{"id":11031,"date":"2020-04-25T15:58:07","date_gmt":"2020-04-25T14:58:07","guid":{"rendered":"https:\/\/myworldofit.net\/?p=11031"},"modified":"2026-03-22T16:47:26","modified_gmt":"2026-03-22T16:47:26","slug":"mcp1700-wrong-voltage-without-capacitors","status":"publish","type":"post","link":"https:\/\/myworldofit.net\/?p=11031","title":{"rendered":"MCP1700, wrong voltage without capacitors"},"content":{"rendered":"<p>In looking to keep occupied with the current pandemic going on I&#8217;ve taken my Microelectronics projects to a new level and have over the past few weeks kicked out a series of soil moisture sensors which are powered by battery (18650) with a small solar panel keeping them topped up.<\/p>\n<p>As the battery charges\/discharges the voltage changes and moves outside of the acceptable ranges for the little ESP32 MCU, here a load drop out voltage regulator like the <a href=\"http:\/\/ww1.microchip.com\/downloads\/en\/DeviceDoc\/20001826D.pdf\">Microchip MCP1700<\/a> comes into play by ensuring that the controller is fed the right voltage all the time. In researching this project I&#8217;ve come across a fair few articles which mention the regulator is only &#8216;stable&#8217; or &#8216;the supply is smoothed out&#8217; with a set of capacitors in line. Just to test that out I hooked my multimeter up to the MCP1700 without the capacitors and lone behold the wrong voltage is being kicked out. Put the capacitors in line and everything works as expected.<\/p>\n<p>ngg_shortcode_0_placeholderThe article I followed when putting my final projects together is at these links:<\/p>\n<ul>\n<li><a href=\"https:\/\/randomnerdtutorials.com\/power-esp32-esp8266-solar-panels-battery-level-monitoring\">https:\/\/randomnerdtutorials.com\/power-esp32-esp8266-solar-panels-battery-level-monitoring<\/a><\/li>\n<li><a href=\"https:\/\/randomnerdtutorials.com\/esp8266-voltage-regulator-lipo-and-li-ion-batteries\">https:\/\/randomnerdtutorials.com\/esp8266-voltage-regulator-lipo-and-li-ion-batteries<\/a><\/li>\n<\/ul>\n<p>There does appear to be a discrepancy (1uF vs 100nF) between the capacity of the capacitors in the datasheet and the article (and indeed I&#8217;m having occasional issues with controllers resetting due to what appears to be a power problem) but for now things are working well enough.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>In looking to keep occupied with the current pandemic going on I&#8217;ve taken my Microelectronics projects to a new level and have over the past few weeks kicked out a series of soil moisture sensors which are powered by battery (18650) with a small solar panel keeping them topped up. As the battery charges\/discharges the voltage changes and moves outside&#8230; <a class=\"read-more\" href=\"https:\/\/myworldofit.net\/?p=11031\">Read more<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"ngg_post_thumbnail":0,"footnotes":""},"categories":[21,504],"tags":[508,507,505,506],"series":[],"class_list":["post-11031","post","type-post","status-publish","format-standard","hentry","category-hardware","category-microelectronics","tag-508","tag-esp32","tag-mcp1700","tag-mcp1700-3302e"],"_links":{"self":[{"href":"https:\/\/myworldofit.net\/index.php?rest_route=\/wp\/v2\/posts\/11031","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/myworldofit.net\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/myworldofit.net\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/myworldofit.net\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/myworldofit.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=11031"}],"version-history":[{"count":5,"href":"https:\/\/myworldofit.net\/index.php?rest_route=\/wp\/v2\/posts\/11031\/revisions"}],"predecessor-version":[{"id":11484,"href":"https:\/\/myworldofit.net\/index.php?rest_route=\/wp\/v2\/posts\/11031\/revisions\/11484"}],"wp:attachment":[{"href":"https:\/\/myworldofit.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=11031"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/myworldofit.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=11031"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/myworldofit.net\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=11031"},{"taxonomy":"series","embeddable":true,"href":"https:\/\/myworldofit.net\/index.php?rest_route=%2Fwp%2Fv2%2Fseries&post=11031"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}