{"id":8234,"date":"2013-08-10T11:06:57","date_gmt":"2013-08-10T18:06:57","guid":{"rendered":"http:\/\/rustybolt.info\/wordpress\/?p=8234"},"modified":"2013-08-30T00:49:31","modified_gmt":"2013-08-30T07:49:31","slug":"2013-08-10-very-low-power-joule-thief-update","status":"publish","type":"post","link":"https:\/\/rustybolt.info\/wordpress\/?p=8234","title":{"rendered":"2013-08-10 Very Low Power Joule Thief Update"},"content":{"rendered":"

\"DSC_0464S3\"<\/a>I blogged my experiments with this very low power JT back in April<\/strong><\/a>, and I connected it to a cheap ‘heavy duty’ AA cell and left it running for a month or two.\u00a0 I added updates to the end of that blog I made one mistake: I should have taped a post it note to the AA cell with the starting date and followup dates and measurements.<\/p>\n

As can be seen in the photo it’s still running – the LED is still lit – but the cell voltage is down to 0.9V.\u00a0 These ‘heavy duty’ cells have a lot less (about half – see here<\/a>) capacity than the alkaline cells, and the shorter run time and lower voltage seem to show this.\u00a0 This just makes it easier to do tests because I have to wait half as long for the cell to run down (grin).\u00a0 Thus I can say that the run time on an alkaline cell will be about twice the time it runs on a ‘heavy duty’ cell.<\/p>\n

On the right can be seen the 470k resistor with the tan colored 47 pF disk capacitor across it.\u00a0 This is the very high value resistor that throttles down the transistor’s base current to a very low value, causing the Joule Thief to run at much less than a milliamp through the LED, and greatly extending the AA cell’s life.\u00a0 The AA cell has to supply less than a milliamp, too, something around a third of a milliamp, if I remember correctly.<\/p>\n

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I blogged my experiments with this very low power JT back in April, and I connected it to a cheap ‘heavy duty’ AA cell and left it running for a month or two.\u00a0 I added updates to the end of that blog I made one mistake: I should have taped a post it note to <\/p>\n

(Read More…)<\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4],"tags":[],"class_list":["post-8234","post","type-post","status-publish","format-standard","hentry","category-joule-thief-smps-dc-dc"],"_links":{"self":[{"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/8234","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=8234"}],"version-history":[{"count":10,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/8234\/revisions"}],"predecessor-version":[{"id":8428,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/8234\/revisions\/8428"}],"wp:attachment":[{"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=8234"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=8234"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=8234"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}