{"id":512,"date":"2019-06-06T21:39:52","date_gmt":"2019-06-07T04:39:52","guid":{"rendered":"https:\/\/unixwizardry.com\/?p=512"},"modified":"2022-12-17T22:26:14","modified_gmt":"2022-12-18T06:26:14","slug":"a-circuit-to-operate-an-led-on-120v-mains","status":"publish","type":"post","link":"https:\/\/unixwizardry.com\/index.php\/2019\/06\/06\/a-circuit-to-operate-an-led-on-120v-mains\/","title":{"rendered":"A Circuit to operate an LED on 120V Mains"},"content":{"rendered":"<p>So, if you look at my post about Node-RED experiments and my portable powered breadboard, you&#8217;ll notice that the &#8220;power&#8221; LED isn&#8217;t lit on my home-made portable breadboard.\u00a0 I could have just wired the LED to the +5 of the power supply, but if the supply died then all lights would be out, including the &#8220;power&#8221; LED, which wouldn&#8217;t really be much help in diagnosing the problem.\u00a0 I found this circuit\u00a0 <a href=\"https:\/\/www.eeweb.com\/extreme-circuits\/mains-operated-led-circuit-schematic\">https:\/\/www.eeweb.com\/extreme-circuits\/mains-operated-led-circuit-schematic<\/a> that uses the capacitive reactance at 60Hz to bring the current to the LED to about 10mA.\u00a0 Here&#8217;s the circuit.\u00a0\u00a0 (I used two 0.1mF at 400WV for C1 and C2)<\/p>\n<figure id=\"attachment_513\" aria-describedby=\"caption-attachment-513\" style=\"width: 300px\" class=\"wp-caption alignnone\"><img decoding=\"async\" class=\"size-medium wp-image-513\" src=\"https:\/\/unixwizardry.com\/wp-content\/uploads\/2019\/06\/120V-Mains-LED-Circuit_schem-300x141.jpg\" alt=\"\" width=\"300\" height=\"141\" srcset=\"https:\/\/unixwizardry.com\/wp-content\/uploads\/2019\/06\/120V-Mains-LED-Circuit_schem-300x141.jpg 300w, https:\/\/unixwizardry.com\/wp-content\/uploads\/2019\/06\/120V-Mains-LED-Circuit_schem-768x360.jpg 768w, https:\/\/unixwizardry.com\/wp-content\/uploads\/2019\/06\/120V-Mains-LED-Circuit_schem-830x389.jpg 830w, https:\/\/unixwizardry.com\/wp-content\/uploads\/2019\/06\/120V-Mains-LED-Circuit_schem-230x108.jpg 230w, https:\/\/unixwizardry.com\/wp-content\/uploads\/2019\/06\/120V-Mains-LED-Circuit_schem-350x164.jpg 350w, https:\/\/unixwizardry.com\/wp-content\/uploads\/2019\/06\/120V-Mains-LED-Circuit_schem-480x225.jpg 480w, https:\/\/unixwizardry.com\/wp-content\/uploads\/2019\/06\/120V-Mains-LED-Circuit_schem.jpg 948w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><figcaption id=\"caption-attachment-513\" class=\"wp-caption-text\">Powering and LED from 120 volts AC house current.<\/figcaption><\/figure>\n","protected":false},"excerpt":{"rendered":"<p>So, if you look at my post about Node-RED experiments and my portable powered breadboard, you&#8217;ll notice that the &#8220;power&#8221; LED isn&#8217;t [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[40],"tags":[],"class_list":["post-512","post","type-post","status-publish","format-standard","hentry","category-electronics"],"_links":{"self":[{"href":"https:\/\/unixwizardry.com\/index.php\/wp-json\/wp\/v2\/posts\/512","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/unixwizardry.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/unixwizardry.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/unixwizardry.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/unixwizardry.com\/index.php\/wp-json\/wp\/v2\/comments?post=512"}],"version-history":[{"count":3,"href":"https:\/\/unixwizardry.com\/index.php\/wp-json\/wp\/v2\/posts\/512\/revisions"}],"predecessor-version":[{"id":524,"href":"https:\/\/unixwizardry.com\/index.php\/wp-json\/wp\/v2\/posts\/512\/revisions\/524"}],"wp:attachment":[{"href":"https:\/\/unixwizardry.com\/index.php\/wp-json\/wp\/v2\/media?parent=512"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/unixwizardry.com\/index.php\/wp-json\/wp\/v2\/categories?post=512"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/unixwizardry.com\/index.php\/wp-json\/wp\/v2\/tags?post=512"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}