用运算放大器改进法拉弟电磁感应定律演示实验

Demonstrate Faraday' s Law with An Operational Amplifier

许多物理教材中对法拉弟电磁感应定律的演示都是利用尽可能多匝数的线圈及磁性较强的磁铁,期望产生较 大的感生电流,但实际上往往难以收到良好的效果。利用F741运算放大器及发光二极管对此实验加以改进,收效显著。

In order to generate a high induced EMF, magnets with intensive magnetism and coils with as many as possible turns are usually chosen in the demonstration of Faradays law, but perfect results are rarely achieved. A circuit described in this paper that uses an operational amplifier and two LEDs makes the demonstration better.