电桥电路 BRIDGE CIRCUITS SECTION 2 BRIDGE CIRCUITS Walt Kester INTRODUCTION This section discusses the fundamental concepts of bridge circuits, and is followed by a section on precision op amps (Section 3). Section 4 focuses on the detailed application circuits relating to strain gage-based sensors. Sections 2 and 4 can be read sequentially if the reader already understands the design issues relating to op amps which are covered in Section 3. Resistive elements are some of the most common sensors. They are inexpensive to manufacture and relatively easy to interface with signal conditioning circuits. Resistive elements can be made sensitive to temperature, strain (by pressure or by flex), and light. Using these basic elements, ma……