1、直流電子負(fù)載一、根本要求1負(fù)載工作模式：恒壓 (CV)、恒流 (CC)兩種模式可選擇。2電壓設(shè)置及讀出范圍：1.00 V 20.0 V。3電流設(shè)置及讀出范圍：100 mA 3.00 A。4顯示分辨力及誤差：至少具有三位數(shù)，相對誤差小于5%。二、總體方案論證與設(shè)計顯 示按鍵輸入單片機AD轉(zhuǎn)換轉(zhuǎn)換 電流檢測電壓檢測恒壓恒流2.1參數(shù)設(shè)計方案利用A/D轉(zhuǎn)換把模擬信號轉(zhuǎn)換為數(shù)字信號，在利用單片機程控來修改電壓電流參數(shù)，此方案精確度高，操作技術(shù)要求很高，節(jié)省時間。并且用采集顯示測量值，比擬得出結(jié)論。2.2恒流恒壓設(shè)計方案1 定電流模式CC mode在定電流工作模式時，電子負(fù)載所流入的負(fù)載電流依據(jù)所設(shè)定的

2、電流值而保持恒定，與輸入電壓大小無關(guān)，即負(fù)載電流保持?jǐn)z定值不變。定電壓模式CV mode在定電壓工作模式時，電子負(fù)載所流入的負(fù)載電流依據(jù)所設(shè)定的負(fù)載電壓而定，此時負(fù)載電流將會增加直到負(fù)載電壓等于設(shè)定值為止，即負(fù)載電壓保持設(shè)定值不變。.電源模塊設(shè)計電源模塊根本電路圖.單片機模塊設(shè)計單片機模塊根本電路三、測試及分析測試原始數(shù)據(jù).恒流模式數(shù)據(jù)測量模式設(shè)定值A(chǔ)測量值1(A)測量值2(A)測量值3(A)工作電壓(V)工作電壓(V)工作電壓(V)恒流0.370.430.430.430.852.083.49恒流0.750.760.760.761.232.434.45恒流1.131.151.151.15 1.

3、424.095.38恒流 1.701.721.721.722.294.666.22恒流1.891.911.911.913.245.356.87.恒壓模式數(shù)據(jù)測量模式設(shè)定值(V)測量值1(V)測量值2(V)測量值3(V)工作電壓(V)工作電壓(V)工作電壓(V)恒壓1.111.121.121.121.683.817.40恒壓3.113.16 3.08 3.14 4.877.3410.25恒壓9.008.96 9.04 9.0410.0312.2715.33恒壓15.2215.1615.24 15.1815.4917.7819.34恒壓20.0019.9219.84 19.9020.2221.12

4、 22.23四、附錄根本程序恒流模塊#include #include#define uint unsigned int#define uchar unsigned charsbit rs=P27;sbit E=P26;sbit adwr=P25;sbit adrd=P24;float adval;long int temp;void delay(uint z) /延時子程序 uint x,y; for (x=z;x0;x-) for(y=110;y0;y-);write_com(uchar com) /寫命令 rs=0; P0=com; delay(5); E=1; delay(5); E=

5、0; write_data(uchar dat) /寫數(shù)據(jù) rs=1; P0=dat; delay(5); E=1; delay(5); E=0;init() /液晶初始化 E=0; write_com(0x38); write_com(0x0c); write_com(0x06); write_com(0x01); write_com(0x80+3); void Display_Resulti(uchar dac) /恒流設(shè)定值子程序 float db=0.0; uchar shi=0,ge=0,xs=0,xxs=0; P3=dac; db=dac*3.00/158.00; shi=(int

6、)db/10; ge=(int)db%10; db*=10.0; xs=(int)db%10; db*=10.0; xxs=(int)db%10; write_com(0x80+1); delay(2); write_data(c); delay(2); write_data(u); delay(2); write_data(r); delay(2); write_data(r); delay(2); write_data(e); delay(2); write_data(n); delay(2); write_data(t); delay(2); write_data(0x3a); dela

7、y(2); if(shi=0) write_data(0x20); delay(2); else write_data(0X30+shi); delay(2); write_data(0X30+ge); delay(2); write_data(0x2e); delay(2); write_data(0x30+xs); delay(2); write_data(0x30+xxs); delay(2);void Display_Resulti1(float adval) /測量電流值子程序 uchar ge,xs,shi,xxs; temp=(long int)(adval*105/51); s

8、hi=temp/1000; ge=temp/100%10; xs=temp/10%10; xxs=temp%10; write_com(0x80+0x40+1); delay(2); write_data(C); delay(2); write_data(U); delay(2); write_data(R); delay(2); write_data(R); delay(2); write_data(E); delay(2); write_data(N); delay(2); write_data(T); delay(2); write_data(0x3a); delay(2); if(sh

9、i=0) write_data(0x20); delay(2); else write_data(0X30+shi); delay(2); write_data(0X30+ge); delay(2); write_data(0x2e); delay(2); write_data(0x30+xs); delay(2); write_data(0x30+xxs); delay(2);void ADC() /啟動AD轉(zhuǎn)換 adwr=1; _nop_(); adwr=0; _nop_(); adwr=1; P1=0xff; adrd=1; _nop_(); adrd=0; _nop_(); adval

10、=P1; adrd=1;void main() /主程序 init(); TMOD = 0x02; /定時器初始化TH0 = 0x6f;TL0 = 0x00;IE = 0x82;TR0 = 1; while(1) /顯示模塊 uchar key=0;bit keyflag=1;uint dac=0; Display_Resulti(dac); while(1) /鍵盤掃描控制顯示 Display_Resulti1(adval); ADC();key=P2&0x0f; switch(key)case 0x0e:if(keyflag) dac=0; Display_Resulti(dac); ke

11、yflag=0;break; case 0x0d: if(keyflag) dac+=10;Display_Resulti(dac); keyflag=0;break; case 0x0b: if(keyflag) dac-=10;Display_Resulti(dac);keyflag=0;break; case 0x07: if(keyflag) dac=158;Display_Resulti(dac); keyflag=0;break; case 0x0f: keyflag=1; break; 恒壓模塊#include #include#define uint unsigned int#

12、define uchar unsigned charsbit rs=P27;sbit E=P26;sbit adwr=P25;sbit adrd=P24;float adval;long int temp;void delay(uint z) /延時子程序 uint x,y; for (x=z;x0;x-) for(y=110;y0;y-);write_com(uchar com) /寫命令 rs=0; P0=com; delay(5); E=1; delay(5); E=0; write_data(uchar dat) /寫數(shù)據(jù) rs=1; P0=dat; delay(5); E=1; de

13、lay(5); E=0;init() /液晶初始化 E=0; write_com(0x38); write_com(0x0c); write_com(0x06); write_com(0x01); write_com(0x80+3); void Display_Resultu1(float adval) /恒壓設(shè)定值子程序 uchar ge,xs,shi,xxs; temp=(long int)(adval*110/51); temp=temp*4; shi=temp/1000; ge=temp/100%10; xs=temp/10%10; xxs=temp%10; write_com(0x8

14、0+0x40+1); delay(2); write_data(V); delay(2); write_data(O); delay(2); write_data(L); delay(2); write_data(T); delay(2); write_data(A); delay(2); write_data(G); delay(2); write_data(E); delay(2); write_data(0x3a); delay(2); if(shi=0) write_data(0x20); delay(2); else write_data(0X30+shi); delay(2); w

15、rite_data(0X30+ge); delay(2); write_data(0x2e); delay(2); write_data(0x30+xs); delay(2); write_data(0x30+xxs); delay(2);void Display_Resultu(uchar dac) /測量電壓子程序 float db=0.0; uchar shi=0,ge=0,xs=0,xxs=0; P3=dac; db=dac*20.00/255.00; shi=(int)db/10; ge=(int)db%10; db*=10.0; xs=(int)db%10; db*=10.0; x

16、xs=(int)db%10; write_com(0x80+1); delay(2); write_data(v); delay(2); write_data(o); delay(2); write_data(l); delay(2); write_data(t); delay(2); write_data(a); delay(2); write_data(g); delay(2); write_data(e); delay(2); write_data(0x3a); delay(2); if(shi=0) write_data(0x20); delay(2); else write_data

17、(0X30+shi); delay(2); write_data(0X30+ge); delay(2); write_data(0x2e); delay(2); write_data(0x30+xs); delay(2); write_data(0x30+xs); delay(2);void ADC() /啟動AD轉(zhuǎn)換 adwr=1; _nop_(); adwr=0; _nop_(); adwr=1; P1=0xff; adrd=1; _nop_(); adrd=0; _nop_(); adval=P1; adrd=1;void main() /主程序 init(); TMOD = 0x02; /定時器初始化TH0 = 0x6f;TL0 = 0x00;IE = 0x82;TR0 = 1; while(1) /顯示模塊 uchar key=0;bit keyflag=1;uint dac=0; Display_Resultu(dac); while(1) /鍵盤掃描控制顯示 Display_Resultu1(adval); ADC();key=P2&0x0f; switch(key)case 0x0e:if(keyflag) da