当电桥为恒流源时惠斯通电桥电压的计算方法http://wenku.baidu.com/link?url=S55C_CbY-IQBl7oqgICODIz765KasqscVU2ACb6xV1OJB1zhLWwvryumayUWtB7V0b3-uHiclyhZtHHMfejUVFuYfdJ-KE2wGv9RqKWiNVi