5、万用表测试直流电压、电流,交流电压、电流,以及电阻,测量值与实际准确值相符很好,误差在可接受的范围内,也说明了用运算放大器设计的万用表电路的可行性。关键词:运算放大器;万用表;小信号放大Multimeter Design Based on theOperationalAmplifierXX(JishouUniversity,Jishou,Hunan,416000)AbstractMultimeter alsonamed the multimeter or three tables,mainlyforthemeasurementof voltage, current,re
6、sistance. Inthemeasurement, the multimeter,access shouldnot affect theoriginal status of the circuitundertest,whichrequiresa voltmeter shouldhave infiniteinput resistance, theinternalresistance of theammeter shouldbezero. Operationalamplifiers, the ohmmeter cannotonly be alinear scale,bu
7、talso toachieve the automaticzeroadjustment. The operationalamplifier circuitperformancewill directlyaffectthe performance of the multimeter.Thispaperfirst describes the structure,theory of operationalamplifier circuit.Thendesignedmultimetercircuit usingoperationalamplifi