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CircuitsTune"},"subtitle":{"type":"html","$t":"A birth place of electronic schematic circuit diagram"},"link":[{"rel":"http://schemas.google.com/g/2005#feed","type":"application/atom+xml","href":"https:\/\/www.circuitstune.com\/feeds\/posts\/default"},{"rel":"self","type":"application/atom+xml","href":"https:\/\/www.blogger.com\/feeds\/4092621447904023766\/posts\/default\/-\/Astable+Multivibrator?alt=json-in-script\u0026max-results=6"},{"rel":"alternate","type":"text/html","href":"https:\/\/www.circuitstune.com\/search\/label\/Astable%20Multivibrator"},{"rel":"hub","href":"http://pubsubhubbub.appspot.com/"}],"author":[{"name":{"$t":"Unknown"},"email":{"$t":"noreply@blogger.com"},"gd$image":{"rel":"http://schemas.google.com/g/2005#thumbnail","width":"16","height":"16","src":"https:\/\/img1.blogblog.com\/img\/b16-rounded.gif"}}],"generator":{"version":"7.00","uri":"http://www.blogger.com","$t":"Blogger"},"openSearch$totalResults":{"$t":"1"},"openSearch$startIndex":{"$t":"1"},"openSearch$itemsPerPage":{"$t":"6"},"entry":[{"id":{"$t":"tag:blogger.com,1999:blog-4092621447904023766.post-8077951274467573594"},"published":{"$t":"2012-01-21T20:57:00.002+06:00"},"updated":{"$t":"2012-12-25T11:14:36.872+06:00"},"category":[{"scheme":"http://www.blogger.com/atom/ns#","term":"2N3904"},{"scheme":"http://www.blogger.com/atom/ns#","term":"Astable Multivibrator"},{"scheme":"http://www.blogger.com/atom/ns#","term":"Fun Circuit"},{"scheme":"http://www.blogger.com/atom/ns#","term":"LED and Light"},{"scheme":"http://www.blogger.com/atom/ns#","term":"Led Flashing"},{"scheme":"http://www.blogger.com/atom/ns#","term":"Transistor Circuit"}],"title":{"type":"text","$t":"Astable multivibrator-2 LED flashing circuit,2N3904,3.7V"},"content":{"type":"html","$t":"\u003Cdiv dir=\"ltr\" style=\"text-align: left;\" trbidi=\"on\"\u003E\nMany of my friends asked me for automatic on off led circuit or\u0026nbsp; led flashing circuit so here I’m going to post a Astable multivibrator-2 LED flashing circuit.\u003Cbr \/\u003E\n\u003Cbr \/\u003E\n\u003Ch3 style=\"text-align: left;\"\u003E\n\u003Cb\u003ECircuit diagram of Astable multivibrator with 2 LED:\u003C\/b\u003E\u003C\/h3\u003E\n\u003Cbr \/\u003E\n\u003Ctable align=\"center\" cellpadding=\"0\" cellspacing=\"0\" class=\"tr-caption-container\" style=\"margin-left: auto; margin-right: auto; text-align: center;\"\u003E\u003Ctbody\u003E\n\u003Ctr\u003E\u003Ctd style=\"text-align: center;\"\u003E\u003Ca href=\"https:\/\/blogger.googleusercontent.com\/img\/b\/R29vZ2xl\/AVvXsEgH8q_ZGdBCmGGaRTc-V82_YQLg0TAEtnW-NM_I9rNEP-JVzY-9sAN8bdQpRpkbXle4D8IeOUQY-9BUjraXvRLtzF10EDSB4CT5b-YSjAak9Oxn7Br4GpiQ3L2PVFiQ_xrkU2VV1Y6Z-XI\/s1600\/Astable+multivibrator-2+LED+flashing+circuit-2N3904.gif\" imageanchor=\"1\" style=\"margin-left: auto; margin-right: auto;\"\u003E\u003Cimg alt=\"Astable multivibrator circuit\" border=\"0\" src=\"https:\/\/blogger.googleusercontent.com\/img\/b\/R29vZ2xl\/AVvXsEgH8q_ZGdBCmGGaRTc-V82_YQLg0TAEtnW-NM_I9rNEP-JVzY-9sAN8bdQpRpkbXle4D8IeOUQY-9BUjraXvRLtzF10EDSB4CT5b-YSjAak9Oxn7Br4GpiQ3L2PVFiQ_xrkU2VV1Y6Z-XI\/s1600\/Astable+multivibrator-2+LED+flashing+circuit-2N3904.gif\" title=\"\" \/\u003E\u003C\/a\u003E\u003C\/td\u003E\u003C\/tr\u003E\n\u003Ctr\u003E\u003Ctd class=\"tr-caption\" style=\"text-align: center;\"\u003E\u003Ci\u003EFig:\u0026nbsp; Astable multivibrator-2 LED flashing circuit Circuit diagram\u003C\/i\u003E\u003C\/td\u003E\u003C\/tr\u003E\n\u003C\/tbody\u003E\u003C\/table\u003E\nIt is a simple astable multivibrator circuit using 2LED (here i used red LED), two NPN small transistor 2N3904 for switching. Here other small NPN transistor can be used, including\u0026nbsp; 2N4401, 2N2222 or PN2222. Supply voltage is +3.7V to +5V or if you want to supply a larger volt then add a required resistor series connected with\u0026nbsp; 2 LED’s. I recommend to use +3.7V for best result . for +3.7V you can use a battery of\u0026nbsp; mobile phone.\u003Cbr \/\u003E\n\u003Cdiv style=\"text-align: justify;\"\u003E\n\u003Ca name='more'\u003E\u003C\/a\u003E\u003Cbr \/\u003E\nThe 5K ohms resistor and the 220uF capacitor determines the LED on time(flashing) for each side. You can experiment by changing the 5K \u0026amp; 220uF value.\u003C\/div\u003E\n\u003Cbr \/\u003E\n\u003Cb\u003E\u003Cbr \/\u003E\u003C\/b\u003E\n\u003Cb\u003EPin diagram of transistor 2N3904\u003C\/b\u003E:\u003Cbr \/\u003E\n\u003Cbr \/\u003E\n\u003Ctable align=\"center\" cellpadding=\"0\" cellspacing=\"0\" class=\"tr-caption-container\" style=\"margin-left: auto; margin-right: auto; text-align: center;\"\u003E\u003Ctbody\u003E\n\u003Ctr\u003E\u003Ctd style=\"text-align: center;\"\u003E\u003Ca href=\"https:\/\/blogger.googleusercontent.com\/img\/b\/R29vZ2xl\/AVvXsEjtte_8fHEAi-LV8CqDIpO9BhlnKeC_HgM6j-Os_CimJY49fMXj3EquVDiyGRqji0Tj1E6A553WPfaSIaERtBv0_MGBPhSI05hBV3Trl4gp1KCNB5qdSyojjVPIyzhRkuCJdCcd0_B5xEU\/s1600\/Transistor-2N3904-Pin-diagram.png\" imageanchor=\"1\" style=\"margin-left: auto; margin-right: auto;\"\u003E\u003Cimg alt=\"2N3904 pinout\" border=\"0\" height=\"240\" src=\"https:\/\/blogger.googleusercontent.com\/img\/b\/R29vZ2xl\/AVvXsEjtte_8fHEAi-LV8CqDIpO9BhlnKeC_HgM6j-Os_CimJY49fMXj3EquVDiyGRqji0Tj1E6A553WPfaSIaERtBv0_MGBPhSI05hBV3Trl4gp1KCNB5qdSyojjVPIyzhRkuCJdCcd0_B5xEU\/s320\/Transistor-2N3904-Pin-diagram.png\" title=\"\" width=\"320\" \/\u003E\u003C\/a\u003E\u003C\/td\u003E\u003C\/tr\u003E\n\u003Ctr\u003E\u003Ctd class=\"tr-caption\" style=\"text-align: center;\"\u003E\u003Ci\u003EFig: 2N3904 Pin Diagram\u003C\/i\u003E\u003Cb\u003E\u003Cbr \/\u003E\u003C\/b\u003E\u003C\/td\u003E\u003C\/tr\u003E\n\u003C\/tbody\u003E\u003C\/table\u003E\n\u003C\/div\u003E\n"},"link":[{"rel":"replies","type":"application/atom+xml","href":"https:\/\/www.circuitstune.com\/feeds\/8077951274467573594\/comments\/default","title":"Post Comments"},{"rel":"replies","type":"text/html","href":"https:\/\/www.circuitstune.com\/2012\/01\/astable-multivibrator-2-led-flashing.html#comment-form","title":"6 Comments"},{"rel":"edit","type":"application/atom+xml","href":"https:\/\/www.blogger.com\/feeds\/4092621447904023766\/posts\/default\/8077951274467573594"},{"rel":"self","type":"application/atom+xml","href":"https:\/\/www.blogger.com\/feeds\/4092621447904023766\/posts\/default\/8077951274467573594"},{"rel":"alternate","type":"text/html","href":"https:\/\/www.circuitstune.com\/2012\/01\/astable-multivibrator-2-led-flashing.html","title":"Astable multivibrator-2 LED flashing circuit,2N3904,3.7V"}],"author":[{"name":{"$t":"Unknown"},"email":{"$t":"noreply@blogger.com"},"gd$image":{"rel":"http://schemas.google.com/g/2005#thumbnail","width":"16","height":"16","src":"https:\/\/img1.blogblog.com\/img\/b16-rounded.gif"}}],"media$thumbnail":{"xmlns$media":"http://search.yahoo.com/mrss/","url":"https:\/\/blogger.googleusercontent.com\/img\/b\/R29vZ2xl\/AVvXsEgH8q_ZGdBCmGGaRTc-V82_YQLg0TAEtnW-NM_I9rNEP-JVzY-9sAN8bdQpRpkbXle4D8IeOUQY-9BUjraXvRLtzF10EDSB4CT5b-YSjAak9Oxn7Br4GpiQ3L2PVFiQ_xrkU2VV1Y6Z-XI\/s72-c\/Astable+multivibrator-2+LED+flashing+circuit-2N3904.gif","height":"72","width":"72"},"thr$total":{"$t":"6"},"georss$featurename":{"$t":"Dhaka, Bangladesh"},"georss$point":{"$t":"23.709921 90.407143000000019"},"georss$box":{"$t":"23.596680000000003 90.312930500000022 23.823162 90.501355500000017"}}]}});