{"id":19826,"date":"2024-03-09T08:24:05","date_gmt":"2024-03-09T16:24:05","guid":{"rendered":"https:\/\/rustybolt.info\/wordpress\/?p=19826"},"modified":"2024-03-11T08:32:02","modified_gmt":"2024-03-11T15:32:02","slug":"2024-03-09-big-clives-old-tungsten-roadwork-beacon-barricade-flasher","status":"publish","type":"post","link":"https:\/\/rustybolt.info\/wordpress\/?p=19826","title":{"rendered":"2024-03-09 Big Clive’s Old Tungsten Roadwork Beacon – Barricade Flasher"},"content":{"rendered":"\n

I built this “tungsten roadwork beacon” as Clive calls it, using the parts given in my schematic (photo below).<\/p>\n\n\n\n

I didn’t have a 6V, 90 mA lamp, so I simulated it by using three 20 ohm, 1\/4 Watt resistors in series, which gives 60 ohms and 100 mA load with 6VDC.  For an indicator I put a blue LED with its 1k series current limiting resistor across the 60 ohm load.  <\/p>\n\n\n\n

The “tungsten” incandescent lamp has very low resistance, about 1\/10, when cold, so it draws ten times as much current when it is first turned on.  So this lamp can draw as much as 1 amp when first turned on.  The BC548 NPN transistor is a poor choice for the lamp driver because it can only handle 100 to 200 milliamps.   Anything more exceeds its maximum ratings.  So I used a PN2222A which can handle 800 mA.<\/p>\n\n\n\n

Link to Big Clive’s YouTube video, with schematic https:\/\/youtu.be\/tH2qW0tqhgo?si=QkHtGMSGMAhG5U27<\/p>\n\n\n\n

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\"\"<\/figure>\n","protected":false},"excerpt":{"rendered":"

I built this “tungsten roadwork beacon” as Clive calls it, using the parts given in my schematic (photo below). I didn’t have a 6V, 90 mA lamp, so I simulated it by using three 20 ohm, 1\/4 Watt resistors in series, which gives 60 ohms and 100 mA load with 6VDC.  For an indicator I <\/p>\n

(Read More…)<\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2881,144,338,293,142,12,77,357,330,79,296,129,1284,348],"tags":[3292,104,3291],"class_list":["post-19826","post","type-post","status-publish","format-standard","hentry","category-appliance","category-battery-or-cell","category-building-projects-and-kits","category-do-it-yourself","category-flashers-and-attention-getters","category-led","category-leds","category-modification","category-oscillators","category-resistors","category-schematics","category-security-and-safety","category-video-books-documents-literature","category-websites","tag-clive","tag-flasher","tag-roadwork-beacon"],"_links":{"self":[{"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/19826","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=19826"}],"version-history":[{"count":3,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/19826\/revisions"}],"predecessor-version":[{"id":19834,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/19826\/revisions\/19834"}],"wp:attachment":[{"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=19826"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=19826"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=19826"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}