MF47万用表原理图

1234ABCD4321DCBATitleNumberRevisionSizeADate:13-Jul-2011SheetofFile:d:\我的文档\桌面\2011年春\MF47万用表原理图.ddbDrawnBy:WH2500-1KR2120KR222.69KD4D346.2μAC110μFWH110KR25R350.5R4555R10.47R280.025DCmaDCV0.55505000.5A+*一、直流电流档1、50μA的电流档由46.2μA表头、电位器WH1、电位器WH2、R21组成。2、0．25V的电压档由50μA的电流档串联R22组成。VVAIVVAIgggg25.01345.0115.026901050115.0508.32.4630000115.02.46115.02500102.462.466611图一MF-47型直流电流档工作原理1234ABCD4321DCBATitleNumberRevisionSizeADate:17-Jul-2011SheetofFile:d:\我的文档\桌面\2011年春\MF47万用表原理图.ddbDrawnBy:WH2500-1KR2120KR222.69KD4D346.2μAC110μFWH110KR7150KR630kR8800KR515KDCV12.510502505000.5A+R122.25MR111.8MR134.5MR10360KR984KACV10502505001k1K*R204.15K图二MF-47型直流电压档工作原理VVVVVVAIVVVVVVVVK1.9918994102.11010)45002250180036084(102.1102.4954494102.11010)2250180036084(102.1102.2472244102.11010)180036084(102.1102.1102.60504150250000505075.4925.010)8001503015(105025.01075.925.010)1503015(105025.05.225.225.010)3015(105025.0175.025.01015105025.0336133650033625025036503610365.2361VVVVVVAIK76.100089941027.11110)45002250180036084(1027.11104.50044941027.11110)2250180036084(1027.11168.24922441027.11110)180036084(1027.11127.11127.61504080250000503361336500336250250二、电阻档（欧姆档）万用表的欧姆档，其原理实质是用伏安法测电阻。它是将测量时用的电压固定，以电流值的大小去反映被测电阻值的大小，图三是MF-47型直流电阻档工作原理电路图123456ABCD654321DCBATitleNumberRevisionSizeBDate:23-Apr-2012SheetofFile:G:\MF47万用表原理图.ddbDrawnBy:WH2500-1KR2120KD4D346.2μAC110μFWH110KR1555.4KR161.78KR17165(1/2)R1815.3(1/2)R1417.3KX100.5A+*R23141KE29VE11.5VX1X100X1KX10K图三（a）MF-47型直流电阻档工作原理电路图123456ABCD654321DCBATitleNumberRevisionSizeBDate:23-Apr-2012SheetofFile:G:\MF47万用表原理图.ddbDrawnBy:WH2500-1KR2120KD4D346.2μAC110μFWH110KR1555.4KR161.78KR17165(1/2)R1815.3(1/2)R1417.3KX100.5A+*R23141KE11.5VX1X100X1KX10KE29V图三(b)MF-47型直流电阻档工作原理电路图123456ABCD654321DCBATitleNumberRevisionSizeBDate:23-Apr-2012SheetofFile:G:\MF47万用表原理图.ddbDrawnBy:WH2500-1KR2120KD4D346.2μAC110μFWH110KR1417.3K0.5A+*R23141KE11.5VX10KE29VWH2500-1KR2120KD4D346.2μAC110μFWH110KR1555.4KR161.78KR17165(1/2)R1815.3(1/2)R1417.3KX100.5A+*E11.5VX1X100X1K123456ABCD654321DCBATitleNumberRevisionSizeBDate:23-Apr-2012SheetofFile:G:\MF47万用表原理图.ddbDrawnBy:WH2500-1KR2120KD4D346.2μAC110μFWH110KR1417.3K0.5A+*R23141KE11.5VX10KE29VWH2500-1KR2120KD4D346.2μAC110μFWH110KR1555.4KR161.78KR17165(1/2)R1815.3(1/2)R1417.3KX100.5A+*E11.5VX1X100X1K图三(c)MF-47型直流电阻×10K档工作原理电路图图三(d)MF-47型直流电阻×1档工作原理电路图