{"id":1036,"date":"2017-02-14T11:24:17","date_gmt":"2017-02-14T10:24:17","guid":{"rendered":"https:\/\/pa3csg.nl\/?page_id=1036"},"modified":"2019-05-08T08:27:40","modified_gmt":"2019-05-08T06:27:40","slug":"fet-switch-with-ptt-and-alarm-inputs","status":"publish","type":"page","link":"https:\/\/pa3csg.nl\/?page_id=1036","title":{"rendered":"FET switch with PTT and alarm inputs"},"content":{"rendered":"<p>A FET switch to work together with the Arduino PWR \/ SWR meter and controllable by the PTT is published here.<\/p>\n<p>The FET is a IRF4905 and it works well up to 48V. For higher voltages you might want to use a different FET.<\/p>\n<p>It is very simple controlled by 2 cables connected to HEADER_2<\/p>\n<p><img loading=\"lazy\" class=\"wp-image-1052  aligncenter\" src=\"https:\/\/pa3csg.nl\/wp-content\/uploads\/2017\/02\/schema-psu-switch-300x214.jpg\" width=\"548\" height=\"391\" \/><\/p>\n<p>Pin 2 of the header will switch the 48V on the PA, just by simply grounding this pin.<\/p>\n<p>If pin 1 will go high, say +5V (in case of an alarm) the PA will switch off. This +5V comes from the Arduino PWR \/ SWR meter found on this website in case of a temperature alarm or a SWR alarm.<\/p>\n<p><img loading=\"lazy\" class=\" wp-image-1051 aligncenter\" src=\"https:\/\/pa3csg.nl\/wp-content\/uploads\/2017\/02\/DSC_5589-300x122.jpg\" alt=\"DSC_5589\" width=\"433\" height=\"176\" srcset=\"https:\/\/pa3csg.nl\/wp-content\/uploads\/2017\/02\/DSC_5589-300x122.jpg 300w, https:\/\/pa3csg.nl\/wp-content\/uploads\/2017\/02\/DSC_5589-600x244.jpg 600w, https:\/\/pa3csg.nl\/wp-content\/uploads\/2017\/02\/DSC_5589-1024x417.jpg 1024w\" sizes=\"(max-width: 433px) 100vw, 433px\" \/><\/p>\n<p>The FET requires some cooling but not much. The unit above is made for 48V.<\/p>\n<p>Below is a picture of a double unit build in my 700W 1296MHz PA. Slightly different resistor values are used. The 2 PTT&#8217;s are grounded via diodes.<\/p>\n<p><img loading=\"lazy\" class=\" wp-image-1049 aligncenter\" src=\"https:\/\/pa3csg.nl\/wp-content\/uploads\/2017\/02\/DSC_5585-300x244.jpg\" alt=\"DSC_5585\" width=\"586\" height=\"477\" srcset=\"https:\/\/pa3csg.nl\/wp-content\/uploads\/2017\/02\/DSC_5585-300x244.jpg 300w, https:\/\/pa3csg.nl\/wp-content\/uploads\/2017\/02\/DSC_5585-600x487.jpg 600w, https:\/\/pa3csg.nl\/wp-content\/uploads\/2017\/02\/DSC_5585-1024x832.jpg 1024w\" sizes=\"(max-width: 586px) 100vw, 586px\" \/><\/p>\n","protected":false},"excerpt":{"rendered":"<div class=\"mh-excerpt\"><p>A FET switch to work together with the Arduino PWR \/ SWR meter and controllable by the PTT is published here. The FET is a <a class=\"mh-excerpt-more\" href=\"https:\/\/pa3csg.nl\/?page_id=1036\" title=\"FET switch with PTT and alarm inputs\">[&#8230;]<\/a><\/p>\n<\/div>","protected":false},"author":1,"featured_media":1050,"parent":0,"menu_order":8,"comment_status":"closed","ping_status":"closed","template":"","meta":[],"categories":[29,20],"tags":[],"_links":{"self":[{"href":"https:\/\/pa3csg.nl\/index.php?rest_route=\/wp\/v2\/pages\/1036"}],"collection":[{"href":"https:\/\/pa3csg.nl\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/pa3csg.nl\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/pa3csg.nl\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/pa3csg.nl\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1036"}],"version-history":[{"count":10,"href":"https:\/\/pa3csg.nl\/index.php?rest_route=\/wp\/v2\/pages\/1036\/revisions"}],"predecessor-version":[{"id":1056,"href":"https:\/\/pa3csg.nl\/index.php?rest_route=\/wp\/v2\/pages\/1036\/revisions\/1056"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/pa3csg.nl\/index.php?rest_route=\/wp\/v2\/media\/1050"}],"wp:attachment":[{"href":"https:\/\/pa3csg.nl\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1036"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/pa3csg.nl\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1036"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/pa3csg.nl\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1036"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}