{"id":835,"date":"2011-03-22T17:07:56","date_gmt":"2011-03-22T17:07:56","guid":{"rendered":""},"modified":"2017-12-08T04:35:17","modified_gmt":"2017-12-08T04:35:17","slug":"designed-annunciator-light-con","status":"publish","type":"post","link":"http:\/\/jasonbeaver.com\/rv7\/2011\/03\/22\/designed-annunciator-light-con\/","title":{"rendered":"Designed Annunciator Light Controller Circuit"},"content":{"rendered":"<p>I&#8217;m planning on having 7 or 8 annunciator lights. \u00a0Some will be triggered when a signal is pulled to ground and others when a signal is pulled to 12V. \u00a0I also wanted a button to test all of the lights and a dimmer so I can reduce the brightness for night flight. \u00a0I couldn&#8217;t find an off the shelf controller that I liked, so I decided to dust off the old EE degree and design a simple circuit that did what I want. \u00a0I prototyped a two light version of the circuit below. \u00a0You can sort of see the two lights (red and yellow) near the top center of the picture. \u00a0The left switch at the bottom simulates the push-to-test button. \u00a0When thrown, both lights should light up. \u00a0The right switch simulates one of the circuits that should light an annunciator light when pulled to ground. \u00a0This circuit doesn&#8217;t handle signals pulled to high because I didn&#8217;t have any diodes on hand to do that portion of the circuit.<\/p>\n<p><center><a href=\"http:\/\/www.jasonbeaver.com\/rv7\/rv7pictures\/Originals\/20110322\/IMG_9187.jpg\"><img decoding=\"async\" src=\"http:\/\/jasonbeaver.com\/rv7\/wp-content\/uploads\/2017\/11\/IMG_9187.jpg\" \/><\/a><\/center><\/p>\n<p>Here&#8217;s the push-to-test switch thrown. \u00a0You can see both lights are on.<\/p>\n<p><center><a href=\"http:\/\/www.jasonbeaver.com\/rv7\/rv7pictures\/Originals\/20110322\/IMG_9188.jpg\"><img decoding=\"async\" src=\"http:\/\/jasonbeaver.com\/rv7\/wp-content\/uploads\/2017\/11\/IMG_9188.jpg\" \/><\/a><\/center><\/p>\n<p>Here&#8217;s the single signal light illuminated. \u00a0The lights only require 20mA at 12V, so a simple 2N2222A TO-92 NPN transistor can handle this without even warming up. \u00a0The end circuit only needs one diode, one resistor, and one transistor per light. \u00a0There&#8217;s one additional resistor in the circuit to handle one edge case that could blow a diode if one of the high signal pins were pulled to ground accidentally.<\/p>\n<p><center><a href=\"http:\/\/www.jasonbeaver.com\/rv7\/rv7pictures\/Originals\/20110322\/IMG_9189.jpg\"><img decoding=\"async\" src=\"http:\/\/jasonbeaver.com\/rv7\/wp-content\/uploads\/2017\/11\/IMG_9189.jpg\" \/><\/a><\/center><\/p>\n","protected":false},"excerpt":{"rendered":"<p>I&#8217;m planning on having 7 or 8 annunciator lights. \u00a0Some will be triggered when a signal is pulled to ground and others when a signal is pulled to 12V. \u00a0I also wanted a button to test all of the lights and a dimmer so I can reduce the brightness for night flight. \u00a0I couldn&#8217;t find &hellip; <a href=\"http:\/\/jasonbeaver.com\/rv7\/2011\/03\/22\/designed-annunciator-light-con\/\" class=\"excerpt-link\">Read More<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[8],"tags":[],"class_list":["post-835","post","type-post","status-publish","format-standard","hentry","category-avionics"],"_links":{"self":[{"href":"http:\/\/jasonbeaver.com\/rv7\/wp-json\/wp\/v2\/posts\/835","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/jasonbeaver.com\/rv7\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/jasonbeaver.com\/rv7\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/jasonbeaver.com\/rv7\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/jasonbeaver.com\/rv7\/wp-json\/wp\/v2\/comments?post=835"}],"version-history":[{"count":2,"href":"http:\/\/jasonbeaver.com\/rv7\/wp-json\/wp\/v2\/posts\/835\/revisions"}],"predecessor-version":[{"id":3092,"href":"http:\/\/jasonbeaver.com\/rv7\/wp-json\/wp\/v2\/posts\/835\/revisions\/3092"}],"wp:attachment":[{"href":"http:\/\/jasonbeaver.com\/rv7\/wp-json\/wp\/v2\/media?parent=835"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/jasonbeaver.com\/rv7\/wp-json\/wp\/v2\/categories?post=835"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/jasonbeaver.com\/rv7\/wp-json\/wp\/v2\/tags?post=835"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}