{"id":7621,"date":"2018-09-23T21:34:00","date_gmt":"2018-09-23T20:34:00","guid":{"rendered":"http:\/\/www.bartola.co.uk\/valves\/?p=7621"},"modified":"2018-09-23T21:34:00","modified_gmt":"2018-09-23T20:34:00","slug":"cap-multiplier-test","status":"publish","type":"post","link":"https:\/\/www.bartola.co.uk\/valves\/2018\/09\/23\/cap-multiplier-test\/","title":{"rendered":"Cap Multiplier test"},"content":{"rendered":"

I managed to find the time this weekend and do a quick test on the Cap Multiplier PCB. It turned out that I missed a thermal pad on the PCB so had to add a short jumper. Nothing major, but the PCB needs adjustment.<\/p>\n

Below is the diagram of one of the ways the PCB can be used. This is the most complex circuit, a basic one can be wired instead. The CCS (M1 and M3) provides better PSRR as well as regulation. A stable current is fed to R4 and P1 to set the voltage. C2 is the cap multiplier and the M5 used can be any suitable MOSFET. T4 provides current surge protection to the MOSFET as well as short circuit. R7 sets the current limit.<\/p>\n

The boards fits various film caps, I have some WIMA DC Link which are great and fit perfectly:<\/p>\n


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I ran a test at 200V \/ 20mA. The raw supply was 230V. The workbench is quite noisy and the HT power transformer noise is picked up by the circuit. You should expect a 100dB PSRR. On the below, you can see 50dB and this is because the 50Hz and harmonics from the mains TX get in anyway. Otherwise the rest is flat down to 100dBu!<\/p>\n

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This is a great circuit. Can be used from a phono stage to a preamp or a proper power amp like a 300B SE.<\/p>\n

I think despite the PCB error, I have enough boards for my personal use. Not sure I will run a production batch for this. It may be useful to some, but not probably enough to justify the production PCB.<\/p>\n

 <\/p>\n","protected":false},"excerpt":{"rendered":"

I managed to find the time this weekend and do a quick test on the Cap Multiplier PCB. It turned out that I missed a thermal pad on the PCB so had to add a short jumper. Nothing major, but the PCB needs adjustment. Below is the diagram of one of the ways the PCB … Continue reading “Cap Multiplier test”<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2},"jetpack_post_was_ever_published":false},"categories":[673,530,159],"tags":[894,941,1185,1175,1184,1183],"class_list":["post-7621","post","type-post","status-publish","format-standard","hentry","category-300b-amp","category-components","category-power-supplies","tag-bartola-pcb","tag-c3m0280090d","tag-cap-multiplier","tag-capacitor-multiplier","tag-power-supply","tag-wima-dc-link"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p2r2tK-1YV","jetpack_likes_enabled":true,"jetpack-related-posts":[],"_links":{"self":[{"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/posts\/7621","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/comments?post=7621"}],"version-history":[{"count":1,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/posts\/7621\/revisions"}],"predecessor-version":[{"id":7626,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/posts\/7621\/revisions\/7626"}],"wp:attachment":[{"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/media?parent=7621"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/categories?post=7621"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/tags?post=7621"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}