【導(dǎo)讀】本次設(shè)計的對象是一個三位半直流數(shù)字電壓表。電路主要由雙積分模/數(shù)轉(zhuǎn)換器、譯碼驅(qū)動器、反。相器等器件構(gòu)成的。當(dāng)被測電壓輸入模/數(shù)轉(zhuǎn)換器后，在位選信號有效期。通脈沖輸出端控制反相器輪流導(dǎo)通，產(chǎn)生顯示器的位驅(qū)動信號。顯示方式采用了由發(fā)光二極管組成的共陰極LED顯示器。位驅(qū)動信號共同作用下在顯示屏上顯示所要測量的直流模擬電壓。器的消引端的電平時高時低，從而使顯示數(shù)字閃爍，指示過量程狀態(tài)。的輸入端接一只開關(guān)，可以實現(xiàn)電壓表保持某一時刻的測量結(jié)果不變。自動轉(zhuǎn)換量程可以加快測量速度，提高測。量準(zhǔn)確度，實現(xiàn)測量自動化。優(yōu)點，被廣泛用于各種數(shù)字儀表中。

　　

【正文】 出版社， 1985： 459600. 2 蔡明生 .電子設(shè)計 [M].北京：高等教育出版社， 2021： 7483. 3 彭介華 .電子課程設(shè)計指導(dǎo) [M].長沙：高等教育出版社， 1997： 177181. 4 何小艇 .電子系統(tǒng)設(shè)計 [M].杭州：浙江大學(xué)出版社， 1998： 209216. 5 肖景和 .CMOS 數(shù)字電路應(yīng)用 [M].北京：中國電力出版社， 2021： 276. 6 蔡惟錚 .集成電子技術(shù) [M].北京：高等教育出版社， 2021： 112124. 7 陳澎，曾永和 .電子技術(shù) [M].長沙：湖南大學(xué)出版社， 2021： 318320. 8 楊振江，蔡德芳 .新型集成電路使用指南與典型應(yīng)用 [M].西安：西安電子科技大學(xué)出版社， 132136. 9 高維坤，史先武，王秀山 .現(xiàn)代電子工藝技術(shù)指南 [M].北京：科學(xué)技術(shù)文獻(xiàn)出版社， 2021： 86. 10 黃繼昌 .電子元器件應(yīng)用手冊 [M].北京：人民郵電出版社， 2021：151154. 11 何希才 .新型集成電路及其應(yīng)用實例 [M].北京：科學(xué)出版社， 2021：171178. 12 王克義 .李潔 .電子技術(shù)與數(shù)字電路 [M].北京：北京大學(xué)出版社，1995： 297301. 13 馬建國 .電子系統(tǒng)設(shè)計 [M].北京：高等教育出版社， 2021： 297320. 14 彭利標(biāo) .電子技術(shù)基礎(chǔ) [M].北京：高等教育出版社， 2021： 223225. 15 浙江大學(xué)電工電子基礎(chǔ)教學(xué)中心電工學(xué)組，張伯克 .應(yīng)用電子學(xué) [M]， 杭州：浙江大學(xué)出版社 .2021： 307315. 16 楊紅孺 .電子技術(shù)基礎(chǔ) 數(shù)字電路 [M].哈爾濱：哈爾濱地圖出版社， 2021： 110127. 17 羅華 .電子技 術(shù)基礎(chǔ) 模擬電路 [M].哈爾濱：哈爾濱地圖出版社，2021： 1416. 18 TMS320C54xOPtimizingCComPilerUser’. 1997 19 ， 1997 20 ， 2021 哈爾濱理工大學(xué)遠(yuǎn)東學(xué)院學(xué)士學(xué)位論文 27 附錄 A Digital voltage meter introduced Digital voltage meter from the A / D conversion, data processing and display control of the measurement range of 0 ~ input voltage value, from a total of three digital tube 7 overcast scan showed that the maximum resolution of , the error 177。 . The core digital voltage meter for AT89S51 MCU and ADC0809 A / D conversion chip. ADC0809 chip latch function with 8channel analog signal input switch 8 input analog signal conversion time, with multiway switches and latches the address decoding circuit, 8bit A / D converter, and a threestate such as the output latch. Different from the singlechip channel select control input analog signal to the ALE (address latch side) to choose a positive pulse signal of the address latch signal to start A / D analogtodigital conversion, when the A / D conversion after the end of, EOC HIGHended output, singlechip began to read the A / D conversion data. Singlechip microputer for data processing, the binary number as a decimal number into the BCD code, the final adoption of the dynamic scan 4511BCD decoder digital display drive voltage. By adjusting the potentiometer input to achieve a wider range of voltage measurement, but accuracy will be reduced accordingly, the error will increase accordingly. Referred to as digital voltage meter DVM, it is a digital measurement technology, the continuous analog (DC input voltage) into a noncontinuous, discrete digital form and the instrument display. Digital voltage meter since its inception in 1952, with the rapid development of electronic technology, especially now, as measuring instruments, analog instructions digital instruments as well as automatic measurement system, which has been great. 哈爾濱理工大學(xué)遠(yuǎn)東學(xué)院學(xué)士學(xué)位論文 28 Digital voltage meter (DVM indicated below), is a potential difference from the idea of automation developed, so even if the initial DVM, of its accuracy than analog meters high, and potential difference than the cost of also high. Later, DVM focus in the development of both high precision and low cost. Digital Voltage Meter have the following characteristics: (1). Show a clear intuitive, accurate readings: the traditional analog instrumentation through the use of indicators must be carried out and dial readings in the reading process will be introduced to the inevitable human error. Digital voltage meter is the use of advanced digital display technology, so that the measurement results at a glance, as long as the meter jump phenomenon does not occur, the measurement results is unique. New Digital Voltmeter identifier has also increased the display, including measurements, symbols and special unit symbols, to resolve the DVM does not reflect the measured changes in voltage, as well as the continuous trend of this problem, a digital / analog bar graph instrumentation has been available DVM (Digital Voltmeter) referred to as DVM, it is a digital measurement technology, the continuous analog (DC input voltage) into a noncontinuous, discrete digital form and the instrument display. At present, from a variety of singlechip A / D converter consisting of digital voltage meter, has been widely used in electronics and electrical measurement, industrial automation instruments, automated test systems, showing strong vitality. At the same time, the expansion of the DVM from the various general and dedicated digital instrumentation, but also the power and nonpower measurement technology to new levels. This chapter focuses on a single A / D converter as well as they constitute a variety of new digital voltage meter works. Digital voltage meter has the following ten characteristics: ⑴ show a clear intuitive, accurate readings of the traditional analog instrumentation through the use of indicators must be carried out and dial readings in the reading process will inevitably introduce artificial measurement error (eg, parallax), and easily 哈爾濱理工大學(xué)遠(yuǎn)東學(xué)院學(xué)士學(xué)位論文 29 lead to visual fatigue. Digital voltage meter is the use of advanced digital display technology, so that the measurement results at a glance, as long as the instrument does not hop phenomenon, is the only measurement results, not only to ensure the objectivity and accuracy of reading, but also in line with people39。s reading habits, can reduce the reading and record time. New Digital Voltmeter identifier has also increased the display, including the measurement of project symbols, unit symbols and special symbols. ⑵ shows the median show that the median is usually 3 ~ 8 to determine the median number of instruments there are two principles: ① can display from 0 to 9 All figures are integer values。 ② Scorebit numerical value is based on the largest show the hi ghestdigit for the elements, with a maximum fullscale dodigit denominator. ⑶ high accuracy is a measure of the accuracy of the re