弱电流测试仪的研制

介绍了最近研制的弱电流测试仪,它的原理和设计要点。该仪器是一 便携式弱电流测试仪,可以测量10^-10-10^-4A范围的弱小电流。该仪器具有测量精度高、工作稳定、结构简单、便携等优点。     

n-γ电离室输出电流测量中I-F变换器的设计

介绍了一种用在辐射剂量仪中,对极微弱的电流信号进行放大测量的电路,并对其实现方案及各部分的特殊要求进行了详细的讨论。     

一种弱电流放大器

一、组成 高压电离室的灵敏度高、稳定性好,多用于测量环境辐射。由于它的输出信号较小(一般为10~(-15)—10~(-12)A),必须配用专门的测量仪器。本文介绍一种结构简单、灵敏度稳定的电流放大器,图1为其方框图。 电流放大器和量程转换开关装在一个φ80×111mm的铝合金圆柱外壳内,前端通过连接器与高压电离室相接,另一端是放大器的面板,装有控制旋纽和电缆插座。 放大器的输入端装有一个保护装置,当电流放大器拆离高压电离室时,能自动短路输入级MOS场效应管的栅极,     

基于电流频率变换法的微弱电流测量电路

电离辐射探测中经常需要开展微弱电离电流测量.微弱电离电流的测量因待测信号极其微弱需要克服各类型干扰源的影响,同时需要达到较宽的测量范围,故具有较大挑战.为了完成辐射防护用电离室输出微弱电流信号的测量,设计了一款基于电流频率变换法的宽量程微弱电离电流测量电路,其有效量程为10?13～10?8 A.通过Keithley 6...     

微弱电流的测量与I/F变换电路的设计

介绍了反馈式电流放大器型I／V转换和V／F变换电路的设计,详细讨论了减少噪声干扰的措施。可以测量10^-11～10^-6A的弱电流。     

用于核子皮带秤的弱电流放大器和输出电路

研制了弱电流放大器和输出电路，其最大非线性误差为±０．０６％。实验证明其性能稳定可靠，可应用于核工业仪表。     

用于核子皮带秤的弱电流放大器崐和输出电路

研制了弱电流放大器和输出电路,其最大非线性误差为±０．０６％。实验证明其性能稳定可靠,可应用于核工业仪表。     

激光功率计的变换与显示电路

介绍了激光功率计的变换与显示电路,该电路的主要功能是直接指示激光功率的大小,该电路把由激光功率计输出的模拟电压量变为数字脉冲输出,并且把输出脉冲的频率实时显示出来。本电路具有精度高、线性好、工作稳定的特点。     

多路开关式模—数变换电路

本文描述了基于高能物理实验需要研制的一种多路开关式快速模-数变换电路的设计考虑及其电路功能,较为详细地介绍了电路的工作原理,最后给出了实验结果与典型应用。     

提高微弱电流放大器性能的方法

本文从元器件的选择、电路设计、工艺设计等方面详细讨论了提高微弱电流放大器性能的方法,并在实际应用中取得良好效果.     

高性能微电流集成放大器的设计

介绍了用ICL7650运算放大器设计高性能微电流集成放大器的方法,阐述了电路的工作原理和提高放大器性能的措施,给出了实际应用的实验结果。该放大器测量范围10^-9～10^-12A,自换量程,自动校零,测量准确,工作稳定。     

Design of weak current measurement system and research on temperature impact

A dedicated weak current measurement system was designed to measure the weak currents generated by the neutron ioniza-tion chamber.This system incorporates a second-order low-pass filter circuit and the Kalman filtering algorithm to effectively filter out noise and minimize interference in the measurement results.Testing conducted under normal temperature condi-tions has demonstrated the system's high precision performance.However,it was observed that temperature variations can affect the measurement performance.Data were collected across temperatures ranging from-20 to 70 ℃,and a temperature correction model was established through linear regression fitting to address this issue.The feasibility of the temperature correction model was confirmed at temperatures of-5 and 40 ℃,where relative errors remained below 0.1％after applying the temperature correction.The research indicates that the designed measurement system exhibits excellent temperature adaptability and high precision,making it particularly suitable for measuring weak currents.     

Effects of electron radiation on commercial power MOSFET with buck converter application

Microelectronic power converters such as buck and boost converter are required to be tolerant to radiations including electron radiation. This paper examines electron radiation effects on the Ⅰ-Ⅴ characteristics of VDMOSFET and its corresponding effects in buck converter. Analysis of the electrical characteristics shows that after irradiation the threshold voltage and drain current for all VDMOSFETs degraded more than two orders of magnitude. The impact of this electrical degradation has been investigated in an application of typical buck converter circuit. The buck converter with n-channel switching transistor shows that after irradiation its output voltage increased with the drain current in the n-channel ZVN4424 A VDMOSFET, while the buck converter with p-channel switching transistor shows its output voltage decreased with the drain current in the p-channel ZVP4424 A VDMOSFET after irradiation.     

Effects of electron radiation on commercial power MOSFET with buck converter application

Microelectronic power converters such as buck and boost converter are required to be tolerant to radiations including electron radiation.This paper examines electron radiation effects on the Ⅰ-V characteristics of VDMOSFET and its corresponding effects in buck converter.Analysis of the electrical characteristics shows that after irradiation the threshold voltage and drain current for all VDMOSFETs degraded more than two orders of magnitude.The impact of this electrical degradation has been investigated in an application of typical buck converter circuit.The buck converter with n-channel switching transistor shows that after irradiation its output voltage increased with the drain current in the n-channel ZVN4424A VDMOSFET,while the buck converter with p-channel switching transistor shows its output voltage decreased with the drain current in the p-channel ZVP4424A VDMOSFET after irradiation.     

HERA-B蜂窝径迹室的张力和漏电流测量

介绍了与德国DESY合作进行的HERA－B探测器外径迹室制作过程中所使用的质量控制方法及设备,主要目的是监测并控制阳极丝与阴极之间的高压漏电流和丝的机械张力,以保证径迹室探测器的物理性能。     

pA微电流仪表的标定方法研究

为了对p A微电流测量仪表进行标定,根据微电流的测量原理,研制了一种采用高值电阻器的p A微电流源。分析了电阻器热噪声的影响,指出采用高值电阻器的必要性。分析了测量仪表的输入端口特性,指出端口电势是制约微电流源准确度的关键因素,从而确定了源电压和输出电阻器的设计参数。测试验证表明:所设计的±1~±200 p A微电流源准确度优于±3%,可满足p A微电流测量仪表的标定需要。     

一种X射线变像管能谱响应特性研究

建立了X射线变像管能谱响应特性的理论模型,介绍了一种测量能谱响应的实验方法,得到了理论结果和实验结果,实验值和理论值基本吻合。还分析了理论值和实验值之间的误差来源。