{"id":352,"date":"2014-11-21T00:44:28","date_gmt":"2014-11-21T04:44:28","guid":{"rendered":"http:\/\/jimlund.org\/blog\/?p=348"},"modified":"2015-02-18T16:13:06","modified_gmt":"2015-02-18T22:13:06","slug":"modding-a-sunbeam-heating-pad","status":"publish","type":"post","link":"https:\/\/jimlund.org\/blog\/?p=352","title":{"rendered":"Modding a Sunbeam heating pad"},"content":{"rendered":"<p>I bought a Sunbeam heating pad. It has low\/med\/high settings, and turns off after two hours.<br \/>\n<img decoding=\"async\" src=\"pics\/sunbeam.jpg\" alt=\"heating pad\" \/><\/p>\n<p>The back of the controller says &#8216;Sunbeam SLA103&#8217;.<\/p>\n<p>I wanted to eliminate the shutoff, I&#8217;m using it to heat my fermentation bucket.<\/p>\n<p><!--more--><\/p>\n<p>I found good information in this instructable, <a href=\"http:\/\/www.instructables.com\/id\/Disabling-Auto-Off-on-a-Sunbeam-Health-at-Home-hea\/\">Disabling Auto-Off on a Sunbeam Health at Home heating pad<\/a>.<\/p>\n<p>I opened the controller up, and the circuit board was similar, but some of the components had moved, and the microcontroller was different.<\/p>\n<p><img decoding=\"async\" src=\"pics\/Sunbeam1.jpg\" alt=\"circuit board\" \/><\/p>\n<p>Microcontroller is a NXP Semiconductors HEF4060BF. I figured this is similar to the CD4060, and found this datasheet, <a href=\"pics\/74HC4060D-Philips.pdf\">74HC4060D Philips\/NXP<\/a>.<\/p>\n<p><img decoding=\"async\" src=\"pics\/Sunbeam3.jpg\" alt=\"microcontroller\" \/><br \/>\n<img decoding=\"async\" src=\"pics\/Sunbeam2.jpg\" alt=\"closeup\" \/><\/p>\n<p>Looking at the circuit board, there is a capacitor (C3, 480nF) between pins 12 and 16 which makes sense if pin 12 is the master reset. Pin 3, Q13, is connected to the triac (T1). Pins 9 and 19 have a capacitor (C2) and resistor (R7), and this likely makes up the RC timing circuit. So this chip is a 4060.<\/p>\n<p>As you can see on the circuit board, I removed C3. I replaced it with a 10K ohm resistor, and now the heating pad stays on indefinitely.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>I bought a Sunbeam heating pad. It has low\/med\/high settings, and turns off after two hours. The back of the controller says &#8216;Sunbeam SLA103&#8217;. I wanted to eliminate the shutoff, I&#8217;m using it to heat my fermentation bucket.<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7,8],"tags":[],"class_list":["post-352","post","type-post","status-publish","format-standard","hentry","category-hobbies","category-howto"],"_links":{"self":[{"href":"https:\/\/jimlund.org\/blog\/index.php?rest_route=\/wp\/v2\/posts\/352","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/jimlund.org\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/jimlund.org\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/jimlund.org\/blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/jimlund.org\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=352"}],"version-history":[{"count":1,"href":"https:\/\/jimlund.org\/blog\/index.php?rest_route=\/wp\/v2\/posts\/352\/revisions"}],"predecessor-version":[{"id":362,"href":"https:\/\/jimlund.org\/blog\/index.php?rest_route=\/wp\/v2\/posts\/352\/revisions\/362"}],"wp:attachment":[{"href":"https:\/\/jimlund.org\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=352"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/jimlund.org\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=352"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/jimlund.org\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=352"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}