2951 4.3 Relative Displacement:Translational and Rotational VI.Variable--Inductance(电感)&Variable-Reluctance(磁阻)Pickups (o] Accurately center-topped tronsformer Two possible methods of exciting transducer ond forming bridge circuit Figure 4.28 (6) Variable-inductance pickup 30/51 4.3 Relative Displacement:Translational and Rotational VIl.Eddy-Current()Noncontacting Transducers Bridge circuit Active Balance Phase- coil coil sensitive demodulator and low-pass filter Electrically conducting material Figure 4.31 Eddy-current noncontacting transducer (Commercially available with full-scale ranges from 0.25mm to 30mm, and maximum resolution 0.0001mm)4.3 Relative Displacement: Translational and Rotational VI. Variable-Inductance(电感) & Variable-Reluctance(磁阻) Pickups Figure 4.28 Variable-inductance pickup 29/51 4.3 Relative Displacement: Translational and Rotational VII. Eddy-Current(涡流) Noncontacting Transducers Figure 4.31 Eddy-current noncontacting transducer (Commercially available with full-scale ranges from 0.25mm to 30mm, and maximum resolution 0.0001mm) 30/51