一种智能型超高频电压表的实现

文中介绍了一种可同时显示被测信号电压和频率的超高频电压表的实现方法。应用单片机技术,该仪器不仅用软件完成了检波特性曲线的线性化,实现了高频电压的数字化测量,而且根据被测信号频率能自动地在线修正测量系统的频响误差,从而大大提高了仪器性能。     

示波器高频高压电源及其检修

示波器高频高压电源及其检修江苏省淮阴邮电局计量科张凤楼现代示波器多采用高频高压来供给示波管各极电压。这对高压源的结构、体积、整流效率都是有利的，同时加以自动调节，对高压的性能将进一步完善。其典型结构如下：高频振荡产生高频电压。所谓高频是对工频而言，振...     

电火花线切割机床高频电源的使用

在火花放电过程中,脉冲电压是产生电火花放电的必要条件,而高频电源就是产生脉冲电压的一个大功率高频脉冲信号源,又称脉冲电源（以下通称为高频电源）,它是数控线切割机床中的一个重要组成部件。在一定条件下,线切割机床的加工效率往往取决于高频电源的性能,因此,在使用过程中高频电源显得尤为重要。下面根据笔者的经验谈谈对高频电源的一些认识。     

高频设备上的有载调压整流变压器

目前,高频感应加热设备的整流大都采用大功率高压硅整流器取代耗能大的闸流管整流器。实践证明:高压硅整流器有明显的节能效果,能提高设备的效率。然而,使用这种高压硅整流器,设备的整流直流电压不能调节,不能满足各种零件对高频热处理的需要。在外电压较高的情况下(特别是在晚上),高频设备输出的直流电压很高,达到15千伏。这样高的电压极易损     

全桥移相式高频软开关的改进研究与应用

本文研究了现有的全桥移相式零电压PWM软开关电路,提出了把MOSFET和IGBT两种不同的功率器件分别应用在超前桥臂和滞后桥臂上,同时在变压器副边采用倍流整流电路,从而获得了一种具有高变换效率、结构简单,适用于大功率、高频场合的全桥移相式零电压零电流高频软开关电路拓扑结构。另外以UC3875 PWM控制芯片为基础设计了DC-DC高频软开关电源,验证了电路原理的正确性及实际应用的可行性。     

晶体管双失谐差动鉴频器的设计

一、概述鉴频器(或称频率检波器)是用来对调频波进行检波的,使它输出端上的电压变化重现出已调频振荡瞬时频率的变化规律。鉴频器不仅在电视和调频接收机中作检波用,而且在无线电多路通讯、锁相技术、频率测量、自动控制、自动频率微调,移频电报接收机以及仪器仪表中广泛使用。仪器仪表对鉴     

调压电磁阀高频特性的研究

调压电磁阀高频控制的目的在于减小电流、降低功耗，补偿电压和温度波动的影响。文章在建立其高频控制电路微分方程的基础上，应用Simulink进行仿真可以准确获得控制特性，根据该特性对调压电磁阀进行高频控制。通过试验，控制特性与实际相符，具有工程实际意义。     

六级杆离子传输系统射频电源控制设计

设计一种基于AB类推挽功放原理的射频线性电源,可调频率为1~6 MHz,电压≥900 V。由ARM控制器通过检波电路检测输出峰峰值构成闭环控制来稳定输出电压。通过串口设定输出频率、电压以及实时显示电压。实验测得1.420 MHz、3.086 MHz和5.347 MHz输出电压分别为2020 V、1960 V和928 V;在3.094 MHz测得电压和频率稳定性分别为0.44%和0.096%。该电源已用于质谱仪射频六级杆离子传输且运行稳定。     

基于小波变换的谐波检测法

本文介绍了采用小波变换的谐波有效值测量原理.提出了差拍选频与子带滤波相结合的谐波测量新方法,以及同步检波与子带滤波相结合的电压闪变检测及其频谱分析方法.仿真实验结果表明,文中所提出的方法适用于短时间谐波、电压闪变的检测与时频分析.     

门式起重机高频感应电的形成及其防范

针对起重机吊钩带异常电压认识的局限性,在建立高频电磁波环境下门式起重机的天线效应模型的基础上,分析了起重机高频感应电压的形成原理、现象及影响,探讨了相关高频感应电处理方法,将为工厂企业解决类似安全生产问题提供有益的借鉴。     

GIS电压互感器振动的在线检测与诊断

局部放电测量技术弥补了目前GIS设备预防性试验方法的不足,已成为运行GIS设备监测的重要手段。介绍了利用超声波、高频脉冲电流、气体分析测量技术,对中国石油化工股份有限公司广州分公司110kV GIS电压互感器进行局部放电测量,并对发现的缺陷分析处理。     

Measuring the depth of conducting coatings with gap and substrate-conductivity detuning

The problem of measuring the depth of nonmagnetic conducting coatings on nonmagnetic substrates with simultaneous detuning of the gap and substrate conductivity is considered. It is shown that the gap can be detuned by introducing a compensating voltage with a fixed phase and an amplitude that is adjusted proportionally to the high-frequency channel signal.     

Powerful Sources for High Frequency Electromagnetic Transducers for Measurement,Monitoring and Diagnostics

Conceptual provisions for the construction of miniaturized variable parameter of high-power high-frequency broadband radio pulse amplifiers have been developed: filling frequency, duration, significant peak current and peak voltage. A circuit-based solution is proposed for constructing high-frequency radio signal of high-power amplifiers, whose frequency varies in the interval 0.1 … 20 MHz, the time duration is 1 … 10 periods of pulse filling frequency, with an output current that reaches 200 A and voltage up to 4 kV. The use of the developed powerful amplifier will allow creating and improving the instruments for ultrasonic quality control of products by electromagnetic-acoustic transducers in industry and electromagnetic transducers in medical devices using the effect of nuclear magnetic resonance, electron paramagnetic resonance, and also in measuring devices.     

A method for detecting tool wear on a CNC lathe using a doppler radar detector

Installing a non-contact in-process tool wear detection system on a computer numerical control lathe can help prevent product defects and improve product quality without impacting product cycle time. Many methods have been proposed for non-contact in-process tool wear detection. In particular, a recent international patent application describes a method for measuring the torque in a rotating axle using a high-frequency wireless transmitter/receiver and a vibrating string. The method has reportedly been used to detect cutting on a manual lathe. The authors present a new method for measuring tool wear using a high-frequency wireless transmitter/receiver alone, without a vibrating string. The high-frequency transmitter/receiver apparently responds to metal-metal contact noise rather than, or more strongly than, to signals generated by a vibrating string. The findings could help bring automated tool wear monitoring systems closer to the level of performance needed for practical use in industry.     

基于Multisim10的高频调谐放大电路

针对高频调谐放大电路传统分析方法较难的问题,采用Multisim10设计和分析电路,可方便地比较仿真数据和真实数据。放大部分用参数扫描法选择合适的元件,选频部分采用了调节输出电压最大以得到调谐电容的方法;对电路输出频率、电压增益、通频带进行了仿真分析,完成了对多输入小信号的放大和选频;分析了负载和结电容Cbc对电路的影响,给出了提高品质因数和解决稳定性的方法。研究结果表明该设计方法合理,性能指标达到设计要求。     

A differential high-voltage divider

The design, main design formulas, and test results of a small-size differential high-voltage divider are presented. The conditions determining correctness of using the divider for measuring nanosecond high-voltage signals are obtained. It is shown that the differential voltage divider has some limitations in low- and high-frequency regions. Experiments have been performed on a TэY-500 pulsed electron accelerator with the following characteristics: the accelerating voltage is 350–450 kV, the base pulse duration is 100 ns, the rise time is <5 ns, and the complete pulse electron energy is up to 250 J. The pulse repetition rate is 1–3 pulses/s. To restore the shape of the measured voltage, it is necessary that the output signal from the voltage divider be integrated. The measurement error does not exceed ±10%.     

Signal Processing Circuit Design of Infrared Detection System with SO2 Concentration Based on Correlation Filter Technology

Signals from infrared detector are very weak in SO2 concentration measuring system.In order to improve the sensitivity of detection,combining with filter correlation technology and infrared absorption principle,the weak signal processing circuit is designed according to correlation detection technology.Under laboratory conditions,system performance of SO2 concentration is tested,and the experimental data are analyzed and processed.Then relationship of SO2 concentration and the measuring voltage is provided to prove that the design improves measuring sensitivity of the system.     

基于电容分压法的配网线路智能电压传感器

配网线路电压的准确测量是配网故障检测和诊断的前提。根据导线对地的分布电容及传感器与导线之间的分布电容,构建了输电线路电压测量模型,分析了测量电容、杂散电容、导线对地电容的变化对测量结果的影响,提出了测量电容的选取原则;结合现场应用情况,分析了配网线路敷设高度、环境温湿度和安装点到杆塔距离等因素对测量结果的影响,提出了智能电压传感器的设计及安装原则。最后通过模拟实验和现场试验验证了测量模型的正确性及各影响因素对传感器测量结果的影响。其有望在配网电压测量领域大面积应用。     

小型风力发电系统正弦波逆变器的设计与实现

针对小型风力发电系统设计了一种基于高频升压逆变电路的正弦波逆变器,与推挽逆变电路和全桥逆变电路相比,省掉了工频变压器,实现高功率密度逆变,减小了体积,减轻了重量,降低了成本。逆变主电路采用正弦波控制方式,可降低谐波,提高功率因数。控制电路以微处理器PIC16F877A为核心,在此基础上设计出一台2 kW实验样机,实验结果表明该逆变器具有较高的效率,输入直流电压范围宽,输出电压失真度较低。     

电梯导轨垂直度检测机器人机构设计

针对传统电梯导轨垂直度检测方法误差大、检测器件分离、不利于一体化检测等不足,用一种全新的检测方法,设计了一款基于倾角检测的电梯导轨垂直度检测机器人。文中分析了新方法的检测原理,详细介绍了检测机器人的机构设计方案。经过验证,该检测方法效率高、检测精确,具有很好的实用价值。