Proximity switch with detecting coils - in resonant circuit of oscillator and consisting of flat printed spirals inductively coupled to ferrite plates
摘要
<p>The proximity switch has an approaching object altering the damping of an oscillatory resonant circuit. The oscillator output is demodulated and applied to a digital amplifier. The turns of the detecting coils in the resonant circuit are flat metal spirals on printed circuit boards. The ferrite cores to these spirals are located on the opposite sides of the boards to the spirals and consist of flat plates of roughly the same area as the spirals.</p>
