{"id":10944,"date":"2015-12-16T09:21:40","date_gmt":"2015-12-16T17:21:40","guid":{"rendered":"http:\/\/rustybolt.info\/wordpress\/?p=10944"},"modified":"2015-12-21T00:17:57","modified_gmt":"2015-12-21T08:17:57","slug":"2015-12-16-jfet-joule-thief","status":"publish","type":"post","link":"https:\/\/rustybolt.info\/wordpress\/?p=10944","title":{"rendered":"2015-12-16 JFET Joule Thief"},"content":{"rendered":"<p>I captured this off a video and tried to make it a bit more readable.\u00a0 I think it was from Sanjev.<\/p>\n<p><a href=\"http:\/\/rustybolt.info\/wordpress\/wp-content\/uploads\/2015\/12\/wpid-wp-1450286112662.jpeg\"><img decoding=\"async\" title=\"wp-1450286112662\" class=\"alignnone size-full\"  alt=\"image\" src=\"http:\/\/rustybolt.info\/wordpress\/wp-content\/uploads\/2015\/12\/wpid-wp-1450286112662.jpeg\" \/><\/a><\/p>\n<p>I built it and it does work at 40 millivolts.&nbsp; The 2SK170 JFETs are not common, and may be difficult to obtain.&nbsp; Other JFETs can be used, but I haven&#8217;t tried them.&nbsp; I wrote about this in the updates in a previous blog.  The reason there are so many turns on the feedback winding is the input voltage is very low, and the JFET&#8217;s gate is controlled by voltage, not current like a regular BJT transistor.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>I captured this off a video and tried to make it a bit more readable.\u00a0 I think it was from Sanjev. I built it and it does work at 40 millivolts.&nbsp; The 2SK170 JFETs are not common, and may be difficult to obtain.&nbsp; Other JFETs can be used, but I haven&#8217;t tried them.&nbsp; I wrote<a href=\"https:\/\/rustybolt.info\/wordpress\/?p=10944\"> <\/p>\n<p> (Read More&#8230;)<\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[81,141,4],"tags":[],"class_list":["post-10944","post","type-post","status-publish","format-standard","hentry","category-field-effect-transistors-fets","category-free-energy","category-joule-thief-smps-dc-dc"],"_links":{"self":[{"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/10944","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=10944"}],"version-history":[{"count":2,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/10944\/revisions"}],"predecessor-version":[{"id":10946,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/10944\/revisions\/10946"}],"wp:attachment":[{"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=10944"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=10944"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=10944"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}