{"id":12743,"date":"2018-01-31T12:27:14","date_gmt":"2018-01-31T20:27:14","guid":{"rendered":"https:\/\/rustybolt.info\/wordpress\/?p=12743"},"modified":"2018-02-02T13:44:35","modified_gmt":"2018-02-02T21:44:35","slug":"2018-01-31-1khz-wien-bridge-oscillator-kit","status":"publish","type":"post","link":"https:\/\/rustybolt.info\/wordpress\/?p=12743","title":{"rendered":"2018-01-31 1kHz Wien Bridge Oscillator Kit"},"content":{"rendered":"<p>Also photo posted to FB group Building Transistor Radios.<\/p>\n<p>I got several of these Wien Bridge Oscillator kits from an eBay seller in China.&nbsp; They are built using the circuit from&nbsp;<a href=\"http:\/\/\">http:\/\/redcircuits.com\/Page13.htm<\/a><\/p>\n<p>More information can be found on the&nbsp;<a href=\"https:\/\/en.m.wikipedia.org\/wiki\/Wien_bridge_oscillator\">wiki for this oscillator<\/a>.<\/p>\n<p>The kits come with no instructions, so to assemble it, use this red circuits link above.&nbsp; The resistors are all 1%, and the frequency was 1027 Hz, which is fairly accurate.&nbsp; The output level is adjustable with a 500 ohm multiturn pot.&nbsp; The frequency is fixed, there is not enough room on the PC board to add capacitors or resistors, however the existing ones could be replaced.&nbsp;&nbsp;<\/p>\n<p>My one gripe is that the circuit actually works on 9 volts, but the supply says 12V, and three volts are dropped across a 200 ohm resistor which is part of the shunt regulator.&nbsp; The other part is the 9 volt Zener diode to limit the voltage, sort of.&nbsp; I didn&#8217;t solder in the Zener diode because I&#8217;m going to use a 9V supply.&nbsp; When I connected it to the variable supply, I had to turn it up to more than 12V in order to get the voltage to 9V.&nbsp; In other words, more than 3V was being dropped across the 200 ohm resistor and polarity protection rectifier.&nbsp; This means very little or no current is flowing through the 9V Zener.&nbsp; The 200 ohm resistor gets quite warm.&nbsp; And to get the regulation, this resistor needs to be lower, maybe 100 ohms, depending on the supply voltage.&nbsp; The Zener has a 100 uF capacitor across it, to filter out any hum from the supply.&nbsp; This might not be enough.&nbsp; The PC board is small so there is very little room for adding parts.<\/p>\n<p><a href=\"https:\/\/rustybolt.info\/wordpress\/wp-content\/uploads\/2018\/02\/IMG_20180201_1644062.jpg\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/rustybolt.info\/wordpress\/wp-content\/uploads\/2018\/02\/IMG_20180201_1644062.jpg\" alt=\"\" class=\"wp-image-12742 alignnone size-full\" width=\"2228\" height=\"2157\" srcset=\"https:\/\/rustybolt.info\/wordpress\/wp-content\/uploads\/2018\/02\/IMG_20180201_1644062.jpg 2228w, https:\/\/rustybolt.info\/wordpress\/wp-content\/uploads\/2018\/02\/IMG_20180201_1644062-300x290.jpg 300w, https:\/\/rustybolt.info\/wordpress\/wp-content\/uploads\/2018\/02\/IMG_20180201_1644062-768x744.jpg 768w, https:\/\/rustybolt.info\/wordpress\/wp-content\/uploads\/2018\/02\/IMG_20180201_1644062-1024x991.jpg 1024w\" sizes=\"auto, (max-width: 2228px) 100vw, 2228px\" \/><\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Also photo posted to FB group Building Transistor Radios. I got several of these Wien Bridge Oscillator kits from an eBay seller in China.&nbsp; They are built using the circuit from&nbsp;http:\/\/redcircuits.com\/Page13.htm More information can be found on the&nbsp;wiki for this oscillator. The kits come with no instructions, so to assemble it, use this red circuits<a href=\"https:\/\/rustybolt.info\/wordpress\/?p=12743\"> <\/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":[8,339,17,1],"tags":[341,340],"class_list":["post-12743","post","type-post","status-publish","format-standard","hentry","category-audio","category-generators-oscillators","category-meters-and-test-equipment","category-uncategorized","tag-oscillator","tag-wien-bridge"],"_links":{"self":[{"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/12743","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=12743"}],"version-history":[{"count":2,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/12743\/revisions"}],"predecessor-version":[{"id":12745,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/12743\/revisions\/12745"}],"wp:attachment":[{"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=12743"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=12743"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=12743"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}