From FB group Building Transistor Radios 2018-08-24 – The discussion was about the OTL complementary symmetry audio amplifier that Mr. Barnett has posted several times to the group, which uses a 2N3904 and 2N3906. <\/p>\n
Willie Barnett
\nLet’s talk about current. Suppose your amp has a 9V supply. When the output transistor is turned fully on, the peak current can be as much as 1 amp through the 8 ohm load. The absolute maximum rating for the 2N3904 or ‘6 is 0.2 amps. So the peak current is *five times* the absolute maximum rating for those transistors. Now do you understand why I have said that you should not<\/u> use the 2N3904, 2N3906 or the BC547 or BC 557. These small signal transistors will go into thermal runaway. If they don’t, you’re just lucky.<\/p>\n
The better choice is to use the PN2222A \/ PN2907A or the BC337 \/ BC327 or the C8050 \/ C8550. These were made for this amplifier.<\/p>\n","protected":false},"excerpt":{"rendered":"
From FB group Building Transistor Radios 2018-08-24 – The discussion was about the OTL complementary symmetry audio amplifier that Mr. Barnett has posted several times to the group, which uses a 2N3904 and 2N3906. Willie Barnett Let’s talk about current. Suppose your amp has a 9V supply. When the output transistor is turned fully on, <\/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":[347,8,80],"tags":[],"class_list":["post-13053","post","type-post","status-publish","format-standard","hentry","category-amplifier","category-audio","category-transistors"],"_links":{"self":[{"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/13053","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=13053"}],"version-history":[{"count":1,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/13053\/revisions"}],"predecessor-version":[{"id":13054,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/13053\/revisions\/13054"}],"wp:attachment":[{"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=13053"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=13053"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=13053"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}