I got this idea; instead of using a microphone and preamp at the end of a twisted pair, I would build a microphone, preamp and modulate a red laser with the audio and pick up the audio about ten yards away with a light detector.<\/p>\n
Notice that it runs on two 2V photovoltaic cells in series which charge up six .022 Farad supercaps in parallel to supply power if a cloud obscures the sunlight.<\/p>\n
I could use another solar cell to detect the laser beam. Or else a photodiode or phototransistor. I have also used a LED as a light sensing diode. I’ll then amplify the light beam to a usable signal.<\/p>\n
Update: I’m using a telephone earphone element and a 50mm square solar cell from an old garden light, and when the laser beam hits the solar cell, the audio is clear but actually a bit loud.<\/p>\n","protected":false},"excerpt":{"rendered":"
I got this idea; instead of using a microphone and preamp at the end of a twisted pair, I would build a microphone, preamp and modulate a red laser with the audio and pick up the audio about ten yards away with a light detector. Notice that it runs on two 2V photovoltaic cells in <\/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":[8,338,2032,77,143],"tags":[2169,2168],"class_list":["post-18202","post","type-post","status-publish","format-standard","hentry","category-audio","category-building-projects-and-kits","category-laser","category-leds","category-photovoltaic-and-solar-cells-or-panels","tag-laser-beam-communication","tag-microphone"],"_links":{"self":[{"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/18202","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=18202"}],"version-history":[{"count":3,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/18202\/revisions"}],"predecessor-version":[{"id":18209,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/18202\/revisions\/18209"}],"wp:attachment":[{"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=18202"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=18202"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=18202"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}