From YT reply to Neilgn 2017-08-20<\/p>\n
Take any NPN transistor and measure the gain, and write it down. Then put a 1k resistor in series with the transistor’s emitter and connect the emitter to positive and base to negative of a power supply. Adjust the voltage until 2 or 3 volts are across the 1k resistor. The voltage across the E-B junction should be more than 5 volts, maybe 7 or 8 V. Now remove the transistor and measure the gain again. When I did this years ago, the gain went from over 200 to less than 150. I don’t know what causes this, but I’ve never seen any transistor that doesn’t do it. When I did this, I cut off the leads of the transistor afterwards, because I was concerned about the damage to the transistor. <\/p>\n
The JT is only about 50 to 60 percent efficient, so if you have just a single current limiting resistor, it and the LED could be more efficient than the JT.<\/p>\n","protected":false},"excerpt":{"rendered":"
From YT reply to Neilgn 2017-08-20 Take any NPN transistor and measure the gain, and write it down. Then put a 1k resistor in series with the transistor’s emitter and connect the emitter to positive and base to negative of a power supply. Adjust the voltage until 2 or 3 volts are across the 1k <\/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":[4,204,80,1],"tags":[],"class_list":["post-12329","post","type-post","status-publish","format-standard","hentry","category-joule-thief-smps-dc-dc","category-measurement-environment","category-transistors","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/12329","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=12329"}],"version-history":[{"count":3,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/12329\/revisions"}],"predecessor-version":[{"id":12338,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/12329\/revisions\/12338"}],"wp:attachment":[{"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=12329"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=12329"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=12329"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}