3.1.3不平衡电桥法U(I)U(I)U(I)U(I)R+ARR+ARR-ARR-ARRoUo0oUo°oUooUoR+ARR+ARR+ARR+ARR-AR(b)(c)da)图3-1-5电阻传感器电桥的实例△RUARU△RU△RU. =U.U。~U.U。~UU.=-242RRRR1△RU°-UU°-U△R1.e=-2e=0e=0RUoes2 U。R
3.1.3 不平衡电桥法 图3-1-5 电阻传感器电桥的实例 R U R U U = 4 0 0 R R U U U e = − = 2 1 0 0 0 R U R U U = 2 0 0 R R U U U e = − = 2 1 0 0 0 R U R U = 2 0 0 R U U R = e = 0 e = 0
E-2（a）电阻平衡臂电桥（b）变压器电桥图3-1-6两种交流电桥ER-R:112R+R.EEZ,-ZUo=H22+Z,7.1+ZE C-C2EL-LUoUo=2 L, +L,2 C, +C2
图3-1-6 两种交流电桥 1 2 2 1 1 2 2 0 2 2 Z Z E E Z Z Z Z Z U E + − − = + = • • • • 1 2 2 1 0 2 R R E R R U + − = • • . . 2 1 0 1 2 2 E L L U L L − = + . . 1 2 0 1 2 2 E C C U C C − = +
b工(Cd图3-1-7有源电桥EE1ARARARE △RU.U。=-E2AR4R2R+△R1-R2R2R
图3-1-7 有源电桥 0 1 2 2 4 1 2 E R E R U R R R R R = = + + 0 2 E R U R = − 0 R U E R = −