{"id":295,"date":"2020-08-18T19:23:47","date_gmt":"2020-08-18T20:23:47","guid":{"rendered":"http:\/\/www.linux-tutorial.info\/?page_id=77"},"modified":"2020-08-22T19:26:40","modified_gmt":"2020-08-22T20:26:40","slug":"this-is-the-page-title-toplevel-130","status":"publish","type":"page","link":"http:\/\/www.linux-tutorial.info\/?page_id=295","title":{"rendered":"Uninterruptable Power Supplies"},"content":{"rendered":"\n<title>Uninterruptable Power Supplies<\/title>\n<p>\nThe first thing I want to address\nhere is the concept of uninterruptable power. If you take that term literally,\na power supply that goes out at all has been interrupted. In that case, many\n<glossary>UPS<\/glossary> are not correctly named because there is a brief moment\n(ca. 30 milliseconds) between the time the computer notices the power has gone\nout and the battery kicks in. This time is too short for the computer to notice,\nbut it is there. (Normally, power must be out for at least 300 milliseconds\nbefore the computer will notice.) As a result, most UPS should be referred to as\nstand-by power supply (SPS) because they switch to the battery when the primary\nsupply shuts off. Because Underwriters Laboratories uses UPS to describe both,\nthat&#8217;s what I will do here.\n<\/p>\n<p>\nThe basic <glossary>UPS<\/glossary>\nprovides limited power conditioning (keeping the voltage within a specific\nrange) but no protection against surges and spikes. This is useful if the power\ngoes out but doesn&#8217;t protect you if the voltage suddenly jumps (such as the\nresult of a lightning strike). A <em>double-conversion <\/em>model provides the\npower when the main power fails and also provides protection against surges by\nfirst passing the power through the batteries. Although this does provide\nprotection, it is less efficient because power is constantly drawn from the\nbattery.\n<\/p>\n<p>\nAlthough no <glossary>UPS<\/glossary>\nvendor directly supports Linux, there are several sources for programs that can\ntake advantage of existing UPSs. The best place to start is the UPS\n<glossary>HOWTO<\/glossary>.\n<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Uninterruptable Power Supplies The first thing I want to address here is the concept of uninterruptable power. If you take that term literally, a power supply that goes out at all has been interrupted. In that case, many UPS are &hellip; <a href=\"http:\/\/www.linux-tutorial.info\/?page_id=295\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-295","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"http:\/\/www.linux-tutorial.info\/index.php?rest_route=\/wp\/v2\/pages\/295","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.linux-tutorial.info\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"http:\/\/www.linux-tutorial.info\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"http:\/\/www.linux-tutorial.info\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.linux-tutorial.info\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=295"}],"version-history":[{"count":1,"href":"http:\/\/www.linux-tutorial.info\/index.php?rest_route=\/wp\/v2\/pages\/295\/revisions"}],"predecessor-version":[{"id":770,"href":"http:\/\/www.linux-tutorial.info\/index.php?rest_route=\/wp\/v2\/pages\/295\/revisions\/770"}],"wp:attachment":[{"href":"http:\/\/www.linux-tutorial.info\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=295"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}