【正文】 數(shù)碼管顯示；由“＋”、“－”兩鍵控制輸出電壓步進增減 。 關(guān)鍵詞： AT89S52 單片機, 數(shù)控電源, D/A, 直流電源AbstractThe AT89S52 SCM is the heart of the NC Power,which is made up of Digitalanalog converter module,key module and LED display Output voltage of the syetem is between 2V and +,Stepped by 1V,the ripple is not more than 10mV,and the output current is 500mA,The value of Output voltage is displayed by Digital control,and the stepping change in output voltage is controlled by +and you press the button of the input module,the SCM will have an the one hand ,the SCM transfers the figures into the display module,which display the figures,on the other hand, the SCM transfers the rest information into DAC0832,making it into a simulation of output the operational amplifiers the simulation is changed into the appropriate voltage,which is used to control LM317control ,so it is success in the control of output voltage.Keywords: AT89S52 monolithic integrated circuit, numerical control power source, D/A,directcurrent power supply 目錄摘要 .............................................................................IABSTRACT ........................................................................II1 引言 ...........................................................................12 設計要求 .......................................................................13 方案論證 .......................................................................1 D/A 數(shù)字模擬轉(zhuǎn)換模塊 ........................................................2 可調(diào)穩(wěn)壓芯片 ...............................................................2 按鍵控制模塊 ................................................................2 顯示模塊 ....................................................................34 設計原理 .......................................................................3 單片機模塊 ..................................................................3 單片機介紹 ..............................................................3 單片機外圍電路介紹 .....................................................5 D/A 模塊 ....................................................................6 D/A 電路簡介 ............................................................6 DAC0832 及其外圍電路 ....................................................6 D/A 轉(zhuǎn)換的計算 .........................................................8 LED 數(shù)碼管顯示模塊 .........................................................10 數(shù)碼管顯示簡介 ........................................................10 數(shù)碼管編碼表 ..........................................................11 直流電源 ...................................................................12 直流供電電源制作原理 ...................................................12 輸出電源工作原理 ......................................................135 軟件部分 ......................................................................14 開發(fā)工具介紹 ...............................................................14 程序框圖: ..................................................................156