. Two of them are active R filters. The filters are studied both theoretically and experimentally and are found to have low sensitivity to variations in their component values. They work satisfactorily in practice, except that some of them have a rather limited dynamic range.     

A 63‐dB gain OTA operating in subthreshold with 20‐nW power consumption

This paper presents a two‐stage bulk‐driven operational transconductance amplifier operating in weak‐inversion region. The proposed amplifier is upgraded using recycling structure, current shunt technique, positive feedback source degeneration and indirect frequency compensation feedback to enhance transconductance under a reasonable stability. Combining these approaches leads to an ultra‐low‐power high performance amplifier without increasing power dissipation compared to the conventional one. Simulation results in 0.13‐µm complementary metal–oxide–semiconductor technology show the proposed structure achieves a 63‐dB DC gain at 0.25‐V supply voltage with just 20‐nW power dissipation. Copyright © 2016 John Wiley & Sons, Ltd.     

SOI高温压力传感器专用集成电路设计

针对压力传感系统高温条件下无法稳定工作、性能下降等问题,设计了一种基于SOI CMOS高温工艺的压力传感器专用集成电路(ASIC),主要由零温度系数恒流源、仪表运算放大器(由恒定跨导运放组成)和零温度系数电压基准组成,具有为压力传感器供电、放大输出信号及调节零点的功能,重点介绍了零温度系数恒流源、仪表运放及组成仪表运放的运算放大器等相关电路。仿真结果表明,-55~225℃温度范围内,恒流源温度系数为109ppm/℃,运算放大器输入MOS管跨导几乎与温度无关,仪表运放输入输出电压成正比且共模抑制比高达125 d B。测试结果显示该压力传感器专用集成电路可在225℃下正常工作。     

Class AB amplifier with enhanced slew rate and GBW

The design of a micropower class AB operational transconductance amplifier with large dynamic current to quiescent current ratio is addressed. It is based on a compact and power-efficient adaptive biasing circuit and a class AB current follower using the quasi-floating gate (QFG) technique. The amplifier has been designed and fabricated in a 0.5-μm CMOS process. Simulation and measurement results show a slew rate (SR) improvement factor versus the class A version larger than 4 for the same supply voltage and bias currents, as well as enhanced small-signal performance.     

A unified approach to teaching feedback in electronic circuitscourses

A generalized negative feedback model is proposed as a vehicle for teaching feedback amplifiers in engineering schools. The model applies to both discrete and operational amplifier configurations and does not dictate the use of specific gain definitions (such as transconductance) for analyzing a given negative feedback amplifier. The main features of the suggested methodology and examples for quick evaluation of closed-loop gain, frequency response, and input and output impedances of negative feedback amplifiers are presented. The proposed method has been successfully tested in the class room over the past two years     

Programmable feedforward linearized CMOS OTA for fully differential continuous‐time filter design

In this paper, a feedforward linearization method for programmable CMOS operational transconductance amplifier (OTA) is described. The proposed circuit technique is developed using simple source‐coupled differential pair transconductors, a feedback‐loop amplifier for self‐adjusting transcoductance (g_m) and a linear reference resistor (R). As a result, an efficient linearization of a transfer characteristic of the OTA is obtained. SPICE simulations show that for 0.35µm AMS CMOS process with a single +3V power supply, total harmonic distortion at 1 V_pp and temperature range from ?30 to +90°C is less than ?49.3 dB in comparison with ?35.8 dB without linearization. Moreover, the input voltage range of linear operation is increased. Power consumption of the linearized OTA circuit is 0.86 mW. Finally, the OTA is used to design a third‐order elliptic low‐pass filter in high‐frequency range. The cut‐off frequency of the operational transconductance amplifier‐capacitor (OTA‐C) filter is tunable in the range of 322.6 kHz–10 MHz using the feedforward linearized OTAs with the digitally programmable current mirrors. Copyright © 2009 John Wiley & Sons, Ltd.     

Analysis and implementation of a fourth‐order bandpass filter for R‐wave detection of an implantable cardiac microstimulator

This paper presents an ultra‐low‐power fourth‐order bandpass operational transconductance amplifier‐C (OTA‐C) filter for an implantable cardiac microstimulator used to detect the R‐wave of intracardiac electrograms. The OTA‐C filter fabricated by TSMC 0.35‐µm complementary metal–oxide–semiconductor (CMOS) technology is operated in the subthreshold region to save power under a supply voltage of 1 V. The current cancellation technique is adopted to reduce the transconductance of the amplifier. Through this, the low‐frequency OTA‐C filter can be realized by ultra‐low transconductance with on‐chip capacitors. Direct comparison to conventional RLC ladders replaced by OTA‐C circuits shows that the method of reducing the number of OTAs further diminishes power consumption. Design issues, including ultra‐low transconductance, linearity, and noise, are also discussed. Measurement results show that the low‐voltage, low‐power filter has a bandwidth between 10 and 50 Hz, third inter‐modulation distortion of ?40 dB, dynamic range of 43 dB, and power consumption of only 12 nW. The real electrocardiography signal is fed into the bandpass filter to verify the function of signal processing with the distribution of the R‐wave. Copyright © 2012 John Wiley & Sons, Ltd.     

An improved current-comparator-based 1000-A transconductanceamplifier for the in-situ calibration of transformer loss measuringsystems

A current comparator technique and an error feedforward control strategy are applied to the design of a high current transconductance amplifier to obtain a highly stable and accurate output current. The transconductance amplifier features a current output range of 1000 A with a compliance voltage of 3 V. It has the ability to provide a highly accurate current to a circuit that is operated at high voltage. This high-current transconductance amplifier is used in a system for the in-situ calibration of transformer loss measuring systems. The output current has accuracies of better than ±10 ppm (parts-per-million) in both magnitude and phase