{"id":1120,"date":"2020-04-19T11:27:25","date_gmt":"2020-04-19T17:27:25","guid":{"rendered":"https:\/\/kjcrr.org\/?page_id=1120"},"modified":"2020-04-19T14:35:29","modified_gmt":"2020-04-19T20:35:29","slug":"optical-detector","status":"publish","type":"page","link":"https:\/\/kjcrr.org\/?page_id=1120","title":{"rendered":"Optical Detector"},"content":{"rendered":"<p>The design is very simple it is based on <a href=\"https:\/\/model-railroad-hobbyist.com\/node\/26133\" rel=\"noopener noreferrer\" target=\"_blank\">&#8220;A New DCC &#038; DC Car &#038; Loco Detector \u2013 Differential Absolute Position Detector (DAPD)&#8221;<\/a> by Geoff Bunza. I changed the IR detector to a PT334 and added an 18k resistor from the output to ground to  ensure the output is suitable for an ES32 or ESP82366 micro controller.<\/p>\n<p>The circuit has a few components:<\/p>\n<ul>\n<li>R1 &#8211; a 5.6K 1\/4 watt resistor<\/li>\n<li>R2 &#038; R3 &#8211; 10K 1\/4 watt resistors<\/li>\n<li>R4 &#8211; a 18K 1\/4 watt resistor<\/li>\n<li>Q1 &#038; Q2 &#8211; PT334 &#8211; 5mm phototransistors<\/li>\n<li>U1 &#8211; a Single Differential Comparator (SMD)<\/li>\n<\/ul>\n<p>The follow schematic shows the circuit<br \/>\n<img decoding=\"async\" src=\"https:\/\/kjcrr.org\/wp-content\/uploads\/2020\/04\/opdetector.png\" alt=\"opdetector circuit\" \/><br \/>\nThe PCB design can be found in <a href=\"https:\/\/github.com\/djbristow\/RAILS-HW\" target=\"_blank\" rel=\"noopener noreferrer\">my GitHub repository<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>The design is very simple it is based on &#8220;A New DCC &#038; DC Car &#038; Loco Detector \u2013 Differential Absolute Position Detector (DAPD)&#8221; by Geoff Bunza. I changed the IR detector to a PT334 and added an 18k resistor from the output to ground to ensure the output is suitable for an ES32 or\u2026 <span class=\"read-more\"><a href=\"https:\/\/kjcrr.org\/?page_id=1120\">Read More &raquo;<\/a><\/span><\/p>\n","protected":false},"author":1,"featured_media":0,"parent":768,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"page-templates\/full-width.php","meta":{"ngg_post_thumbnail":0,"footnotes":""},"class_list":["post-1120","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/kjcrr.org\/index.php?rest_route=\/wp\/v2\/pages\/1120","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/kjcrr.org\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/kjcrr.org\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/kjcrr.org\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/kjcrr.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1120"}],"version-history":[{"count":5,"href":"https:\/\/kjcrr.org\/index.php?rest_route=\/wp\/v2\/pages\/1120\/revisions"}],"predecessor-version":[{"id":1123,"href":"https:\/\/kjcrr.org\/index.php?rest_route=\/wp\/v2\/pages\/1120\/revisions\/1123"}],"up":[{"embeddable":true,"href":"https:\/\/kjcrr.org\/index.php?rest_route=\/wp\/v2\/pages\/768"}],"wp:attachment":[{"href":"https:\/\/kjcrr.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1120"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}