暂将2欧移离，开口端上a下b，馀下电路有受控电压源 4I' ，设有电流 i' 从24v流出，24v = 4i' + 6i' ，i' = 2.4A，又i' = I'Uab = 24 x 6/10 - 4I' = 14.4 - 9.6 = 4.8v，Req = Rab = 4//6 = 2.4欧，戴维南等效电路为 4.8v串2.4欧，接回2欧到戴维南等效电路，U = 4.8 x 2/(2+2.4) = 2.18v。
