{"id":1217,"date":"2015-06-01T03:07:32","date_gmt":"2015-06-01T03:07:32","guid":{"rendered":"http:\/\/www.blog.exrockets.com\/blog\/?p=1217"},"modified":"2018-03-15T04:41:09","modified_gmt":"2018-03-15T04:41:09","slug":"pwm-power-regulator","status":"publish","type":"post","link":"http:\/\/www.blog.exrockets.com\/blog\/pwm-power-regulator\/","title":{"rendered":"PWM POWER REGULATOR"},"content":{"rendered":"<p><a href=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2015\/06\/PWM.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-1219\" src=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2015\/06\/PWM.jpg\" alt=\"PWM\" width=\"1800\" height=\"1351\" srcset=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2015\/06\/PWM.jpg 1800w, http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2015\/06\/PWM-300x225.jpg 300w, http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2015\/06\/PWM-1024x769.jpg 1024w\" sizes=\"auto, (max-width: 1800px) 100vw, 1800px\" \/><\/a><\/p>\n<p>In order to synthesize chlorates and perchlorates in the home lab it is always good to have a way to regulate the current flowing through the electrolyte. Because the load is purely resistive the simplest solution is a small PWM (Pulse Width Modulation) regulator. So I decided to make my own.<\/p>\n<p>The schematic is very simple. It could be divided in two parts:<\/p>\n<p><a href=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2015\/06\/pwm_sch.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-1220\" src=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2015\/06\/pwm_sch.png\" alt=\"pwm_sch\" width=\"2645\" height=\"1778\" \/><\/a><\/p>\n<ol>\n<li>PWM generator<\/li>\n<\/ol>\n<ul>\n<li>The MCU generates the pulses, which greatly simplifies the circuit.<\/li>\n<li>There are two buttons (UP and DOWN) respectively to increase and decrease the power.<\/li>\n<li>The LED is very crude indication of the pulse width \u2013 the faster it blinks the greater the duty cycle. If the LED is solid on then the duty cycle is 100% and if it is off then the duty cycle is 0%<\/li>\n<li>MCU power supply \u2013 this is a 3.3v LDO regulator \u2013 so depending on the MOSFET you can use power supply ranging from 3.7v to 25v.<\/li>\n<li>The switching frequency is 32 kHz and the pulse width is divided in 256 steps, including full ON and full OFF.<\/li>\n<\/ul>\n<ol start=\"2\">\n<li>Power MOSFET<\/li>\n<\/ol>\n<ul>\n<li>The driver for the MOSFET transistor is the common 2N3904.<\/li>\n<li>The power MOSFET transistor could be any suitable N-channel MOSFET.<\/li>\n<li>The power traces on this PCB are calculated for about 5-6 amps \u2013 if higher currents are needed then a simple bypass with a suitable wire will do.<\/li>\n<\/ul>\n<p>Nowadays the hobby PCB suppliers offer very affordable prices and I ordered few of the following PCBs that I prepared.<\/p>\n<p><a href=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2015\/06\/PCB_TOP.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone  wp-image-1222\" src=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2015\/06\/PCB_TOP.jpg\" alt=\"PCB_TOP\" width=\"264\" height=\"393\" \/><\/a><a href=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2015\/06\/PCB_BOT.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone  wp-image-1221\" src=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2015\/06\/PCB_BOT.jpg\" alt=\"PCB_BOT\" width=\"264\" height=\"394\" \/><\/a><\/p>\n<p>Finally a short video with a car bulb for demonstration.<\/p>\n<p><iframe loading=\"lazy\" src=\"https:\/\/www.youtube.com\/embed\/oZ6Xe8OIj7c\" width=\"560\" height=\"315\" frameborder=\"0\" allowfullscreen=\"allowfullscreen\"><\/iframe><\/p>\n<p>&nbsp;<\/p>\n<p><a href=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2015\/06\/PWM-CADCAM.zip\">PCB MANUFACTURING FILES (GERBER FORMAT)<\/a><br \/>\n<a href=\"http:\/\/www.blog.exrockets.com\/blog\/wp-content\/uploads\/2015\/06\/PWM.zip\">MCU FIRMWARE (HEX FORMAT)<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>In order to synthesize chlorates and perchlorates in the home lab it is always good to have a way to regulate the current flowing through the electrolyte. Because the load is purely resistive the simplest solution is a small PWM (Pulse Width Modulation) regulator. So I decided to make my own. The schematic is very [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"gallery","meta":{"footnotes":""},"categories":[9],"tags":[],"class_list":["post-1217","post","type-post","status-publish","format-gallery","hentry","category-electronics","post_format-post-format-gallery"],"_links":{"self":[{"href":"http:\/\/www.blog.exrockets.com\/blog\/wp-json\/wp\/v2\/posts\/1217","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.blog.exrockets.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.blog.exrockets.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.blog.exrockets.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.blog.exrockets.com\/blog\/wp-json\/wp\/v2\/comments?post=1217"}],"version-history":[{"count":5,"href":"http:\/\/www.blog.exrockets.com\/blog\/wp-json\/wp\/v2\/posts\/1217\/revisions"}],"predecessor-version":[{"id":1229,"href":"http:\/\/www.blog.exrockets.com\/blog\/wp-json\/wp\/v2\/posts\/1217\/revisions\/1229"}],"wp:attachment":[{"href":"http:\/\/www.blog.exrockets.com\/blog\/wp-json\/wp\/v2\/media?parent=1217"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.blog.exrockets.com\/blog\/wp-json\/wp\/v2\/categories?post=1217"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.blog.exrockets.com\/blog\/wp-json\/wp\/v2\/tags?post=1217"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}