{"id":226,"date":"2018-08-13T20:14:53","date_gmt":"2018-08-13T20:14:53","guid":{"rendered":"http:\/\/commons.princeton.edu\/63-tiger-cub\/?page_id=226"},"modified":"2018-08-13T20:14:53","modified_gmt":"2018-08-13T20:14:53","slug":"testing","status":"publish","type":"page","link":"https:\/\/commons.princeton.edu\/63-tiger-cub\/testing\/","title":{"rendered":"Testing"},"content":{"rendered":"<figure id=\"attachment_228\" aria-describedby=\"caption-attachment-228\" style=\"width: 977px\" class=\"wp-caption alignnone\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-228 \" src=\"http:\/\/commons.princeton.edu\/63-tiger-cub\/wp-content\/uploads\/sites\/74\/2018\/08\/oscope.jpg\" alt=\"\" width=\"977\" height=\"651\" srcset=\"https:\/\/commons.princeton.edu\/63-tiger-cub\/wp-content\/uploads\/sites\/74\/2018\/08\/oscope.jpg 648w, https:\/\/commons.princeton.edu\/63-tiger-cub\/wp-content\/uploads\/sites\/74\/2018\/08\/oscope-300x200.jpg 300w\" sizes=\"auto, (max-width: 709px) 85vw, (max-width: 909px) 67vw, (max-width: 1362px) 62vw, 840px\" \/><figcaption id=\"caption-attachment-228\" class=\"wp-caption-text\">O-Scope Trace<\/figcaption><\/figure>\n<p>This waveform was obtained when the points opened.\u00a0 The probe was on the low voltage side &#8212; that is across the primary.\u00a0 Measurements were made with C of .1uf, and L (primary of the ignition coil) which is about 5 mH.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone  wp-image-227\" src=\"http:\/\/commons.princeton.edu\/63-tiger-cub\/wp-content\/uploads\/sites\/74\/2018\/08\/oscope2.jpg\" alt=\"\" width=\"973\" height=\"784\" srcset=\"https:\/\/commons.princeton.edu\/63-tiger-cub\/wp-content\/uploads\/sites\/74\/2018\/08\/oscope2.jpg 514w, https:\/\/commons.princeton.edu\/63-tiger-cub\/wp-content\/uploads\/sites\/74\/2018\/08\/oscope2-300x242.jpg 300w\" sizes=\"auto, (max-width: 709px) 85vw, (max-width: 909px) 67vw, (max-width: 1362px) 62vw, 840px\" \/><\/p>\n<p>waveform was obtained with the tester shown on the main page.\u00a0 Stator voltage is trace 2.\u00a0 Stator current is trace 3. Points opening is trace 1.\u00a0 Points only open once per revolution of the rotor.\u00a0 Trigger condition is the firing of the spark plug.\u00a0 Note that the current peaks after the voltage peaks.\u00a0 The strongest spark is obtained when the points are timed to open when the current is a maximum.\u00a0 This makes sense because the energy stored in the stator is 0.5*L*I^2, where L is the stator inductance and I is the current.<\/p>\n<p>As the magnetic field collapses with peak energy stored in the inductor, this large change in flux leads to a large back voltage. As this large potential goes across the transformer, it&#8217;s &#8216;stepped-up&#8217; to several thousand volts.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>This waveform was obtained when the points opened.\u00a0 The probe was on the low voltage side &#8212; that is across the primary.\u00a0 Measurements were made with C of .1uf, and L (primary of the ignition coil) which is about 5 mH. waveform was obtained with the tester shown on the main page.\u00a0 Stator voltage is &hellip; <a href=\"https:\/\/commons.princeton.edu\/63-tiger-cub\/testing\/\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> &#8220;Testing&#8221;<\/span><\/a><\/p>\n","protected":false},"author":6,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-226","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/commons.princeton.edu\/63-tiger-cub\/wp-json\/wp\/v2\/pages\/226","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/commons.princeton.edu\/63-tiger-cub\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/commons.princeton.edu\/63-tiger-cub\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/commons.princeton.edu\/63-tiger-cub\/wp-json\/wp\/v2\/users\/6"}],"replies":[{"embeddable":true,"href":"https:\/\/commons.princeton.edu\/63-tiger-cub\/wp-json\/wp\/v2\/comments?post=226"}],"version-history":[{"count":1,"href":"https:\/\/commons.princeton.edu\/63-tiger-cub\/wp-json\/wp\/v2\/pages\/226\/revisions"}],"predecessor-version":[{"id":229,"href":"https:\/\/commons.princeton.edu\/63-tiger-cub\/wp-json\/wp\/v2\/pages\/226\/revisions\/229"}],"wp:attachment":[{"href":"https:\/\/commons.princeton.edu\/63-tiger-cub\/wp-json\/wp\/v2\/media?parent=226"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}