{"id":3335,"date":"2012-07-22T16:40:04","date_gmt":"2012-07-22T23:40:04","guid":{"rendered":"http:\/\/rustybolt.info\/wordpress\/?p=3335"},"modified":"2012-08-26T19:40:14","modified_gmt":"2012-08-27T02:40:14","slug":"2012-07-22","status":"publish","type":"post","link":"https:\/\/rustybolt.info\/wordpress\/?p=3335","title":{"rendered":"2012-07-22 MOSFET Phase Shift Oscillator"},"content":{"rendered":"<p><a href=\"http:\/\/rustybolt.info\/wordpress\/?attachment_id=3890\" rel=\"attachment wp-att-3890\"><img loading=\"lazy\" decoding=\"async\" class=\"alignright size-medium wp-image-3890\" title=\"DSCN1553S1\" src=\"http:\/\/rustybolt.info\/wordpress\/wp-content\/uploads\/2012\/07\/DSCN1553S1-300x251.jpg\" alt=\"\" width=\"300\" height=\"251\" srcset=\"https:\/\/rustybolt.info\/wordpress\/wp-content\/uploads\/2012\/07\/DSCN1553S1-300x251.jpg 300w, https:\/\/rustybolt.info\/wordpress\/wp-content\/uploads\/2012\/07\/DSCN1553S1.jpg 801w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a>I tack soldered this phase shift oscillator together and used a 2N7000 MOSFET for the PSO.\u00a0 The second transistor in the upper right is a 2N4401 being used as an emitter follower to drive the LED.\u00a0 The LED would draw too much current and load down the oscillator &#8211; the PSO has to have a voltage gain of at least 29 to oscillate.<\/p>\n<p>The three orange capacitors are 1 uF each.\u00a0 The 4.3 megohm resistors connect them to the drain and gate.\u00a0 The 4.7k resistor is the drain load resistor.\u00a0 The remaining 220 ohm resistor is to limit the current through the LED.\u00a0 The circuit oscillates subsonically, less than 1 Hz.\u00a0 This is dependent on the 4.3 meg resistors and 1 uF capacitors.\u00a0 The 2N7000 gate draws no current so the resistors can be very high without disturbing the bias.\u00a0 The supply voltage is about 5 volts.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>I tack soldered this phase shift oscillator together and used a 2N7000 MOSFET for the PSO.\u00a0 The second transistor in the upper right is a 2N4401 being used as an emitter follower to drive the LED.\u00a0 The LED would draw too much current and load down the oscillator &#8211; the PSO has to have a<a href=\"https:\/\/rustybolt.info\/wordpress\/?p=3335\"> <\/p>\n<p> (Read More&#8230;)<\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[8,12,13],"tags":[],"class_list":["post-3335","post","type-post","status-publish","format-standard","hentry","category-audio","category-led","category-lighting"],"_links":{"self":[{"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/3335","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=3335"}],"version-history":[{"count":9,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/3335\/revisions"}],"predecessor-version":[{"id":3888,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/3335\/revisions\/3888"}],"wp:attachment":[{"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3335"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3335"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3335"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}