電子機電論文編號:JD038    字數:8160,頁數:33

目錄
摘要............................................................ I
Abstract ........................................................ II

1. 緒論 ...........................................................1
1.1. 電流源簡介 ...................................................1
1.2. 數控電流源的必要性........................................... 1
1.3. 數控電流源的可行性........................................... 1
2. 數控電流源硬件系統總體設計....................................  2
2.1. 傳統電流源的設計方案........................................  2
2.2. 數控電流源方案 .............................................. 2
2.3. 數控電流源的方案比較........................................  3
2.4. 電流源的軟件系統組成 ........................................ 4
2.5. 本系統的特點................................................  5
3. 數控電流源硬件模塊設計........................................  6
3.1. 電源模塊 .................................................... 6
3.1.1. 電源原理................................................... 6
3.1.2. 電源方案確定 ...............................................7
3.1.3. 電源模塊具體電路 ...........................................8
3.1.4. 電源模塊PCB設計 ............................................8
3.1.5. 顯示模塊 .................................................. 8
3.2. D/A電路...................................................... 10
3.2.1. DAC0832簡介 ................................................10
3.2.2. 具體電路設計 .............................................. 12
3.2.3. 控制電壓產生電路..........................................  13
3.3. 電流輸出模塊 ................................................ 14
3.3.1. 具體電路圖................................................. 15
3.3.2. 電流輸出模塊Pcb圖 ..........................................16
3.4. 主控部分..................................................... 16
3.4.1. AT89C52單片機系統及外圍電路 ................................16
3.4.2. 單片機時鐘脈沖電路........................................  16
3.4.3. 復位電路 .................................................. 16
3.4.4. 主控部分具體電路 .......................................... 18
4. 數控電流源的軟件系統設計 ...................................... 19
4.1. 具體模塊劃分 ................................................ 19
4.2. 數值處理..................................................... 20
5. 系統測試 .......................................................21
5.1. 設計創新點....................................................21
5.2. 系統性能檢測 ................................................ 21
5.2.1. 減小紋波所采用的措施 ...................................... 22
5.2.2. 紋波電流測試............................................... 22
5.3. 誤差分析 .................................................... 24
6. 結論 .......................................................... 25

致謝 ............................................................. 26
參考文獻...........................................................27
附錄1 ............................................................ 28
附錄2............................................................  29

摘 要
隨著電子技術的不斷進步，對電子儀器的要求也不斷提高。電源作為電路的動力源泉更是扮演著越來越重要的角色，不論是學校實驗室還是維修中心都離不開實驗電流源，然而傳統的電流源不論是在控制精度還是輸出特性上都無法滿足要求。
隨著單片機技術的不斷發展和D/A，A/D技術的不斷成熟使得數控電源成為可能，數控電流源不論是在控制精度還是在可操作性上都有傳統電源無法比擬的優勢。
本文在參考傳統電流源以及普通數控電流源的基礎上，在充分考慮性價比的同時極大地提高了數控電流源的準確性，通過軟件修正以后在使用普通元件的情況下數控電流源的性能也達到了比較高的水平。
關鍵字：高精度； DAC0832；D/A轉換；恒流源；軟件修正  
Abstract: Progress unremittingly the request to the electronics instrument technically to also raise continuously along with the electronics, the power supply is the motive source of the electric circuit to play a more and more important role more, is the school a laboratory still repair centerses to all can not get away from an experiment power supply in spite of, however the traditional power supply is control accuracy or output the tops of the characteristic in spite of and can't satisfy a request.
Along with single slice machine technical of develop continuously with the D/A, the A/D is technical continuously the maturity make the number control power supply to make possible, count to control the electric current source and is control accuracy in spite of still on the maneuverability all there is traditional power supply can't compare to of advantage.
This text in making reference to the foundation that the traditional electric current source and common number control the electric current source, at the full consideration price compare of in the meantime raised a number to control the accuracy of the electric current source biggest, pass the software correction hereafter while use the circumstance of the common component the number controls the electric current source of the function also comes to a higher level.
Key words:  High accuracy；DAC0832；D/A converter；Constant； current resource