1.0Electrical Riddlehttps://electrical-riddle.com/faElectrical Riddlehttps://electrical-riddle.com/farich600338<blockquote class="wp-embedded-content" data-secret="btHyql8c9X"><a href="https://electrical-riddle.com/fa/forums/topic/58/">Electrical riddle no.5 – DC Control systems and polarity</a></blockquote><iframe sandbox="allow-scripts" security="restricted" src="https://electrical-riddle.com/fa/forums/topic/58/embed/#?secret=btHyql8c9X" width="600" height="338" title="“Electrical riddle no.5 – DC Control systems and polarity” — Electrical Riddle" data-secret="btHyql8c9X" frameborder="0" marginwidth="0" marginheight="0" scrolling="no" class="wp-embedded-content"></iframe><script> /*! This file is auto-generated */ !function(d,l){"use strict";l.querySelector&&d.addEventListener&&"undefined"!=typeof URL&&(d.wp=d.wp||{},d.wp.receiveEmbedMessage||(d.wp.receiveEmbedMessage=function(e){var t=e.data;if((t||t.secret||t.message||t.value)&&!/[^a-zA-Z0-9]/.test(t.secret)){for(var s,r,n,a=l.querySelectorAll('iframe[data-secret="'+t.secret+'"]'),o=l.querySelectorAll('blockquote[data-secret="'+t.secret+'"]'),c=new RegExp("^https?:$","i"),i=0;i<o.length;i++)o[i].style.display="none";for(i=0;i<a.length;i++)s=a[i],e.source===s.contentWindow&&(s.removeAttribute("style"),"height"===t.message?(1e3<(r=parseInt(t.value,10))?r=1e3:~~r<200&&(r=200),s.height=r):"link"===t.message&&(r=new URL(s.getAttribute("src")),n=new URL(t.value),c.test(n.protocol))&&n.host===r.host&&l.activeElement===s&&(d.top.location.href=t.value))}},d.addEventListener("message",d.wp.receiveEmbedMessage,!1),l.addEventListener("DOMContentLoaded",function(){for(var e,t,s=l.querySelectorAll("iframe.wp-embedded-content"),r=0;r<s.length;r++)(t=(e=s[r]).getAttribute("data-secret"))||(t=Math.random().toString(36).substring(2,12),e.src+="#?secret="+t,e.setAttribute("data-secret",t)),e.contentWindow.postMessage({message:"ready",secret:t},"*")},!1)))}(window,document); //# sourceURL=https://electrical-riddle.com/wp-includes/js/wp-embed.min.js </script>Control and protection electrical circuits are one of the important portions of electrical systems designed and shown by standard symbols. Usually the circuit is supplied by positive and negative polarity of one battery. In almost electrical circuit diagram sheets we can see a positive line of DC polarity in top of sheet and negative line … ادامه »https://electrical-riddle.com/wp-content/uploads/2021/08/1365929675_7.gif