基于恒流充放电测量的锂离子电池内阻估计

针对准确测量锂离子电池内阻的需求,提出一种基于恒流充放电测量的内阻估计方法。该方法通过分析电路模型的串并联结构特性,采用方波恒流源激励锂电池获得充放电输出响应,利用充放电状态切换产生的电压跳变估计欧姆内阻,再通过差分和对数变换,将阻容回路参数估计问题建模为直线拟合问题,降低问题求解的难度。通过软件仿真和实测数据分析验证该方法的有效性,与现有测量方法相比,该方法能有效消除单频点测量引起的不同相问题,具有测量准确、简单可靠的优点,在实际测量中获得较好的使用效果。     

用锁相放大器实现电池内阻在线测量

本文对传统的电池内阻测量方法进行了研究比较,提出了用锁相放大器测量电池内阻的新方法,详细阐述了锁相放大器的基本结构与工作原理以及用锁相放大器实现电池内阻测量的实际电路,通过对多种电池内阻的测量以及电池充放电过程中内阻的在线监测,有效地克服了噪声和干扰,快速获得稳定、精确的内阻测量数据,能实现完全的在线检测,并且简化了设计。     

基于交流测量法的蓄电池内阻测量装置的研究

对传统的几种蓄电池单体电池内阻测量方法如密度法、开路电压法和直流放电法进行了比较分析 ,指出了它们的优缺点。提出了一种新的蓄电池单体电池内阻测量装置 ,该装置以MC6 8332单片机为控制核心 ,采用交流测量法 ,实现了蓄电池单体电池内阻的在线测量。着重介绍了该装置的工作原理以及硬件与软件设计     

两种测量电压有效值方法的比较

为准确测量不同频率的交变电压有效值,介绍两种常用的测量方法——热等效法和公式计算法,并分析各自的特点。分别利用这两种方法搭建测量电路,对不同频率正弦波有效值进行测量。对测量数据进行分析,客观比较两测量电路的精度和频率响应。分析结果表明:热等效法适合测量高频信号的电压有效值,而公式计算法适合测量低频信号的有效值,该结论为不同场合测量有效值的各种应用做出参考。     

基于锁相放大的超级电容内阻检测装置研究

超级电容模块组在使用时存在电压均衡问题,为保证其在使用的过程中的可靠性,安全性、延长超级电容的使用寿命,需对超级电容内阻进行检测。首先阐述了锁相放大的超级电容内阻测量原理,在此基础上设计了一种基于锁相放大的超级电容内阻测量电路,包括交流信号源电路、信号调理电路、锁相放大电路、低通滤波电路等。实验结果表明,超级电容内阻检测系统能有效地检测超级电容的内阻,其检测结果的重复性误差小于3%,达到了超级电容内阻检测的要求。     

反激变换器输出纹波电压分析与测量

针对反激变换器输出纹波电压比较大的缺点,分别分析了连续电流模式(CCM)、断续电流模式(DCM)的能量传输过程,并通过能量传输过程中反激变压器次级线圈电流和输出电容电压之间的关系,从根本上得出了反激变换器纹波产生的机理;对于纹波测量,总结出了三种正确的测量方法,并介绍了各种测量法的相关测量装置及相应注意事项,简述了EIAJ-RC9002A测量标准。实验测量表明,采用同轴电缆法测量纹波电压正确可行。     

低压差线性电压调整器电源纹波抑制比测试方法

低压差线性电压调整器应用广泛,电源纹波抑制比是反映其性能指标的关键参数之一。为解决传统电源纹波抑制比测试方法测量频率范围较小、测试效率低、难以满足高电源纹波抑制比测试等不足,提出基于功率分配器和低频网络分析仪相结合的电源纹波抑制比测试方法,并采用典型低压差线性电压调整器对基于功率分配器和基于电感电容总和节点法的两种测试方法进行测试验证。实验结果表明:基于功率分配器的电源纹波抑制比测试方法最低测试频率可达30 Hz,可满足70 d B以上电源纹波抑制比的测试需求,具有频率测量范围更宽、测试效率高等特点。     

一种实用蓄电池内阻测试仪的研制

针对目前国内蓄电池内阻测量方法复杂的问题,研制了一种新型蓄电池内阻测试仪。该测试仪基于鉴相处理技术,采用高精度ADC提高了测试精度,大大简化了测量程序。介绍了该测量方法的原理和具体实现过程。实际情况表明:该方法简单、精度高,具有良好的实用价值和推广意义。     

一种专用高速ECL移位寄存器电路的设计和测量

介绍了由先进的多晶硅发射极NPN晶体管和高速ECL100E141电路单元构成的一块专用高速移位寄存器阵列的设计和主要参数的测量.提出一种移位寄存器最高工作频率的测量方法.该方法有效地消除由外部连线和外接器件及测试夹具所造成的寄生延迟对测试结果的影响,准确地测试出电路的最高工作频率.本电路并行输入输出和移位的最高工作频率为410MHz.该电路是为提高某些测试系统高频测量性能而设计的全功能移位寄存器阵列.其布局和结构合理灵活,可以方便地构成多种数据移位寄存方式,有利于使用和测量,具有一定的通用性.     

电子仪器仪表常用检修法

电子仪器仪表常用检修法北京舫空材料研究所王焕盛参数测量法通过测量电路的直流电平，电流、电压，某点对地的电阻、电压以各元件参数，来寻找和判断故障所在的范围。波形观察法常用来检查稳压源、脉冲电路、振荡器的波形、幅度、频率及干扰等。稳压源的纹波电压可采用高...     

Residual Capacity Estimation for Lead–Acid Batteries Used in Automobiles by the Method of Median Internal Resistance

The purpose of this study was to investigate the method of residual capacity estimation for lead–acid batteries used in automobiles. First, relation charts for the internal resistances of a battery at various load currents to residual capacity percentages were established, and the relation charts for all load currents were then combined to obtain the corresponding residual capacity by calculating medians. The experimental equipment included lead–acid batteries for automobiles, an electronic loader, an internal resistance tester, and test cables. The experimental procedures were discharging the battery with the electronic loader, using the internal resistance tester to record the internal resistance, voltage, and temperature of the battery, and then transmitting the data to a computer via the test cables for analysis. The experiment obtained nine sets of data, which were recorded in Excel and illustrated using charts. The medians obtained from combining the internal resistance with the residual capacity percentages were used to generate the relation charts for the internal resistances at various load currents to the residual capacity percentages. Finally, 60 Ah was used as the normal capacity to estimate the residual capacity discharging time. Furthermore, a curve-fitting approach for determining the relation equation between internal resistances and capacities was used to replace the table look-up method for residual capacity estimation. The results revealed that the estimation errors after correction were acceptable.     

Active feedback circuit for minimization of voltage transientsduring pulsed measurements of semiconductor devices

The operation of an active feedback circuit that minimizes voltage transients during pulsed-I-V measurements is presented. A field-effect transistor (FET) is used as the nominal device under test (DUT). The feedback circuit detects the sag in drain voltage that is caused by voltage drops produced across both the inductor in the drain bias tee and any series resistance in the drain-current path. The feedback signal consists of the current injected into the drain circuit that is sufficient to minimize the change in drain voltage. The feedback circuit actively synthesizes a small driving-point impedance that is seen by the drain of the DUT and is on the order of 10^-2 Ω. Larger voltages do not need to be applied to the drain circuit in order to overcome the nominal inductive and resistive voltage drops. Therefore, a low-current power supply can be used to set V_ds for low- or high-power FETs. Transient responses with and without the use of the feedback circuit are presented. Pulsed-I-V measurements using this feedback method (made less than 1 μs after the start of the gate pulse) of a high-power FET are also presented     

A New Digtal Method for DC-Current Measurement with Floating Input

This paper describes a new method for direct-current measurement without direct connection to the circuit under test, producing a time-coded indication. A magnetizable ring core with three separate windings is driven to positive and negative saturation by a triangular alternating current. The voltage induced in the detector winding is differentiated. The time interval between two zero-axis crossings of the differentiated voltage is a measure of the current in the measuring winding. Investigations on an experimental setup showed that high resolution and sensitivity and small error of linearity can be achieved. Furthermore the internal resistance can be kept small.     

Direct parameter extraction method for deep submicrometer metal oxide semiconductor field effect transistor small signal equivalent circuit

A new direct parameter extraction method to determine the small signal equivalent circuit model for deep submicrometer metal oxide semiconductor field effect transistors (MOSFETs) is presented here. This method is a combination of the test structure and analytical methods without reference to numerical optimisation. The main advantage of this method is that the extrinsic resistances, inductances, as well as substrate parasitics can be obtained using a set of exact closed equations based on the cut-off mode S-parameter on wafer measurements. Good agreement is obtained between the simulated and measured results for a 90 nm MOSFET in the frequency range of 50-40 GHz over a wide range of bias points.     

一种使用矢量网络分析仪的阻抗测量改进方法

基于反射法理论提出了一种使用矢量网络分析仪测量集总参数元件阻抗的方法,引入阻抗匹配电路,拓宽了矢量网络分析仪的阻抗测量范围.通过对匹配电路二端口网络模型中参量A的分析,给出相应的被测元件的阻抗计算式,消除了夹具对测量结果的影响.采用矢量网络分析仪直接测量法和该阻抗测量法分别测量了5种不同阻值的金属膜电阻,结果表明,该阻抗测量方法的测量精度高于矢量网络分析仪直接测量的精度,可在30 kHz～100 MHz频率范围内实现几欧至千欧阻抗的精确测量.     

频率可调分流扬声器实验研究

分流扬声器是一种将声能转化为机械能进而转化为电能,最后以热能的形式耗散的新型共振吸声体结构,合理设计分流电路参数就可得到分流扬声器所需的固有频率。为了实现分流扬声器固有频率可调,文中提出了电感与负电阻电路串联的分流电路。实验结果表明,在通过负电阻电路抵消扬声器本身内阻后,扬声器固有频率随着电感值的增大而减小,可调范围介于开路与电阻趋于0且不加电感时的频率(98~278 Hz);将分流扬声器应用于管道噪声控制,当分流扬声器的固有频率与管道声模态匹配时,相应声压级可以降低8~10 dB。     

基于交流阻抗法的离子交换膜电阻研究

利用交流阻抗谱测定技术,建立一种离子交换膜导电性能评价方法;使用两极室槽电解池,分别测得电解质溶液,以及膜和电解质溶液之和的电阻值,相减后得到离子交换膜在该电解液中的电阻值.通过并联电阻形成完整的半圆弧形交流阻抗谱,能够有效减小测量误差.利用硫酸水溶液体系、氯化钠水溶液体系,以及全钒液流电池的钒电解液体系验证基于交流阻抗谱的膜电阻测定技术准确性、实用性.在此基础上揭示阳离子交换膜、阴离子交换膜对离子的不同吸附特性,以及膜面电阻对电解质溶液浓度依存特性.研究结果对于发展离子交换膜快速表征技术,以及开发新能源领域的离子交换膜具有重要价值.     

A circuit for lead resistance compensation and complex balancing ofthe strain-gauge bridge

In some specific applications, the strain-gauge bridge branches are separated and remote. Lead resistances between bridge branches and the measuring instrument introduce significant measurement error. The well-known error compensating circuits do not suit all applications, or they cannot be added to the already existing instrumentation without modification of its internal circuits. A circuit for lead resistance compensation and complex balancing of the 1/4 and 1/2, AC or DC excited bridges is described. It is possible to add this circuit in front of the instrumentation already in use with no modification of the instrumentation itself     

Interfacing Differential Resistive Sensors to Microcontrollers: A Direct Approach

This paper introduces and analyzes a novel circuit to directly connect differential resistive sensors to microcontrollers without using either a signal conditioner or an analog-to-digital converter (ADC) in the signal path. This new circuit relies on measuring the discharging time of several resistance-capacitance ( RC) circuits that include the two sensor resistances. Such an operating principle makes the circuit simple, compact, low cost, low power, and accurate. The main uncertainty sources are the quantization of the discharging time measurement and the mismatch of internal resistances of the microcontroller. According to experimental results, the circuit shows errors in the range of 0.01% full-scale span (FSS), and the effective resolution can be up to 13 bits for a measuring time of 100 ms, which are very remarkable considering its simplicity.