{"id":8950,"date":"2019-09-07T19:15:41","date_gmt":"2019-09-07T19:15:41","guid":{"rendered":"https:\/\/stevepedwards.today\/stevepedwards.com\/ElectronicsStuff\/?p=8621"},"modified":"2019-09-07T19:15:41","modified_gmt":"2019-09-07T19:15:41","slug":"astable-multivibrators-from-transistors-and-555-timer","status":"publish","type":"post","link":"https:\/\/stevepedwards.today\/ElectronicsStuff\/astable-multivibrators-from-transistors-and-555-timer\/","title":{"rendered":"Astable Multivibrators from Transistors and 555 Timer"},"content":{"rendered":"<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-large wp-image-8631\" src=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2019\/09\/Xtal-1024x576.png\" alt=\"\" width=\"840\" height=\"473\" srcset=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2019\/09\/Xtal-1024x576.png 1024w, https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2019\/09\/Xtal-300x169.png 300w, https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2019\/09\/Xtal-768x432.png 768w, https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2019\/09\/Xtal-1200x675.png 1200w, https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2019\/09\/Xtal.png 1920w\" sizes=\"auto, (max-width: 840px) 100vw, 840px\" \/>Above is Scott's Crystal Oscillator circuit I failed with due to not having correct value parts (and it seems crystals are a pig to get oscillating on a breadboard anyway!), so moved on to his astable multivibrator circuit instead. I had some hassle getting this thing going too due to bad bread board connections (used 2N2222 transistors), as with no caps, the LEDs light anyway but stay on!<br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-8703\" src=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2019\/09\/astable.png\" alt=\"\" width=\"399\" height=\"431\" \/><br \/>\nI changed Scott's 10uF to 100uF caps to slow it down,-\u00a0 to be sure I could see change. Later, when working, the 10uF caps gave-\u00a0 a 16.8Hz ramp --\u00a0 an annoying flicker rate! 100uFs gave a 1.39Hz ramp.<br \/>\n<iframe loading=\"lazy\" title=\"Astable multivibrator\" width=\"1333\" height=\"1000\" src=\"https:\/\/www.youtube.com\/embed\/wYaaHFZqwN0?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe><br \/>\nMove your probe to different places to see the various ramp waveforms possible.<br \/>\n<iframe loading=\"lazy\" title=\"Electronic Basics #17: Oscillators || RC, LC, Crystal\" width=\"1778\" height=\"1000\" src=\"https:\/\/www.youtube.com\/embed\/eYVOdlK15Og?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe><br \/>\n555 Timer Circuit using 100uF Caps<br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-large wp-image-8873\" src=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2019\/09\/555-Astable-Circuit-Diagram-1024x739.gif\" alt=\"\" width=\"840\" height=\"606\" srcset=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2019\/09\/555-Astable-Circuit-Diagram-1024x739.gif 1024w, https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2019\/09\/555-Astable-Circuit-Diagram-300x216.gif 300w, https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2019\/09\/555-Astable-Circuit-Diagram-768x554.gif 768w, https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2019\/09\/555-Astable-Circuit-Diagram-1200x866.gif 1200w\" sizes=\"auto, (max-width: 840px) 100vw, 840px\" \/><br \/>\nGives about 2\/3 sec flash with 10uF caps:<br \/>\n<iframe loading=\"lazy\" title=\"555 astable multivibrator\" width=\"1778\" height=\"1000\" src=\"https:\/\/www.youtube.com\/embed\/-YQcdVlD8n4?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe><br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-large wp-image-8875\" src=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2019\/09\/555int-1024x491.png\" alt=\"\" width=\"840\" height=\"403\" srcset=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2019\/09\/555int-1024x491.png 1024w, https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2019\/09\/555int-300x144.png 300w, https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2019\/09\/555int-768x369.png 768w, https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2019\/09\/555int.png 1119w\" sizes=\"auto, (max-width: 840px) 100vw, 840px\" \/><br \/>\n5V timing circuit from datasheet - I used 1uF caps and 3k3 resistors so 10 times slower than pdf circuit, but same results:<br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-8877\" src=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2019\/09\/astablepdf.png\" alt=\"\" width=\"529\" height=\"737\" srcset=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2019\/09\/astablepdf.png 529w, https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2019\/09\/astablepdf-215x300.png 215w\" sizes=\"auto, (max-width: 529px) 100vw, 529px\" \/><br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-8878\" src=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2019\/09\/astab5vtimer.png\" alt=\"\" width=\"821\" height=\"403\" srcset=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2019\/09\/astab5vtimer.png 821w, https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2019\/09\/astab5vtimer-300x147.png 300w, https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2019\/09\/astab5vtimer-768x377.png 768w\" sizes=\"auto, (max-width: 821px) 100vw, 821px\" \/><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Above is Scott's Crystal Oscillator circuit I failed with due to not having correct value parts (and it seems crystals are a pig to get oscillating on a breadboard anyway!), so moved on to his astable multivibrator circuit instead. I had some hassle getting this thing going too due to bad bread board connections (used <a href=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/astable-multivibrators-from-transistors-and-555-timer\/\" class=\"more-link\">...<span class=\"screen-reader-text\">  Astable Multivibrators from Transistors and 555 Timer<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5,2],"tags":[],"class_list":["post-8950","post","type-post","status-publish","format-standard","hentry","category-tech-studies","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-json\/wp\/v2\/posts\/8950","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-json\/wp\/v2\/comments?post=8950"}],"version-history":[{"count":0,"href":"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-json\/wp\/v2\/posts\/8950\/revisions"}],"wp:attachment":[{"href":"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-json\/wp\/v2\/media?parent=8950"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-json\/wp\/v2\/categories?post=8950"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-json\/wp\/v2\/tags?post=8950"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}