【正文】 ractWith the power technical progress, NC adjustable power supply power have bee the most popular object of research areas, the prominent feature of the NC is NC embodied in the microcontroller as the core to achieve the power output voltage design of the microcontroller chip for the 89 C51. first, Through digital keyboard input voltage, and then voltage values in the digital display on the final through D / A converters are analog output voltage. This article on the NC adjustable power supply design.Firstly, the NC adjustable power supply of choice to do a simple background briefing, a prehensive summary of the NC concept of power, features and design ideas, and other aspects.Secondly, the NC adjustable power supply design to the system introduced. This paper presented by the NC adjustable power supply design, including a total of two parts of the design: hardware circuit design and software systems design. Hardware, including: the power supply design, figures show circuit, keyboard circuit, SCM circuits, digital / analog converter circuit, analog amplifier and the output current overcurrent protection circuit. Software includes: MCS module initialization and the implementation procedures. Initialized which include: adjusted stack pointer, the need to use the internal data memory of the initialization, set up the boot NC power output voltage and CPU interruption of the set.In succession, that is software and hardware integration, the overall realization of the power of the NC digital election, numerical adjustments characteristics.Finally, the results do the overall design overview and analysis. This includes some of the problems encountered in the design, the choice of ponents and personal experience and so on.Key words: NC adjustable power supply。 figures show。 numerical adjustment II目 錄1 緒論 .......................................................................................................................................1 簡介 .................................................................................................................................1 論文選題背景 .................................................................................................................1 論文研究內(nèi)容及結(jié)構(gòu) .....................................................................................................2 論文研究的主要內(nèi)容 ..............................................................................................2 論文結(jié)構(gòu) ..................................................................................................................22 系統(tǒng)電源的設(shè)計 ...................................................................................................................4 穩(wěn)壓電源的基本原理 .....................................................................................................4 穩(wěn)壓電源的原理圖 .........................................................................................................5 紋波處理 .........................................................................................................................5 紋波的概念 ..............................................................................................................6 紋波的害處 ..............................................................................................................6 紋波電壓的抑制方法 ..............................................................................................63 硬件電路設(shè)計 .......................................................................................................................7 硬件系統(tǒng)結(jié)構(gòu)框架 .........................................................................................................7 單片機發(fā)展和組成 .........................................................................................................7 單片機的組成 ..........................................................................................................8 89C51 單片機的引腳描述及片外總線結(jié)構(gòu) ..........................................................9 譯碼顯示電路 ...............................................................................................................11 輸入、輸出接口 P0～P3 ......................................................................................11 并行輸入/輸出口概述 ...........................................................................................11 串行輸入/輸出口概述 ...........................................................................................11 數(shù)碼管 ....................................................................................................................13 基于串行輸入/輸出口的數(shù)碼管電路 ...................................................................14 數(shù)字/模擬轉(zhuǎn)換電路 ......................................................................................................16 DAC0832 數(shù)字/模擬轉(zhuǎn)換器的應(yīng)用 .....................................................................16 DAC0832 數(shù)字/模擬轉(zhuǎn)換器的介紹 .....................................................................16 III 鍵盤電路 .......................................................................................................................19 中斷系統(tǒng)介紹 ........................................................................................................19 鍵盤電路 ................................................................................................................23 放大電路的設(shè)計 ...........................................................................................................28 保護電路的設(shè)計 ...........................................................................................................28 硬件部分的系統(tǒng)設(shè)計 ...................................................................................................304 軟件系統(tǒng)設(shè)計 .....................................................................................................................325 結(jié)束語 .............................................................................................................