{"id":9722,"date":"2017-12-05T01:57:27","date_gmt":"2017-12-04T20:27:27","guid":{"rendered":"https:\/\/www.electronicsforu.com\/?p=9722"},"modified":"2021-09-01T15:46:45","modified_gmt":"2021-09-01T10:16:45","slug":"voltage-based-controller-switches","status":"publish","type":"post","link":"https:\/\/www.electronicsforu.com\/electronics-projects\/hardware-diy\/voltage-based-controller-switches","title":{"rendered":"Voltage Based Controller For Switches"},"content":{"rendered":"<p><img loading=\"lazy\" decoding=\"async\" class=\"alignright size-thumbnail wp-image-33665\" src=\"https:\/\/www.electronicsforu.com\/wp-contents\/uploads\/2014\/01\/scdwivedi-150x150.png\" alt=\"\" width=\"150\" height=\"150\" \/>Here\u2019s a simple voltage based controller circuit for controlling four switches from a distance through just a pair of wires.<\/p>\n<h2>Voltage based controller circuit<\/h2>\n<p>In the circuit, the inverting inputs (pin 2) of operational amplifiers IC1 through IC4 are set to reference voltages of +12V, +9V, +6V, and +3V, respectively, through a chain of four 1k resistors (R1 through R4).<\/p>\n<figure id=\"attachment_9723\" aria-describedby=\"caption-attachment-9723\" style=\"width: 966px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/www.electronicsforu.com\/wp-contents\/uploads\/2016\/03\/55F_july_09_efy.png\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-9723 size-full\" src=\"\/\/electronicsforu.com\/wp-contents\/uploads\/2016\/03\/55F_july_09_efy.png\" alt=\"Voltage Based Controller Circuit\" width=\"966\" height=\"814\" srcset=\"https:\/\/www.electronicsforu.com\/wp-contents\/uploads\/2016\/03\/55F_july_09_efy.png 966w, https:\/\/www.electronicsforu.com\/wp-contents\/uploads\/2016\/03\/55F_july_09_efy-500x421.png 500w, https:\/\/www.electronicsforu.com\/wp-contents\/uploads\/2016\/03\/55F_july_09_efy-696x586.png 696w, https:\/\/www.electronicsforu.com\/wp-contents\/uploads\/2016\/03\/55F_july_09_efy-498x420.png 498w\" sizes=\"auto, (max-width: 966px) 100vw, 966px\" \/><\/a><figcaption id=\"caption-attachment-9723\" class=\"wp-caption-text\">Voltage Based Controller Circuit<\/figcaption><\/figure>\n<p>The reference voltage (Vref) can be simply calculated by the following relationship: For example, reference voltage Vref3 is calculated as follows: The non-inverting inputs (pin 3) of the four <a href=\"https:\/\/www.electronicsforu.com\/resources\/learn-electronics\/op-amp-basics-operational-amplifier\">op-amps<\/a> ( IC1 through IC4) are tied together and connected to a pair of wires that provide +3V to +12V input voltage for controlling the switches.<\/p>\n<pre>VREF= Total applied voltage\u00d7Resistance\r\n      across reference voltage\r\n       ---------------------\r\n         Total resistance<\/pre>\n<p>For example, reference voltage VREF3 is calculated as follows:<\/p>\n<pre>V REF3 = 12V\u00d7(R3+R4) = 12V\u00d72k = 6V\r\n         -----------   -----\r\n         R1+R2+R3+R4     4k<\/pre>\n<p>The non-inverting inputs (pin 3) of the four op-amps ( IC1 through IC4) are tied together and connected to a pair of wires that provide +3V to +12V in input voltage for controlling the switches.<\/p>\n<h3>Circuit operation<\/h3>\n<p>Four 12V, 200-ohm, single <a href=\"https:\/\/www.quora.com\/What-is-changeover-relay\" target=\"_blank\" rel=\"noopener\">changeover relays<\/a> are connected to four BC548 relay driver transistors (T1 through T4) via resistors R5 through R8, respectively. These relays energize depending on the voltage present at the controlling voltage input terminal; for example, relay RL4 energizes when controlling voltage input of +3V is available at non-inverting pin 3 of IC4. Four electrical equipment can be connected to the terminals of the relays through the 220V AC, 50Hz mains.<\/p>\n<hr \/>\n<p>The article was first published in July 2006 and has recently been updated.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Here\u2019s a simple voltage based controller circuit for controlling four switches from a distance through just a pair of wires. Voltage based controller circuit In the circuit, the inverting inputs (pin 2) of operational amplifiers IC1 through IC4 are set to reference voltages of +12V, +9V, +6V, and +3V, respectively, through a chain of four [&hellip;]<\/p>\n","protected":false},"author":13,"featured_media":9724,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[23,22,6071],"tags":[130,114,111,110,113],"class_list":{"0":"post-9722","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-hardware-diy","8":"category-electronics-projects","9":"category-intermediate-projects","10":"tag-digital-electronics-projects","11":"tag-ece-projects","12":"tag-electrical-projects","13":"tag-electronics-projects","14":"tag-mini-projects"},"_links":{"self":[{"href":"https:\/\/www.electronicsforu.com\/wp-json\/wp\/v2\/posts\/9722","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.electronicsforu.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.electronicsforu.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.electronicsforu.com\/wp-json\/wp\/v2\/users\/13"}],"replies":[{"embeddable":true,"href":"https:\/\/www.electronicsforu.com\/wp-json\/wp\/v2\/comments?post=9722"}],"version-history":[{"count":0,"href":"https:\/\/www.electronicsforu.com\/wp-json\/wp\/v2\/posts\/9722\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.electronicsforu.com\/wp-json\/wp\/v2\/media\/9724"}],"wp:attachment":[{"href":"https:\/\/www.electronicsforu.com\/wp-json\/wp\/v2\/media?parent=9722"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.electronicsforu.com\/wp-json\/wp\/v2\/categories?post=9722"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.electronicsforu.com\/wp-json\/wp\/v2\/tags?post=9722"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}