Principle of the centered rotary cap variable capacitor. Based on drawings <a href="//commons.wikimedia.org/wiki/User:Elcap" title="User:Elcap">Elcap</a>.
Zátonyi Sándor, (ifj.) <a href="//commons.wikimedia.org/wiki/User:Fizped" title="User:Fizped">Fizped</a>
<span class="int-own-work" lang="en">Own work</span>