{"id":3725,"date":"2012-08-17T09:07:47","date_gmt":"2012-08-17T16:07:47","guid":{"rendered":"http:\/\/rustybolt.info\/wordpress\/?p=3725"},"modified":"2012-08-19T04:32:58","modified_gmt":"2012-08-19T11:32:58","slug":"2012-08-17","status":"publish","type":"post","link":"https:\/\/rustybolt.info\/wordpress\/?p=3725","title":{"rendered":"2012-08-17 Joule Thief Plus 22 nF Capacitor"},"content":{"rendered":"<p><a href=\"http:\/\/rustybolt.info\/wordpress\/?attachment_id=3738\" rel=\"attachment wp-att-3738\"><img loading=\"lazy\" decoding=\"async\" class=\"alignright size-medium wp-image-3738\" title=\"JouleThief+22nFcap\" src=\"http:\/\/rustybolt.info\/wordpress\/wp-content\/uploads\/2012\/08\/JouleThief+22nFcap-300x160.jpg\" alt=\"\" width=\"300\" height=\"160\" srcset=\"https:\/\/rustybolt.info\/wordpress\/wp-content\/uploads\/2012\/08\/JouleThief+22nFcap-300x160.jpg 300w, https:\/\/rustybolt.info\/wordpress\/wp-content\/uploads\/2012\/08\/JouleThief+22nFcap.jpg 800w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a>I received a Google Alert with a <a href=\"http:\/\/www.totseans.com\/bbs\/threads\/23430-The-Joule-Thief-Circuit\">link to a forum<\/a> in which the poster declared that adding a 22 nF capacitor to the conventional JT will increase its brightness.\u00a0 I&#8217;ve read this claim previously and I tried the circuit (see attached pic) and I found that the LED went from\u00a0 bright without the capacitor to dim when I added the capacitor.\u00a0 But just to triple-check, or more like quintuple- or sextuple-check, I again within the last hour soldered a Joule Thief together, and then connected the 22 nF capacitor.\u00a0 Again, when the capacitor was not connected, the LED was bright.\u00a0 But when I added the capacitor, the LED again went dim.\u00a0 The difference was dramatic: it wasn&#8217;t just a little bit dimmer, it was much, much dimmer.\u00a0 The LED was useless for illumination with the capacitor connected.<\/p>\n<p>I&#8217;m not sure where these people get this spurious information.\u00a0 The poster claimed, well, you can read it in the link or in the schematic.\u00a0 I don&#8217;t think anyone who has made this claim has ever put the circuit together.\u00a0 If they had done so, they would have seen how really bad this circuit performs.\u00a0 The poster said that he had drawn the circuit in Multisim.\u00a0 If he simulated the circuit and got the results he made in his claim, then I would say that his software is unable to simulate the actual circuit, and it&#8217;s time to get rid of it and instead do it in the Real World.<\/p>\n<p>One thing is for certain.\u00a0 If he or she replaces the 2N3904 with a 2N4401, the LED will get brighter: the LED current will go from under 10 mA to closer to 20 mA.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>I received a Google Alert with a link to a forum in which the poster declared that adding a 22 nF capacitor to the conventional JT will increase its brightness.\u00a0 I&#8217;ve read this claim previously and I tried the circuit (see attached pic) and I found that the LED went from\u00a0 bright without the capacitor<a href=\"https:\/\/rustybolt.info\/wordpress\/?p=3725\"> <\/p>\n<p> (Read More&#8230;)<\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[75,4],"tags":[],"class_list":["post-3725","post","type-post","status-publish","format-standard","hentry","category-capacitors","category-joule-thief-smps-dc-dc"],"_links":{"self":[{"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/3725","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=3725"}],"version-history":[{"count":8,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/3725\/revisions"}],"predecessor-version":[{"id":3736,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/3725\/revisions\/3736"}],"wp:attachment":[{"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3725"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3725"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3725"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}