{"id":11679,"date":"2016-11-23T08:02:36","date_gmt":"2016-11-23T16:02:36","guid":{"rendered":"http:\/\/rustybolt.info\/wordpress\/?p=11679"},"modified":"2016-11-23T08:22:04","modified_gmt":"2016-11-23T16:22:04","slug":"2016-11-22-coil-of-wire-is-air-core-inductor","status":"publish","type":"post","link":"https:\/\/rustybolt.info\/wordpress\/?p=11679","title":{"rendered":"2016-11-22 Coil of Wire Is Air Core Inductor"},"content":{"rendered":"<p>I bought two of these <a href=\"http:\/\/www.goldmine-elec-products.com\/prodinfo.asp?number=G21759\">&#8216;roll of wire&#8217; on sale at goldmine-elec.com<\/a>.&nbsp; They came with the wire ends on the same end of the reel, the start end was sticking out of a hole and standing straight out, and the end of the wire was held to the reel with tape, exactly half way around the reel, diametrically opposite from the start.&nbsp; It was obvious that these were meant to be inserted into a circuit board.<\/p>\n<p>I measured both of them with my LC meter, and both measured about 0.93 millihenrys.&nbsp; My meter tends to be off a bit in the millihenry ranges, so I will round off these to 1 millihenry each.<\/p>\n<p>The core of these inductors is air, which cannot saturate like a ferrite or other magnetic core.&nbsp; This type of inductor is most often used for crossover netwotks for speakers.&nbsp; Since a speaker may have to handle high power, tens of watts or more, the crossover network&#8217;s inductors must be able to handle high power, using heavy wire and an air core to prevent saturation.&nbsp; So I believe these &#8216;coils of wire&#8217; were originally made for a speaker crossover network.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>I bought two of these &#8216;roll of wire&#8217; on sale at goldmine-elec.com.&nbsp; They came with the wire ends on the same end of the reel, the start end was sticking out of a hole and standing straight out, and the end of the wire was held to the reel with tape, exactly half way around<a href=\"https:\/\/rustybolt.info\/wordpress\/?p=11679\"> <\/p>\n<p> (Read More&#8230;)<\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-11679","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/11679","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=11679"}],"version-history":[{"count":2,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/11679\/revisions"}],"predecessor-version":[{"id":11681,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/11679\/revisions\/11681"}],"wp:attachment":[{"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=11679"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=11679"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=11679"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}