{"id":6376,"date":"2013-02-20T22:25:03","date_gmt":"2013-02-21T06:25:03","guid":{"rendered":"http:\/\/rustybolt.info\/wordpress\/?p=6376"},"modified":"2013-02-27T07:37:29","modified_gmt":"2013-02-27T15:37:29","slug":"2013-02-20-tbd","status":"publish","type":"post","link":"https:\/\/rustybolt.info\/wordpress\/?p=6376","title":{"rendered":"2013-02-20 EnCAPsulated ‘Joule Thief’ V Booster"},"content":{"rendered":"

\"\"<\/a>There are many other uses for common household items, or even stuff that would otherwise go to the trash or recycling.\u00a0 In this case, I built a two transistor “Joule Thief” V Booster on a small perf board, put it inside of a soda bottle cap along with two screws and encapsulated it in epoxy – that’s why it’s enCAPsulated.\u00a0 The photo shows the choke with a single winding, labeled ‘104’ for 100 microhenrys.\u00a0 The epoxy has turned a bit dark with age.\u00a0 I use the term ‘Joule Thief’ but it’s not a true Joule Thief.<\/p>\n

This circuit uses two transistors because I built it back in the early 2000s (might have been\u00a0 Oct 2003) before I had learned how to get a single transistor to put out enough current to light the LED to full brightness, or about 20 milliamps.\u00a0 Instead, I used the conventional two transistor circuit and a choke with a single low resistance winding.\u00a0 I had only had limited experience with winding toroids, and I didn’t have enough experience to know what kind of core to use or how to wind it with heavier low resistance wire.\u00a0 I remember the chokes cost about a dollar apiece.\u00a0 Nowadays, I can wind a toroid core with two short lengths of telephone wire for about 12 cents.<\/p>\n

The two screws were to anchor it down in an outside environment; the epoxy was for protection against the weather.\u00a0 Later I found that the transistor has to be capable of handling very high current at low voltage, and that meant the transistor has to be chosen for that purpose – many transistors are not capable.\u00a0 The wisdom of Joule Thief building came to me after a few years, and I learned from experimenting and experience that if I wanted to see good Joule Thief performance, I had to understand how they worked and what to use for components.\u00a0 I guess I could call it the Care and Feeding of Joule Thiefs. \u00a0 I thought about authoring a book, which would consist mostly of the\u00a0 blogs I had written about Joule Thiefs in my late watsonseblog.\u00a0 But it went away, thanks to the BOFHs at blogger.<\/p>\n

But back to this circuit.\u00a0 The LED is very bright and can be seen even though the camera’s flash is very bright.\u00a0 I built several of these same circuits, and put them in Velamints tins (a\u00a0 miniature Altoids tin).\u00a0 One of them can be seen in my blog here<\/a>.<\/p>\n

Back to experimenting…<\/p>\n","protected":false},"excerpt":{"rendered":"

There are many other uses for common household items, or even stuff that would otherwise go to the trash or recycling.\u00a0 In this case, I built a two transistor “Joule Thief” V Booster on a small perf board, put it inside of a soda bottle cap along with two screws and encapsulated it in epoxy <\/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":[4,1],"tags":[],"class_list":["post-6376","post","type-post","status-publish","format-standard","hentry","category-joule-thief-smps-dc-dc","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/6376","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=6376"}],"version-history":[{"count":14,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/6376\/revisions"}],"predecessor-version":[{"id":6416,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/6376\/revisions\/6416"}],"wp:attachment":[{"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=6376"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=6376"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=6376"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}