在测量技术和控制技术的领域中,几乎到处都要遇到各种各样的电刷、滑环、触头和开关,利用它们来实现电源或讯号的联接、切换或控制。人们发现一般有接触电路往往存在这样两个缺点:一是可靠性不够好,有时发生接触不良;二是要有较大的正压力,因而摩擦力 In the field of measurement technology and control technology, almost all kinds of brushes, slip rings, contacts and switches are encountered almost everywhere, using them to connect, switch or control power or signals. People found that there are two common shortcomings of the contact circuit: First, the reliability is not good enough, and sometimes bad contact occurs; the second is to have a larger positive pressure, so the friction