I made one of these back in 1970 or so. It was inside of a coffee can using the lid for the speaker.<\/p>\n
This class A power LED driver works good for making a speaker from an audio output transformer and any sheet of steel, even a coffee can with a steel cover.<\/p>\n
Strip the transformer and remove the ‘I’ laminations, leaving the ‘E’ laminations. Connect the speaker leads of the ‘E’ in place of the LED. Power up the class A power amp and connect it to a radio earphone output. Then hold the three ‘E’ lamination poles about 1\/8 inch or 3 mm away from the steel sheet, like the side of a washing machine. The steel sheet will transduce the audio.<\/p>\n","protected":false},"excerpt":{"rendered":"
I made one of these back in 1970 or so. It was inside of a coffee can using the lid for the speaker. This class A power LED driver works good for making a speaker from an audio output transformer and any sheet of steel, even a coffee can with a steel cover. Strip the <\/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":[347,8,338,293,346],"tags":[824],"class_list":["post-15205","post","type-post","status-publish","format-standard","hentry","category-amplifier","category-audio","category-building-projects-and-kits","category-do-it-yourself","category-speakers","tag-diy-speaker"],"_links":{"self":[{"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/15205","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=15205"}],"version-history":[{"count":1,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/15205\/revisions"}],"predecessor-version":[{"id":15206,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/15205\/revisions\/15206"}],"wp:attachment":[{"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=15205"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=15205"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=15205"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}