本文選題：電流 + 并聯(lián)��； 參考：《河北大學(xué)》2017年碩士論文

【摘要】：隨著社會(huì)的智能化和科學(xué)技術(shù)日新月異發(fā)展的年代,在日常的生活和學(xué)習(xí)中越來(lái)越多接觸到新的電子產(chǎn)品,PCB電路板構(gòu)成的產(chǎn)品在常規(guī)檢測(cè)與維修工作上成了產(chǎn)品檢驗(yàn)的有力的保障。批量檢測(cè)電路板的好壞和電路電流的檢測(cè)技術(shù)亟待進(jìn)一步簡(jiǎn)便、快捷、精準(zhǔn)的測(cè)量。通常電流測(cè)量時(shí)需要將測(cè)量?jī)x表串聯(lián)接入電路,或者將被測(cè)導(dǎo)線穿過(guò)測(cè)量磁環(huán)。因此,研究一種可以與導(dǎo)線并聯(lián)測(cè)量電流的方法,在PCB等電流測(cè)量檢測(cè)等場(chǎng)合可帶來(lái)便利,具有實(shí)用意義。本研究通過(guò)分析常見(jiàn)幾種電流測(cè)量方法,深入分析其適用場(chǎng)合和測(cè)量利弊,針對(duì)目前PCB電路板在線測(cè)量的市場(chǎng)現(xiàn)象,設(shè)計(jì)了一種低成本、可以與微小阻值導(dǎo)線并聯(lián)測(cè)量導(dǎo)線中電流的方法和電路。本測(cè)試電路依托運(yùn)算放大器的特性和工作方式,選用具備高增益、低失調(diào)的高精度型運(yùn)算放大器為核心器件,設(shè)計(jì)實(shí)現(xiàn)了并聯(lián)式電流測(cè)量方法。此種方法改變了在傳統(tǒng)測(cè)量PCB板電流的檢測(cè)方法會(huì)在某些特定的場(chǎng)合給測(cè)試的帶來(lái)不便,使其在PCB電路板測(cè)試檢修等較小電流情況實(shí)現(xiàn)不需要斷開(kāi)PCB銅箔線條即可測(cè)量電流。本文設(shè)計(jì)給出了一種并聯(lián)式電流測(cè)量電路,包括基于OP177型精密運(yùn)放的主測(cè)量電路,以及由取樣電阻和IRF630型VMOS管等構(gòu)成的測(cè)量電流量程擴(kuò)展電路。論文對(duì)電路原理進(jìn)行了詳細(xì)分析和仿真。對(duì)元器件的遴選進(jìn)行了分析對(duì)比。采用PROTEUS對(duì)設(shè)計(jì)的電路進(jìn)行了仿真驗(yàn)證。仿真結(jié)果表明,當(dāng)被測(cè)導(dǎo)線阻值在≥50mΩ時(shí),2mA~200mA范圍內(nèi)電流測(cè)量誤差≤4%,在3mA~200mA范圍內(nèi)電流測(cè)量誤差㩳3%。實(shí)際搭建電路中當(dāng)被測(cè)導(dǎo)線阻值在≥50mΩ時(shí),2mA~200mA范圍內(nèi)電流測(cè)量誤差≤6%,在4mA~200m A范圍內(nèi)電流測(cè)量誤差㩳2%。測(cè)試表明,該電路可以實(shí)現(xiàn)并聯(lián)電流的測(cè)量,測(cè)量誤差及變化趨勢(shì)和仿真結(jié)果基本相符。主要是由于仿真的環(huán)境為理想的環(huán)境下測(cè)量而實(shí)際測(cè)量電路的時(shí)候受實(shí)驗(yàn)設(shè)備、環(huán)境、人為讀數(shù)等諸多因素的影響。
[Abstract]:With the society's intelligence and the rapid development of science and technology, In the daily life and study, more and more products made up of new electronic products, PCB circuit board, have become the powerful guarantee of product inspection in the routine inspection and maintenance work. The quality of the circuit board and the current detection technology need to be further simple, fast and accurate measurement. Current measurement usually involves connecting the instrument in series to the circuit or traversing the measuring ring. Therefore, it is of practical significance to study a method for measuring current in parallel with conductors, which can be used in PCB and other situations. Through analyzing several common current measurement methods, the paper deeply analyzes the applicable situation, advantages and disadvantages of the measurement, and designs a low cost for the current market phenomenon of online measurement of PCB circuit board. A method and circuit for measuring the current in a wire in parallel with a small resistance conductor. Based on the characteristics and working mode of the operational amplifier, this test circuit chooses the high gain and low offset high precision operational amplifier as the core device, and designs and implements the parallel current measurement method. This method changes the traditional method of measuring the current of PCB board, which will bring inconvenience to the test in some special occasions, and make it realize that the current can be measured without disconnecting the copper foil line of PCB in smaller current condition such as PCB circuit board test and repair. In this paper, a parallel current measuring circuit is designed, including the main measuring circuit based on OP177 precise operational amplifier, and the measuring current range expanding circuit composed of sampling resistor and IRF630 type VMOS transistor. The circuit principle is analyzed and simulated in detail. The selection of components is analyzed and compared. The designed circuit is verified by PROTEUS. The simulation results show that the error of current measurement is 鈮，

本文編號(hào)：1934663