{"id":5342,"date":"2012-12-16T19:40:57","date_gmt":"2012-12-17T03:40:57","guid":{"rendered":"http:\/\/rustybolt.info\/wordpress\/?p=5342"},"modified":"2013-01-09T05:22:23","modified_gmt":"2013-01-09T13:22:23","slug":"2012-12-16-quick-and-cheap-joule-thief-light","status":"publish","type":"post","link":"https:\/\/rustybolt.info\/wordpress\/?p=5342","title":{"rendered":"2012-12-16 Quick And Cheap Joule Thief Light"},"content":{"rendered":"

\"\"<\/a>I blogged a similar light recently<\/a>, but I didn’t get a good closeup picture of the parts laid out on the back of the AAA cell holder.\u00a0 This time I got a good photo of it before I coated it with clear silicone sealant (I did get a good closeup, it’s in the linnk above).\u00a0 I did not include an on\/off switch because I figure these are made for a single use, and will be kept around in some drawer and possibly disposed of soon after use.\u00a0 And I’m too cheap to spend $2 or more (USD) for a switch that actually costs more than the rest of the light.\u00a0 I just cut a small piece of heavy paper or cardboard from a cereal box or whatever and stuck it between the battery and the contact.\u00a0 When I need the light, I just pull out the paper.<\/p>\n

Which brings me to the cost of the parts.\u00a0 The LED was somewhat expensive, since it’s a Nichia that I bought a long time ago and probably cost a dollar.\u00a0 Today anyone can get 9 of them in a cheapo flashlight that costs $2.00 (See Note).\u00a0 The PN2222A transistor was less than 5 cents or five dollars for a bag of 100.\u00a0 The resistor was pulled from a board, but they’re about 2 cents or $2 per hundred.\u00a0 The toroid core was from Surplussales.com and cost about $.25, (ICH T231212T<\/a>) and the wire was 30 AWG and cost very little, probably a few cents, since a quarter pound reel was about $15 but there are over a thousand feet of wire on it, and I used only about a foot.<\/p>\n

Back to waiting for the silicone seal to dry so I won’t get sticky fingers from handling the light.\u00a0 \ud83d\ude09<\/p>\n

Note:<\/strong> Some might wonder why I would pull apart a good flashlight (torch) with 9 LEDs to make one with 1 LED.\u00a0 Well, the 9 LED light gobbles three AAA cells at a time, and doesn’t run very long on a fresh set of 3.\u00a0 I have bought several of the Fenix LD01 flashlights, and they put out so much more light and use only a single AAA cell, and they’re so small I have one of them on my keychain.\u00a0 So I will not use one of these cheapo flashlights, I just take out the LEDs and scrap the rest.\u00a0 I tried using one of them for some other project, but after a year or so the plastic case became sticky and gooey, and melted into whatever it touched.\u00a0 It was making a mess, so I don’t leave them around anymore.\u00a0 Besides, I now have a single cheapo light that fits just about anywhere and runs off a single AAA cell.\u00a0 And I’m proud to say I made it myself.<\/p>\n","protected":false},"excerpt":{"rendered":"

I blogged a similar light recently, but I didn’t get a good closeup picture of the parts laid out on the back of the AAA cell holder.\u00a0 This time I got a good photo of it before I coated it with clear silicone sealant (I did get a good closeup, it’s in the linnk above).\u00a0 <\/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-5342","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\/5342","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=5342"}],"version-history":[{"count":19,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/5342\/revisions"}],"predecessor-version":[{"id":5724,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/5342\/revisions\/5724"}],"wp:attachment":[{"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=5342"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=5342"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=5342"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}