{"id":131,"date":"2011-10-19T20:56:39","date_gmt":"2011-10-20T03:56:39","guid":{"rendered":"http:\/\/usabledevices.com\/ud\/?p=131"},"modified":"2016-09-09T09:29:27","modified_gmt":"2016-09-09T09:29:27","slug":"safer-alarm-7400-competition-entry","status":"publish","type":"post","link":"http:\/\/usabledevices.com\/ud\/2011\/10\/safer-alarm-7400-competition-entry\/","title":{"rendered":"Safer Alarm &#8211; 7400 competition entry"},"content":{"rendered":"<p>There are several situations where common alarm systems fail to provide any indication that something bad has happened, such as the limited time sirens can sound. This\u00a0varies according to your local\/country regulations, and but when you return, the siren will most likely be off.<\/p>\n<p>Alarm strobes, if fitted are highly visible deterrents, but:<\/p>\n<ul>\n<li>generally provide no external fail safe indication<\/li>\n<li>no indication if power totally fails<\/li>\n<li>relatively heavy power use, so require a significant battery<\/li>\n<\/ul>\n<p>Alarm\u00a0strobe lights\u00a0can run from battery and be left on for long time, but if the the power has been cut off,\u00a0will your alarm survive without power during your annual holidays?<\/p>\n<p>This system provides a simple, effective and practical enhancement to existing alarm systems to tell you if your alarm has been triggered, tampered with, or lost power. It has been designed to minimise risks by:<\/p>\n<ul>\n<li>giving a safe to enter signal (Green led ONLY)<\/li>\n<li>has fail sale indication (NO indicator = issue)<\/li>\n<li>indicates if alarm system has been tripped (Red led)<\/li>\n<li>indicates if the alarm system has totally lost power (Yellow LED)<\/li>\n<li>can survive on it&#8217;s own power for 2+ months<\/li>\n<\/ul>\n<p>The schematic is shown below, and the Eagle version\u00a0is <a href=\"http:\/\/launchpad.net\/safer-alarm\" target=\"_blank\">here<\/a>.<\/p>\n<figure id=\"attachment_182\" aria-describedby=\"caption-attachment-182\" style=\"width: 695px\" class=\"wp-caption alignnone\"><a href=\"http:\/\/usabledevices.com\/udlocal1\/wp-content\/uploads\/2011\/10\/Safer-Alarm-schematic.png\"><img loading=\"lazy\" decoding=\"async\" class=\"size-large wp-image-182 \" title=\"Safer Alarm -  schematic\" src=\"http:\/\/usabledevices.com\/udlocal1\/wp-content\/uploads\/2011\/10\/Safer-Alarm-schematic-1024x508.png\" alt=\"Safer Alarm -  schematic\" width=\"695\" height=\"344\" \/><\/a><figcaption id=\"caption-attachment-182\" class=\"wp-caption-text\">Safer Alarm - schematic<\/figcaption><\/figure>\n<p>Informal testing has shown this circuit works well. It also survived 7+ weeks without power and around fifteen to twenty tests of the indicators.<\/p>\n<figure id=\"attachment_178\" aria-describedby=\"caption-attachment-178\" style=\"width: 300px\" class=\"wp-caption alignnone\"><a href=\"http:\/\/usabledevices.com\/udlocal1\/wp-content\/uploads\/2011\/10\/Safer-alarm-trimmed.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-178\" title=\"Safer alarm\" src=\"http:\/\/usabledevices.com\/udlocal1\/wp-content\/uploads\/2011\/10\/Safer-alarm-trimmed-300x96.jpg\" alt=\"Safer alarm\" width=\"300\" height=\"96\" \/><\/a><figcaption id=\"caption-attachment-178\" class=\"wp-caption-text\">Safer alarm<\/figcaption><\/figure>\n<p>Further testing using an Arduino and <a title=\"LiveGraph\" href=\"http:\/\/www.live-graph.org\/\" target=\"_blank\">LiveGraph<\/a> software shows a &#8216;pretty&#8217; graph of the charging of the super capacitor. I also wrote lots of test code to capture the discharge cycle and occasionally turn on the LEDs, but this went badly wrong as the Arduino test circuit injected power into the system via the flip flop inputs when it was logging, or drained power from the system when left connected, but switched off.<\/p>\n<p>&nbsp;<\/p>\n<figure id=\"attachment_177\" aria-describedby=\"caption-attachment-177\" style=\"width: 300px\" class=\"wp-caption alignnone\"><a href=\"http:\/\/usabledevices.com\/udlocal1\/wp-content\/uploads\/2011\/10\/safer-alarm-test-setup.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-177\" title=\"safer-alarm-test-setup\" src=\"http:\/\/usabledevices.com\/udlocal1\/wp-content\/uploads\/2011\/10\/safer-alarm-test-setup-300x250.jpg\" alt=\"safer alarm test setup\" width=\"300\" height=\"250\" \/><\/a><figcaption id=\"caption-attachment-177\" class=\"wp-caption-text\">safer alarm test setupCharging the supercap (LiveGraph)<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<figure id=\"attachment_173\" aria-describedby=\"caption-attachment-173\" style=\"width: 788px\" class=\"wp-caption alignnone\"><a href=\"http:\/\/usabledevices.com\/udlocal1\/wp-content\/uploads\/2011\/10\/Charging-the-supercap-LiveGraph.png\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-173\" title=\"Charging the supercap (LiveGraph)\" src=\"http:\/\/usabledevices.com\/udlocal1\/wp-content\/uploads\/2011\/10\/Charging-the-supercap-LiveGraph.png\" alt=\"Charging the supercap (LiveGraph)\" width=\"788\" height=\"575\" \/><\/a><figcaption id=\"caption-attachment-173\" class=\"wp-caption-text\">Charging the supercap (LiveGraph)<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p><a href=\"http:\/\/usabledevices.com\/udlocal1\/wp-content\/uploads\/2011\/10\/Safer-Alarm-all-indicators.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-174 alignnone\" title=\"Safer Alarm - all indicators\" src=\"http:\/\/usabledevices.com\/udlocal1\/wp-content\/uploads\/2011\/10\/Safer-Alarm-all-indicators-300x199.jpg\" alt=\"\" width=\"300\" height=\"199\" \/><\/a><\/p>\n<p>&nbsp;<\/p>\n<p>I have just <a title=\"safer alarm open source project\" href=\"http:\/\/launchpad.net\/safer-alarm\" target=\"_blank\">started an open source project <\/a>to get community help to take this project further. If this project was awarded any prizes,they would be used to encourage further community input to this project (and not given to me or my family, friends, relatives).<\/p>\n<p>Further enhancements could include the use of a pico power AtTiny PIC, this would also open opportunities for more enhancements, including more indicators or count of times alarm triggered, and remote indication, whilst keeping low price and matching input signals to typical alarm active collector active low outputs.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>There are several situations where common alarm systems fail to provide any indication that something bad has happened, such as the limited time sirens can sound. This\u00a0varies according to your local\/country regulations, and but when you return, the siren will most likely be off. Alarm strobes, if fitted are highly visible deterrents, but: generally provide &hellip; <a href=\"http:\/\/usabledevices.com\/ud\/2011\/10\/safer-alarm-7400-competition-entry\/\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> &#8220;Safer Alarm &#8211; 7400 competition entry&#8221;<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2,7,17],"tags":[26],"class_list":["post-131","post","type-post","status-publish","format-standard","hentry","category-devices","category-community","category-project-or-device","tag-alarm"],"_links":{"self":[{"href":"http:\/\/usabledevices.com\/ud\/wp-json\/wp\/v2\/posts\/131","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/usabledevices.com\/ud\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/usabledevices.com\/ud\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/usabledevices.com\/ud\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"http:\/\/usabledevices.com\/ud\/wp-json\/wp\/v2\/comments?post=131"}],"version-history":[{"count":1,"href":"http:\/\/usabledevices.com\/ud\/wp-json\/wp\/v2\/posts\/131\/revisions"}],"predecessor-version":[{"id":1391,"href":"http:\/\/usabledevices.com\/ud\/wp-json\/wp\/v2\/posts\/131\/revisions\/1391"}],"wp:attachment":[{"href":"http:\/\/usabledevices.com\/ud\/wp-json\/wp\/v2\/media?parent=131"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/usabledevices.com\/ud\/wp-json\/wp\/v2\/categories?post=131"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/usabledevices.com\/ud\/wp-json\/wp\/v2\/tags?post=131"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}