{"id":805,"date":"2021-10-01T05:09:15","date_gmt":"2021-10-01T05:09:15","guid":{"rendered":"https:\/\/www.wehopower.com\/?post_type=news&#038;p=805"},"modified":"2026-08-31T14:11:09","modified_gmt":"2026-08-31T06:11:09","slug":"history-of-switch-mode-power-supplies-smps","status":"publish","type":"news","link":"https:\/\/www.wehopower.com\/ms\/news\/history-of-switch-mode-power-supplies-smps\/","title":{"rendered":"History Of Switch Mode Power Supplies (SMPS)"},"content":{"rendered":"<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_86 counter-hierarchy ez-toc-counter ez-toc-grey ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Jadual Kandungan<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Togol<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewbox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewbox=\"0 0 24 24\" version=\"1.2\" baseprofile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/www.wehopower.com\/ms\/news\/history-of-switch-mode-power-supplies-smps\/#Ower_Supplies_%E2%80%93_just_how_far_have_we_come\" >Ower Supplies &#8211; just how far have we come?<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/www.wehopower.com\/ms\/news\/history-of-switch-mode-power-supplies-smps\/#Technological_Advancement\" >Technological Advancement?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/www.wehopower.com\/ms\/news\/history-of-switch-mode-power-supplies-smps\/#Calculating_Power\" >Calculating Power<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/www.wehopower.com\/ms\/news\/history-of-switch-mode-power-supplies-smps\/#Cooling_Off_in_the_70s_and_80s\" >Cooling Off in the &#8217;70s and &#8217;80s?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/www.wehopower.com\/ms\/news\/history-of-switch-mode-power-supplies-smps\/#EU_Shakeup\" >EU Shakeup<\/a><\/li><\/ul><\/li><\/ul><\/nav><\/div>\n<h2><span class=\"ez-toc-section\" id=\"Ower_Supplies_%E2%80%93_just_how_far_have_we_come\"><\/span>Ower Supplies &#8211; just how far have we come?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><img fetchpriority=\"high\" decoding=\"async\" class=\"alignnone wp-image-809\" src=\"https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2021\/11\/History-Of-Switch-Mode-Power-Supplies-SMPS-scaled.jpg?quality=85&strip=all\" alt=\"History Of Switch Mode Power Supplies (SMPS)  title=\" width=\"800\" height=\"426\" history of switch mode power supplies title=\"\" srcset=\"https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2021\/11\/History-Of-Switch-Mode-Power-Supplies-SMPS-scaled.jpg?quality=85&strip=all 2560w, https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2021\/11\/History-Of-Switch-Mode-Power-Supplies-SMPS-300x160.jpg?quality=85&strip=all 300w, https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2021\/11\/History-Of-Switch-Mode-Power-Supplies-SMPS-1024x546.jpg?quality=85&strip=all 1024w, https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2021\/11\/History-Of-Switch-Mode-Power-Supplies-SMPS-768x409.jpg?quality=85&strip=all 768w, https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2021\/11\/History-Of-Switch-Mode-Power-Supplies-SMPS-1536x818.jpg?quality=85&strip=all 1536w, https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2021\/11\/History-Of-Switch-Mode-Power-Supplies-SMPS-2048x1091.jpg?quality=85&strip=all 2048w, https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2021\/11\/History-Of-Switch-Mode-Power-Supplies-SMPS-1568x836.jpg?quality=85&strip=all 1568w\" sizes=\"(max-width: 800px) 100vw, 800px\" \/><\/p>\n<p>I recently had lunch with a customer we\u2019ve worked with since the late 1990s. We\u2019ve seen a lot of change in that time and, as the main course arrived, we started talking about how power supply technology has advanced over the years. This has been most noticeable in the areas of efficiency and power density.<\/p>\n<p>The first-ever unit he designed using XP Power was a 3 x 5&#8243; 40W PSU. That might have been considered revolutionary at the time but when you consider that his most recent product used a 350W unit in the same space envelope, it becomes clear just how far we\u2019ve come.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Technological_Advancement\"><\/span>Technological Advancement?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>I\u2019ve done a little research on this following our working lunch and, as far as I can tell, the very first switch-mode power supplies were designed in 1958 by IBM. They were based on vacuum tube technology. Several patents were filed for a \u2018transistor oscillation\u2019 by General Motors Corporation around the same time.<\/p>\n<p>With this influx of technological advancement, designers were suddenly able to pick and choose from multiple components and multiple manufacturers, giving them an unprecedented number of options and potentially groundbreaking designs.<\/p>\n<p>The focus of this intensive period of development was the traditional linear regulator \u2013 the brightest minds were trying to figure out how they could replace the outdated transformer and resistance method of changing input voltage with a more efficient design.<\/p>\n<p>The idea they landed on used a transistor to chop the input voltage up with an average value less than the initial input (we have a fantastic store of technical articles here on the site if you\u2019d like a more detailed description of SMPS operation).<\/p>\n<p>With higher efficiency and fewer magnetic materials required, the new technology was smaller, lighter and generated less heat.<\/p>\n<p>As with modern inventions with those characteristics, this 1950s solution was hugely appealing to businesses in a range of sectors \u2013 from electronics to aerospace and communications to computing, there was a flood of early adopters each jockeying to make the best use of this new power supply technology.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Calculating_Power\"><\/span>Calculating Power<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Over the next few years, a flurry of patents and designs emerged &#8211; many of which we still use today. In 1972, Hewlett Packard used a switching power supply in its first pocket calculator. 1976 saw the first patent to use the term switch mode power supply (SMPS) filed.<\/p>\n<p>HP\u2019s calculator was really a computer \u2013 albeit in a slightly different format than we know it today. Back then, the original design weighed over 40lbs. The SMPS was used in the design to save both space and weight, marking the first step towards the ultra-slim and incredibly light computers, laptops and tablets we use today.<\/p>\n<p>Similarly, aerospace manufacturers considering how they could save weight and space also began looking towards custom switching power supplies to create much more efficient designs.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Cooling_Off_in_the_70s_and_80s\"><\/span>Cooling Off in the &#8217;70s and &#8217;80s?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>The 1970s was a busy decade once the initial breakthrough had been made and innovation continued at a very respectable pace. Several companies in UK, USA and Japan began to market standard power supply products.<\/p>\n<p>To this day, there are around a dozen companies who claim to have been the first to design and market a switch-mode power supply successfully \u2013 so we won\u2019t go there!<\/p>\n<p>The electronics magazines of the era featured articles and adverts for SMPS. The leader at that time was Boschert Inc., an American corporation that started in California. It replaced linear printer power supplies with switch mode designs.<\/p>\n<p>This company grew to over 1000 people, with a vast product range of open frame, cased and modular power supplies. It was eventually acquired by Computer Products Inc. in the mid-80s.<\/p>\n<p>Apple Computers first introduced a switch-mode power supply into the Apple II computer in the 1970s. This small, highly efficient technology meant Apple could build a smaller, lighter computer without a cooling fan.<\/p>\n<p>This type of convection-cooled design was unique at the time. The technology had taken on a life of its own and was used in dozens of consumer applications. IBM PC power supplies also made the move to switch mode, albeit with cooling fans similar to the ones they use in ATX-style power supplies today.<\/p>\n<p>In the late 1980s and early part of the 1990s, we were stunned when the industry standard 3 x 5\u201d power supplies became available with an auto-ranging input that sensed whether it was connected to 120VAC or 230VAC and adjusted accordingly. These products had powers of 25 \u2013 40W, or 1.66 to 2.66W\/In2<\/p>\n<h3><span class=\"ez-toc-section\" id=\"EU_Shakeup\"><\/span>EU Shakeup<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>As more and more companies entered the market, some loose industry standards appeared around common sizes like 3&#215;5\u201d. Power densities began to improve as advances in magnetics, switching transistors and controller ICs progressed. These changes offered higher efficiencies and made better power densities possible.<\/p>","protected":false},"excerpt":{"rendered":"<p>Ower Supplies &#8211; just how far have we come? I recently had lunch with a customer we\u2019ve worked with since the late 1990s. We\u2019ve seen a lot of change in that time and, as the main course arrived, we started talking about how power supply technology has advanced over the years. This has been most&hellip; <a class=\"more-link\" href=\"https:\/\/www.wehopower.com\/ms\/news\/history-of-switch-mode-power-supplies-smps\/\">Teruskan membaca <span class=\"screen-reader-text\">History Of Switch Mode Power Supplies (SMPS)<\/span><\/a><\/p>","protected":false},"author":1,"featured_media":809,"parent":0,"menu_order":375,"comment_status":"open","ping_status":"open","template":"","format":"standard","meta":{"_acf_changed":false,"_joinchat":[],"footnotes":""},"news_category":[149,148],"class_list":["post-805","news","type-news","status-publish","format-standard","has-post-thumbnail","hentry","news_category-blog","news_category-industry-news","entry"],"acf":[],"post_mailing_queue_ids":[],"_links":{"self":[{"href":"https:\/\/www.wehopower.com\/ms\/wp-json\/wp\/v2\/news\/805","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.wehopower.com\/ms\/wp-json\/wp\/v2\/news"}],"about":[{"href":"https:\/\/www.wehopower.com\/ms\/wp-json\/wp\/v2\/types\/news"}],"author":[{"embeddable":true,"href":"https:\/\/www.wehopower.com\/ms\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.wehopower.com\/ms\/wp-json\/wp\/v2\/comments?post=805"}],"version-history":[{"count":0,"href":"https:\/\/www.wehopower.com\/ms\/wp-json\/wp\/v2\/news\/805\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.wehopower.com\/ms\/wp-json\/wp\/v2\/media\/809"}],"wp:attachment":[{"href":"https:\/\/www.wehopower.com\/ms\/wp-json\/wp\/v2\/media?parent=805"}],"wp:term":[{"taxonomy":"news_category","embeddable":true,"href":"https:\/\/www.wehopower.com\/ms\/wp-json\/wp\/v2\/news_category?post=805"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}