{"id":2058,"date":"2014-08-20T22:56:19","date_gmt":"2014-08-21T01:56:19","guid":{"rendered":"http:\/\/tangopardo.com.ar\/2cf7\/?p=2058"},"modified":"2014-08-20T22:56:19","modified_gmt":"2014-08-21T01:56:19","slug":"bypassing","status":"publish","type":"post","link":"https:\/\/tangopardo.com.ar\/2cf7\/2014\/08\/20\/bypassing","title":{"rendered":"Bypassing."},"content":{"rendered":"<p>This happens when you forget to add a &#8216;lytic after the regulator, although the datasheet only shows a 100nF on the output. Not that it really matters on this case. On the <a title=\"Inductor saturation tester\" href=\"http:\/\/tangopardo.com.ar\/2cf7\/2014\/08\/11\/inductor-saturation-tester\">pulse generator<\/a> the logic gates are fed from a regulated supply, mostly so I can forget and use the same as the output stage. Without load and having only a 100nF ceramic halfway between the 7805 and the 4093 (less than a cm&#8230;) the rail bounces about 300mVp-p, but it becomes negligible when using a small 10uF in parallel.<\/p>\n\n\t\t<style type=\"text\/css\">\n\t\t\t#gallery-1 {\n\t\t\t\tmargin: auto;\n\t\t\t}\n\t\t\t#gallery-1 .gallery-item {\n\t\t\t\tfloat: left;\n\t\t\t\tmargin-top: 10px;\n\t\t\t\ttext-align: center;\n\t\t\t\twidth: 50%;\n\t\t\t}\n\t\t\t#gallery-1 img {\n\t\t\t\tborder: 2px solid #cfcfcf;\n\t\t\t}\n\t\t\t#gallery-1 .gallery-caption {\n\t\t\t\tmargin-left: 0;\n\t\t\t}\n\t\t\t\/* see gallery_shortcode() in wp-includes\/media.php *\/\n\t\t<\/style>\n\t\t<div data-carousel-extra='{\"blog_id\":1,\"permalink\":\"https:\\\/\\\/tangopardo.com.ar\\\/2cf7\\\/2014\\\/08\\\/20\\\/bypassing\"}' id='gallery-1' class='gallery galleryid-2058 gallery-columns-2 gallery-size-thumbnail'><dl class='gallery-item'>\n\t\t\t<dt class='gallery-icon landscape'>\n\t\t\t\t<a href='https:\/\/tangopardo.com.ar\/2cf7\/wp-content\/uploads\/2014\/08\/regulator_without_cfilter.png'><img loading=\"lazy\" decoding=\"async\" width=\"150\" height=\"150\" src=\"https:\/\/tangopardo.com.ar\/2cf7\/wp-content\/uploads\/2014\/08\/regulator_without_cfilter-150x150.png\" class=\"attachment-thumbnail size-thumbnail\" alt=\"\" aria-describedby=\"gallery-1-2066\" data-attachment-id=\"2066\" data-permalink=\"https:\/\/tangopardo.com.ar\/2cf7\/2014\/08\/20\/bypassing\/regulator_without_cfilter\" data-orig-file=\"https:\/\/tangopardo.com.ar\/2cf7\/wp-content\/uploads\/2014\/08\/regulator_without_cfilter.png\" data-orig-size=\"800,480\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;}\" data-image-title=\"regulator_without_cfilter\" data-image-description=\"\" data-image-caption=\"&lt;p&gt;Yellow: pulse output. Blue: ac component of vcc without bypass.&lt;\/p&gt;\n\" data-medium-file=\"https:\/\/tangopardo.com.ar\/2cf7\/wp-content\/uploads\/2014\/08\/regulator_without_cfilter-300x180.png\" data-large-file=\"https:\/\/tangopardo.com.ar\/2cf7\/wp-content\/uploads\/2014\/08\/regulator_without_cfilter.png\" \/><\/a>\n\t\t\t<\/dt>\n\t\t\t\t<dd class='wp-caption-text gallery-caption' id='gallery-1-2066'>\n\t\t\t\tYellow: pulse output. Blue: ac component of vcc without bypass.\n\t\t\t\t<\/dd><\/dl><dl class='gallery-item'>\n\t\t\t<dt class='gallery-icon landscape'>\n\t\t\t\t<a href='https:\/\/tangopardo.com.ar\/2cf7\/wp-content\/uploads\/2014\/08\/regulator_with_cfilter.png'><img loading=\"lazy\" decoding=\"async\" width=\"150\" height=\"150\" src=\"https:\/\/tangopardo.com.ar\/2cf7\/wp-content\/uploads\/2014\/08\/regulator_with_cfilter-150x150.png\" class=\"attachment-thumbnail size-thumbnail\" alt=\"\" aria-describedby=\"gallery-1-2065\" data-attachment-id=\"2065\" data-permalink=\"https:\/\/tangopardo.com.ar\/2cf7\/2014\/08\/20\/bypassing\/regulator_with_cfilter\" data-orig-file=\"https:\/\/tangopardo.com.ar\/2cf7\/wp-content\/uploads\/2014\/08\/regulator_with_cfilter.png\" data-orig-size=\"800,480\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;}\" data-image-title=\"regulator_with_cfilter\" data-image-description=\"\" data-image-caption=\"&lt;p&gt;Yellow: pulse output. Blue: ac component of vcc with bypass.&lt;\/p&gt;\n\" data-medium-file=\"https:\/\/tangopardo.com.ar\/2cf7\/wp-content\/uploads\/2014\/08\/regulator_with_cfilter-300x180.png\" data-large-file=\"https:\/\/tangopardo.com.ar\/2cf7\/wp-content\/uploads\/2014\/08\/regulator_with_cfilter.png\" \/><\/a>\n\t\t\t<\/dt>\n\t\t\t\t<dd class='wp-caption-text gallery-caption' id='gallery-1-2065'>\n\t\t\t\tYellow: pulse output. Blue: ac component of vcc with bypass.\n\t\t\t\t<\/dd><\/dl><br style=\"clear: both\" \/>\n\t\t<\/div>\n\n<p>Just for kicks I removed the ceramic cap, leaving the output without bypassing at all. The result was a set of narrower 800mVp-p spikes that settled quite fast.<\/p>\n\n\t\t<style type=\"text\/css\">\n\t\t\t#gallery-2 {\n\t\t\t\tmargin: auto;\n\t\t\t}\n\t\t\t#gallery-2 .gallery-item {\n\t\t\t\tfloat: left;\n\t\t\t\tmargin-top: 10px;\n\t\t\t\ttext-align: center;\n\t\t\t\twidth: 100%;\n\t\t\t}\n\t\t\t#gallery-2 img {\n\t\t\t\tborder: 2px solid #cfcfcf;\n\t\t\t}\n\t\t\t#gallery-2 .gallery-caption {\n\t\t\t\tmargin-left: 0;\n\t\t\t}\n\t\t\t\/* see gallery_shortcode() in wp-includes\/media.php *\/\n\t\t<\/style>\n\t\t<div data-carousel-extra='{\"blog_id\":1,\"permalink\":\"https:\\\/\\\/tangopardo.com.ar\\\/2cf7\\\/2014\\\/08\\\/20\\\/bypassing\"}' id='gallery-2' class='gallery galleryid-2058 gallery-columns-1 gallery-size-thumbnail'><dl class='gallery-item'>\n\t\t\t<dt class='gallery-icon landscape'>\n\t\t\t\t<a href='https:\/\/tangopardo.com.ar\/2cf7\/wp-content\/uploads\/2014\/08\/regulator_without_cfilter2.png'><img loading=\"lazy\" decoding=\"async\" width=\"150\" height=\"150\" src=\"https:\/\/tangopardo.com.ar\/2cf7\/wp-content\/uploads\/2014\/08\/regulator_without_cfilter2-150x150.png\" class=\"attachment-thumbnail size-thumbnail\" alt=\"\" data-attachment-id=\"2067\" data-permalink=\"https:\/\/tangopardo.com.ar\/2cf7\/2014\/08\/20\/bypassing\/regulator_without_cfilter2\" data-orig-file=\"https:\/\/tangopardo.com.ar\/2cf7\/wp-content\/uploads\/2014\/08\/regulator_without_cfilter2.png\" data-orig-size=\"800,480\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;}\" data-image-title=\"regulator_without_cfilter2\" data-image-description=\"\" data-image-caption=\"\" data-medium-file=\"https:\/\/tangopardo.com.ar\/2cf7\/wp-content\/uploads\/2014\/08\/regulator_without_cfilter2-300x180.png\" data-large-file=\"https:\/\/tangopardo.com.ar\/2cf7\/wp-content\/uploads\/2014\/08\/regulator_without_cfilter2.png\" \/><\/a>\n\t\t\t<\/dt><\/dl><br style=\"clear: both\" \/>\n\t\t<\/div>\n\n","protected":false},"excerpt":{"rendered":"<p>This happens when you forget to add a &#8216;lytic after the regulator, although the datasheet only shows a 100nF on the output. Not that it really matters on this case. On the pulse generator the logic gates are fed from a regulated supply, mostly so I can forget and use the same as the output [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[13,24],"tags":[],"class_list":["post-2058","post","type-post","status-publish","format-standard","hentry","category-electronica","category-hacks"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/pmnbC-xc","_links":{"self":[{"href":"https:\/\/tangopardo.com.ar\/2cf7\/wp-json\/wp\/v2\/posts\/2058","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/tangopardo.com.ar\/2cf7\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/tangopardo.com.ar\/2cf7\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/tangopardo.com.ar\/2cf7\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/tangopardo.com.ar\/2cf7\/wp-json\/wp\/v2\/comments?post=2058"}],"version-history":[{"count":2,"href":"https:\/\/tangopardo.com.ar\/2cf7\/wp-json\/wp\/v2\/posts\/2058\/revisions"}],"predecessor-version":[{"id":2069,"href":"https:\/\/tangopardo.com.ar\/2cf7\/wp-json\/wp\/v2\/posts\/2058\/revisions\/2069"}],"wp:attachment":[{"href":"https:\/\/tangopardo.com.ar\/2cf7\/wp-json\/wp\/v2\/media?parent=2058"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/tangopardo.com.ar\/2cf7\/wp-json\/wp\/v2\/categories?post=2058"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/tangopardo.com.ar\/2cf7\/wp-json\/wp\/v2\/tags?post=2058"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}